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jets</title> <meta name="description" content="Search results for: two unequal jets"> <meta name="keywords" content="two unequal jets"> <meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1, maximum-scale=1, user-scalable=no"> <meta charset="utf-8"> <link href="https://cdn.waset.org/favicon.ico" type="image/x-icon" rel="shortcut icon"> <link href="https://cdn.waset.org/static/plugins/bootstrap-4.2.1/css/bootstrap.min.css" rel="stylesheet"> <link href="https://cdn.waset.org/static/plugins/fontawesome/css/all.min.css" rel="stylesheet"> <link href="https://cdn.waset.org/static/css/site.css?v=150220211555" rel="stylesheet"> </head> <body> <header> <div class="container"> <nav class="navbar navbar-expand-lg navbar-light"> <a class="navbar-brand" href="https://waset.org"> <img src="https://cdn.waset.org/static/images/wasetc.png" alt="Open Science Research Excellence" title="Open Science Research Excellence" /> </a> <button class="d-block d-lg-none navbar-toggler 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id="custom-search-input"> <div class="input-group"> <i class="fas fa-search"></i> <input type="text" class="search-query" name="q" placeholder="Author, Title, Abstract, Keywords" value="two unequal jets"> <input type="submit" class="btn_search" value="Search"> </div> </div> </form> </div> </div> <div class="row mt-3"> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Commenced</strong> in January 2007</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Frequency:</strong> Monthly</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Edition:</strong> International</div> </div> </div> <div class="col-sm-3"> <div class="card"> <div class="card-body"><strong>Paper Count:</strong> 202</div> </div> </div> </div> <h1 class="mt-3 mb-3 text-center" style="font-size:1.6rem;">Search results for: two unequal jets</h1> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">202</span> Dynamical and Thermal Study of Twin Impinging Jets a Vertical Plate with Various Jet Velocities and Impinging Distance</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Louaifi%20Hamaili%20Samira">Louaifi Hamaili Samira</a>, <a href="https://publications.waset.org/abstracts/search?q=Mataoui%20Amina"> Mataoui Amina</a>, <a href="https://publications.waset.org/abstracts/search?q=Cheraitia%20Tadjeddine"> Cheraitia Tadjeddine</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This investigation proposes a numerical analysis of two turbulent parallel jets impinging a heated plate. The heat transfer enhancement is carried out according of the main parameters of the jet-wall interaction. The numerical solution of the stationary equations (RANS) is performed by the finite volume method using the k - ε model. A parametric study is performed to evaluate simultaneously the effect of nozzle-plate distance and velocity ratios in the range 0≤λ≤1. It is found that good local cooling is obtained for λ= 0.25 when the impinging distance is between 4w and 8w than for velocity ratios λ=1 and λ= 0.75. On the other hand, for impinging distances exceeding 8w, the velocity ratio λ =0.75 is more appropriate for good local cooling of the plate. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=two%20unequal%20jets" title="two unequal jets">two unequal jets</a>, <a href="https://publications.waset.org/abstracts/search?q=turbulence" title=" turbulence"> turbulence</a>, <a href="https://publications.waset.org/abstracts/search?q=mixing" title=" mixing"> mixing</a>, <a href="https://publications.waset.org/abstracts/search?q=heat%20transfer" title=" heat transfer"> heat transfer</a>, <a href="https://publications.waset.org/abstracts/search?q=CFD" title=" CFD"> CFD</a> </p> <a href="https://publications.waset.org/abstracts/188280/dynamical-and-thermal-study-of-twin-impinging-jets-a-vertical-plate-with-various-jet-velocities-and-impinging-distance" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/188280.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">32</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">201</span> Characterization of Plunging Water Jets in Crossflows: Experimental and Numerical Studies</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Mina%20Esmi%20Jahromi">Mina Esmi Jahromi</a>, <a href="https://publications.waset.org/abstracts/search?q=Mehdi%20Khiadani"> Mehdi Khiadani</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Plunging water jets discharging into turbulent crossflows are capable of providing efficient air water interfacial area, which is desirable for the process of mass transfer. Although several studies have been dedicated to the air entrainment by water jets impinging into stagnant water, very few studies have focused on the water jets in crossflows. This study investigates development of the two-phase flow as a result of the jet impingements into crossflows by means of image processing technique and CFD simulations. Investigations are also conducted on the oxygen transfer and a correlation is established between the aeration properties and the oxygenation capacity of water jets in crossflows. This study helps the optimal design and the effective operation of the industrial and the environmental equipment incorporating water jets in crossflows. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=air%20entrainment" title="air entrainment">air entrainment</a>, <a href="https://publications.waset.org/abstracts/search?q=CFD%20simulation" title=" CFD simulation"> CFD simulation</a>, <a href="https://publications.waset.org/abstracts/search?q=image%20processing" title=" image processing"> image processing</a>, <a href="https://publications.waset.org/abstracts/search?q=jet%20in%20crossflow" title=" jet in crossflow"> jet in crossflow</a>, <a href="https://publications.waset.org/abstracts/search?q=oxygen%20transfer" title=" oxygen transfer"> oxygen transfer</a>, <a href="https://publications.waset.org/abstracts/search?q=two-phase%20flow" title=" two-phase flow"> two-phase flow</a> </p> <a href="https://publications.waset.org/abstracts/78148/characterization-of-plunging-water-jets-in-crossflows-experimental-and-numerical-studies" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/78148.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">238</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">200</span> Multi-Linear Regression Based Prediction of Mass Transfer by Multiple Plunging Jets</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=S.%20Deswal">S. Deswal</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20Pal"> M. Pal</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The paper aims to compare the performance of vertical and inclined multiple plunging jets and to model and predict their mass transfer capacity by multi-linear regression based approach. The multiple vertical plunging jets have jet impact angle of θ = 90O; whereas, multiple inclined plunging jets have jet impact angle of θ = 600. The results of the study suggests that mass transfer is higher for multiple jets, and inclined multiple plunging jets have up to 1.6 times higher mass transfer than vertical multiple plunging jets under similar conditions. The derived relationship, based on multi-linear regression approach, has successfully predicted the volumetric mass transfer coefficient (KLa) from operational parameters of multiple plunging jets with a correlation coefficient of 0.973, root mean square error of 0.002 and coefficient of determination of 0.946. The results suggests that predicted overall mass transfer coefficient is in good agreement with actual experimental values; thereby suggesting the utility of derived relationship based on multi-linear regression based approach and can be successfully employed in modelling mass transfer by multiple plunging jets. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=mass%20transfer" title="mass transfer">mass transfer</a>, <a href="https://publications.waset.org/abstracts/search?q=multiple%20plunging%20jets" title=" multiple plunging jets"> multiple plunging jets</a>, <a href="https://publications.waset.org/abstracts/search?q=multi-linear%20regression" title=" multi-linear regression"> multi-linear regression</a>, <a href="https://publications.waset.org/abstracts/search?q=earth%20sciences" title=" earth sciences"> earth sciences</a> </p> <a href="https://publications.waset.org/abstracts/5905/multi-linear-regression-based-prediction-of-mass-transfer-by-multiple-plunging-jets" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/5905.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">462</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">199</span> Thermal Performance of a Pair of Synthetic Jets Equipped in Microchannel</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=J.%20Mohammadpour">J. Mohammadpour</a>, <a href="https://publications.waset.org/abstracts/search?q=G.%20E.%20Lau"> G. E. Lau</a>, <a href="https://publications.waset.org/abstracts/search?q=S.%20Cheng"> S. Cheng</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Lee"> A. Lee</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Numerical study was conducted using two synthetic jet actuators attached underneath a micro-channel. By fixing the oscillating frequency and diaphragm amplitude, the effects on the heat transfer within the micro-channel were investigated with two synthetic jets being in-phase and 180° out-of-phase at different orifice spacing. There was a significant benefit identified with two jets being 180° out-of-phase with each other at the orifice spacing of 2 mm. By having this configuration, there was a distinct pattern of vortex forming which disrupts the main channel flow as well as promoting thermal mixing at high velocity within the channel. Therefore, this configuration achieved higher cooling performance compared to the other cases studied in terms of the reduction in the maximum temperature and cooling uniformity in the silicon wafer. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=synthetic%20jets" title="synthetic jets">synthetic jets</a>, <a href="https://publications.waset.org/abstracts/search?q=microchannel" title=" microchannel"> microchannel</a>, <a href="https://publications.waset.org/abstracts/search?q=electronic%20cooling" title=" electronic cooling"> electronic cooling</a>, <a href="https://publications.waset.org/abstracts/search?q=computational%20fluid%20dynamics" title=" computational fluid dynamics"> computational fluid dynamics</a> </p> <a href="https://publications.waset.org/abstracts/126507/thermal-performance-of-a-pair-of-synthetic-jets-equipped-in-microchannel" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/126507.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">198</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">198</span> Geometrical Based Unequal Droplet Splitting Using Microfluidic Y-Junction</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Bahram%20Talebjedi">Bahram Talebjedi</a>, <a href="https://publications.waset.org/abstracts/search?q=Amirmohammad%20Sattari"> Amirmohammad Sattari</a>, <a href="https://publications.waset.org/abstracts/search?q=Ahmed%20Zoher%20Sihorwala"> Ahmed Zoher Sihorwala</a>, <a href="https://publications.waset.org/abstracts/search?q=Mina%20Hoorfar"> Mina Hoorfar</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Among different droplet manipulations, controlled droplet-splitting is of great significance due to its ability to increase throughput and operational capability. Furthermore, unequal droplet-splitting can provide greater flexibility and a wider range of dilution factors. In this study, we developed two-dimensional, time-dependent complex fluid dynamics simulations to model droplet formation in a flow focusing device, followed by splitting in a Y-shaped junction with sub-channels of unequal widths. From the results obtained from the numerical study, we correlated the diameters of the droplets in the sub-channels to the Weber number, thereby demarcating the droplet splitting and non-splitting regimes. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=microfluidics" title="microfluidics">microfluidics</a>, <a href="https://publications.waset.org/abstracts/search?q=unequal%20droplet%20splitting" title=" unequal droplet splitting"> unequal droplet splitting</a>, <a href="https://publications.waset.org/abstracts/search?q=two%20phase%20flow" title=" two phase flow"> two phase flow</a>, <a href="https://publications.waset.org/abstracts/search?q=flow%20focusing%20device" title=" flow focusing device"> flow focusing device</a> </p> <a href="https://publications.waset.org/abstracts/133469/geometrical-based-unequal-droplet-splitting-using-microfluidic-y-junction" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/133469.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">167</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">197</span> Effect of Gravity on the Controlled Cooling of a Steel Block by Impinging Water Jets</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=E.K.K.%20Agyeman">E.K.K. Agyeman</a>, <a href="https://publications.waset.org/abstracts/search?q=P.%20Mousseau"> P. Mousseau</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Sarda"> A. Sarda</a>, <a href="https://publications.waset.org/abstracts/search?q=D.%20Edelin"> D. Edelin</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The uniform and controlled cooling of hot metals by the circulation of water in canals remains a challenge due to the phase change of the water and the high heat fluxes associated with the phase change. This is because, during the cooling process, the phases are not uniformly distributed along the canals with the liquid phase dominating at the entrances of the canals and the gaseous phase dominating towards the exits. The difference in thermal properties between both phases leads to a heterogeneous temperature distribution in the part being cooled. Slowing down the cooling process is also a challenge due to the high heat fluxes associated with the phase change of water. This study investigates the use of multiple water jets for the controlled and homogenous cooling of hot metal parts and the effect of gravity on the effectiveness of the cooling process with a potential application in the cooling of composite forming moulds. A hole is bored at the centre of a steel block along its length. The jets are generated from the holes of a perforated steel pipe which is placed along the centre of the hole bored in the steel block. The evolution of the temperature with respect to time on the external surface of the steel block is measured simultaneously by thermocouples and an infrared camera. Different jet positions are tested in order to identify the jet placement configuration that ensures the most homogenous cooling of the block while the cooling speed is controlled by an intermittent impingement of the jets. In order to study the effect of gravity on the cooling process, a scenario where the jets are oriented in the opposite direction to that of gravity is compared to one where the jets are aligned in the same direction as gravity. It’s observed that orienting the jets in the direction of gravity reduces the effectiveness of the cooling process on the face of the block facing the impinging jets. This is due to the formation of a deeper pool of water due to the effect gravity and of the curved surface of the canal. This deeper pool of water influences the boiling regime characterized by a slower bubble evacuation when compared to the scenario where the jets are opposed to gravity. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=cooling%20speed" title="cooling speed">cooling speed</a>, <a href="https://publications.waset.org/abstracts/search?q=gravity" title=" gravity"> gravity</a>, <a href="https://publications.waset.org/abstracts/search?q=homogenous%20cooling" title=" homogenous cooling"> homogenous cooling</a>, <a href="https://publications.waset.org/abstracts/search?q=jet%20impingement" title=" jet impingement"> jet impingement</a> </p> <a href="https://publications.waset.org/abstracts/112429/effect-of-gravity-on-the-controlled-cooling-of-a-steel-block-by-impinging-water-jets" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/112429.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">121</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">196</span> Location Choice of Firms in an Unequal Length Streets Model: Game Theory Approach as an Extension of the Spoke Model</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Kiumars%20Shahbazi">Kiumars Shahbazi</a>, <a href="https://publications.waset.org/abstracts/search?q=Salah%20Salimian"> Salah Salimian</a>, <a href="https://publications.waset.org/abstracts/search?q=Abdolrahim%20Hashemi%20Dizaj"> Abdolrahim Hashemi Dizaj</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Locating is one of the key elements in success and survival of industrial centers and has great impact on cost reduction of establishment and launching of various economic activities. In this study, streets with unequal length model have been used that is the classic extension of Spoke model; however with unlimited number of streets with uneven lengths. The results showed that the spoke model is a special case of streets with unequal length model. According to the results of this study, if the strategy of enterprises and firms is to select both price and location, there would be no balance in the game. Furthermore, increased length of streets leads to increased profit of enterprises and with increased number of streets, the enterprises choose locations that are far from center (the maximum differentiation), and the enterprises' output will decrease. Moreover, the enterprise production rate will incline toward zero when the number of streets goes to infinity, and complete competition outcome will be achieved. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=locating" title="locating">locating</a>, <a href="https://publications.waset.org/abstracts/search?q=Nash%20equilibrium" title=" Nash equilibrium"> Nash equilibrium</a>, <a href="https://publications.waset.org/abstracts/search?q=streets%20with%20unequal%20length%20model" title=" streets with unequal length model"> streets with unequal length model</a>, <a href="https://publications.waset.org/abstracts/search?q=streets%20with%20unequal%20length%20model" title=" streets with unequal length model"> streets with unequal length model</a> </p> <a href="https://publications.waset.org/abstracts/102562/location-choice-of-firms-in-an-unequal-length-streets-model-game-theory-approach-as-an-extension-of-the-spoke-model" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/102562.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">203</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">195</span> Prediction of Scour Profile Caused by Submerged Three-Dimensional Wall Jets</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Abdullah%20Al%20Faruque">Abdullah Al Faruque</a>, <a href="https://publications.waset.org/abstracts/search?q=Ram%20Balachandar"> Ram Balachandar</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Series of laboratory tests were carried out to study the extent of scour caused by a three-dimensional wall jets exiting from a square cross-section nozzle and into a non-cohesive sand beds. Previous observations have indicated that the effect of the tailwater depth was significant for densimetric Froude number greater than ten. However, the present results indicate that the cut off value could be lower depending on the value of grain size-to-nozzle width ratio. Numbers of equations are drawn out for a better scaling of numerous scour parameters. Also suggested the empirical prediction of scour to predict the scour centre line profile and plan view of scour profile at any particular time. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=densimetric%20froude%20number" title="densimetric froude number">densimetric froude number</a>, <a href="https://publications.waset.org/abstracts/search?q=jets" title=" jets"> jets</a>, <a href="https://publications.waset.org/abstracts/search?q=nozzle" title=" nozzle"> nozzle</a>, <a href="https://publications.waset.org/abstracts/search?q=sand" title=" sand"> sand</a>, <a href="https://publications.waset.org/abstracts/search?q=scour" title=" scour"> scour</a>, <a href="https://publications.waset.org/abstracts/search?q=tailwater" title=" tailwater"> tailwater</a>, <a href="https://publications.waset.org/abstracts/search?q=time" title=" time"> time</a> </p> <a href="https://publications.waset.org/abstracts/18575/prediction-of-scour-profile-caused-by-submerged-three-dimensional-wall-jets" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/18575.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">435</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">194</span> Numerical Studies on Thrust Vectoring Using Shock-Induced Self Impinging Secondary Jets</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=S.%20Vignesh">S. Vignesh</a>, <a href="https://publications.waset.org/abstracts/search?q=N.%20Vishnu"> N. Vishnu</a>, <a href="https://publications.waset.org/abstracts/search?q=S.%20Vigneshwaran"> S. Vigneshwaran</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20Vishnu%20Anand"> M. Vishnu Anand</a>, <a href="https://publications.waset.org/abstracts/search?q=Dinesh%20Kumar%20Babu"> Dinesh Kumar Babu</a>, <a href="https://publications.waset.org/abstracts/search?q=V.%20R.%20Sanal%20Kumar"> V. R. Sanal Kumar</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The study of the primary flow velocity and the self impinging secondary jet flow mixing is important from both the fundamental research and the application point of view. Real industrial configurations are more complex than simple shear layers present in idealized numerical thrust-vectoring models due to the presence of combustion, swirl and confinement. Predicting the flow features of self impinging secondary jets in a supersonic primary flow is complex owing to the fact that there are a large number of parameters involved. Earlier studies have been highlighted several key features of self impinging jets, but an extensive characterization in terms of jet interaction between supersonic flow and self impinging secondary sonic jets is still an active research topic. In this paper numerical studies have been carried out using a validated two-dimensional k-omega standard turbulence model for the design optimization of a thrust vector control system using shock induced self impinging secondary flow sonic jets using non-reacting flows. Efforts have been taken for examining the flow features of TVC system with various secondary jets at different divergent locations and jet impinging angles with the same inlet jet pressure and mass flow ratio. The results from the parametric studies reveal that in addition to the primary to the secondary mass flow ratio the characteristics of the self impinging secondary jets having bearing on an efficient thrust vectoring. We concluded that the self impinging secondary jet nozzles are better than single jet nozzle with the same secondary mass flow rate owing to the fact fixing of the self impinging secondary jet nozzles with proper jet angle could facilitate better thrust vectoring for any supersonic aerospace vehicle. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=fluidic%20thrust%20vectoring" title="fluidic thrust vectoring">fluidic thrust vectoring</a>, <a href="https://publications.waset.org/abstracts/search?q=rocket%20steering" title=" rocket steering"> rocket steering</a>, <a href="https://publications.waset.org/abstracts/search?q=supersonic%20to%20sonic%20jet%20interaction" title=" supersonic to sonic jet interaction"> supersonic to sonic jet interaction</a>, <a href="https://publications.waset.org/abstracts/search?q=TVC%20in%20aerospace%20vehicles" title=" TVC in aerospace vehicles"> TVC in aerospace vehicles</a> </p> <a href="https://publications.waset.org/abstracts/33244/numerical-studies-on-thrust-vectoring-using-shock-induced-self-impinging-secondary-jets" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/33244.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">589</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">193</span> Numerical Study of the Dynamic Behavior of an Air Conditioning with a Muti Confined Swirling Jet</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Mohamed%20Roudane">Mohamed Roudane</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The objective of this study is to know the dynamic behavior of a multi swirling jet used for air conditioning inside a room. To conduct this study, we designed a facility to ensure proper conditions of confinement in which we placed five air blowing devices with adjustable vanes, providing multiple swirling turbulent jets. The jets were issued in the same direction and the same spacing defined between them. This study concerned the numerical simulation of the dynamic mixing of confined swirling multi-jets, and examined the influence of important parameters of a swirl diffuser system on the dynamic performance characteristics. The CFD investigations are carried out by a hybrid mesh to discretize the computational domain. In this work, the simulations have been performed using the finite volume method and FLUENT solver, in which the standard k-ε RNG turbulence model was used for turbulence computations. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=simulation" title="simulation">simulation</a>, <a href="https://publications.waset.org/abstracts/search?q=dynamic%20behavior" title=" dynamic behavior"> dynamic behavior</a>, <a href="https://publications.waset.org/abstracts/search?q=swirl" title=" swirl"> swirl</a>, <a href="https://publications.waset.org/abstracts/search?q=turbulent%20jet" title=" turbulent jet"> turbulent jet</a> </p> <a href="https://publications.waset.org/abstracts/38034/numerical-study-of-the-dynamic-behavior-of-an-air-conditioning-with-a-muti-confined-swirling-jet" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/38034.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">399</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">192</span> An Experimental Investigation of Air Entrainment Due to Water Jets in Crossflows</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Mina%20Esmi%20Jahromi">Mina Esmi Jahromi</a>, <a href="https://publications.waset.org/abstracts/search?q=Mehdi%20Khiadani"> Mehdi Khiadani</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Vertical water jets discharging into free surface turbulent cross flows result in the ingression of a large amount of air in the body of water and form a region of two-phase air-water flow with a considerable interfacial area. This research presents an experimental study of the two-phase bubbly flow using image processing technique. The air ingression and the trajectories of bubble swarms under different experimental conditions are evaluated. The rate of air entrainment and the bubble characteristics such as penetration depth, and dispersion pattern were found to be affected by the most influential parameters of water jet and cross flow including water jet-to-crossflow velocity ratio, water jet falling height, and cross flow depth. This research improves understanding of the underwater flow structure due to the water jet impingement in crossflow and advances the practical applications of water jets such as artificial aeration, circulation, and mixing where crossflow is present. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=air%20entrainment" title="air entrainment">air entrainment</a>, <a href="https://publications.waset.org/abstracts/search?q=image%20processing" title=" image processing"> image processing</a>, <a href="https://publications.waset.org/abstracts/search?q=jet%20in%20cross%20flow" title=" jet in cross flow"> jet in cross flow</a>, <a href="https://publications.waset.org/abstracts/search?q=two-phase%20flow" title=" two-phase flow"> two-phase flow</a> </p> <a href="https://publications.waset.org/abstracts/77882/an-experimental-investigation-of-air-entrainment-due-to-water-jets-in-crossflows" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/77882.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">369</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">191</span> Passive Control of Elliptic Jet by Using Triangular and Truncated Tabs</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Saif%20Akram">Saif Akram</a>, <a href="https://publications.waset.org/abstracts/search?q=E.%20Rathakrishnan"> E. Rathakrishnan</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The mixing promoting efficiency of two identical sharp and truncated vertex triangular tabs offering geometrical blockage of 2.5% each, placed at the exit of a Mach 1.5 elliptic nozzle was studied experimentally. The effectiveness of both the tabs in enhancing the mixing of jets with the ambient air are determined by measuring the Pitot pressure along the jet axis and the jet spread in both the minor and major axes of the elliptic nozzle, covering marginally overexpanded to moderately underexpanded levels at the nozzle exit. The results reveal that both the tabs enhance mixing characteristics of the uncontrolled elliptic jet when placed at minor axis. A core length reduction of 67% is achieved at NPR 3 which is the overexpanded state. Similarly, the core length is reduced by about 67%, 50% and 57% at NPRs of 4, 5 and 6 (underexpanded states) respectively. However, unlike the considerable increment in mixing promoting efficiency by the use of truncated vertex tabs for axisymmetric jets, the effect is not much pronounced for the case of supersonic elliptic jets. The CPD plots for both the cases almost overlap, especially when tabs are placed at minor axis, at all the pressure conditions. While, when the tabs are used at major axis, in the case of overexpanded condition, the sharp vertex triangular tabs act as a better mixing enhancer for the supersonic elliptic jets. For the jet controlled with truncated vertex triangular tabs, the core length reductions are of the same order as those for the sharp vertex triangular tabs. The jet mixing is hardly influenced by the tip effect in case of supersonic elliptic jet. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=elliptic%20jet" title="elliptic jet">elliptic jet</a>, <a href="https://publications.waset.org/abstracts/search?q=tabs" title=" tabs"> tabs</a>, <a href="https://publications.waset.org/abstracts/search?q=truncated" title=" truncated"> truncated</a>, <a href="https://publications.waset.org/abstracts/search?q=triangular" title=" triangular"> triangular</a> </p> <a href="https://publications.waset.org/abstracts/38593/passive-control-of-elliptic-jet-by-using-triangular-and-truncated-tabs" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/38593.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">383</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">190</span> Experimental Investigation of Plane Jets Exiting Five Parallel Channels with Large Aspect Ratio</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Laurentiu%20Moruz">Laurentiu Moruz</a>, <a href="https://publications.waset.org/abstracts/search?q=Jens%20Kitzhofer"> Jens Kitzhofer</a>, <a href="https://publications.waset.org/abstracts/search?q=Mircea%20Dinulescu"> Mircea Dinulescu</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The paper aims to extend the knowledge about jet behavior and jet interaction between five plane unventilated jets with large aspect ratio (AR). The distance between the single plane jets is two times the channel height. The experimental investigation applies 2D Particle Image Velocimetry (PIV) and static pressure measurements. Our study focuses on the influence of two different outlet nozzle geometries (triangular shape with 2 x 7.5° and blunt geometry) with respect to variation of Reynolds number from 5500 - 12000. It is shown that the outlet geometry has a major influence on the jet formation in terms of uniformity of velocity profiles downstream of the sudden expansion. Furthermore, we describe characteristic regions like converging region, merging region and combined region. The triangular outlet geometry generates most uniform velocity distributions in comparison to a blunt outlet nozzle geometry. The blunt outlet geometry shows an unstable behavior where the jets tend to attach to one side of the walls (ceiling) generating a large recirculation region on the opposite side. Static pressure measurements confirm the observation and indicate that the recirculation region is connected to larger pressure drop. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=2D%20particle%20image%20velocimetry" title="2D particle image velocimetry">2D particle image velocimetry</a>, <a href="https://publications.waset.org/abstracts/search?q=parallel%20jet%20interaction" title=" parallel jet interaction"> parallel jet interaction</a>, <a href="https://publications.waset.org/abstracts/search?q=pressure%20drop" title=" pressure drop"> pressure drop</a>, <a href="https://publications.waset.org/abstracts/search?q=sudden%20expansion" title=" sudden expansion"> sudden expansion</a> </p> <a href="https://publications.waset.org/abstracts/68324/experimental-investigation-of-plane-jets-exiting-five-parallel-channels-with-large-aspect-ratio" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/68324.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">276</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">189</span> Comparative Analysis of Turbulent Plane Jets from a Sharp-Edged Orifice, a Beveled-Edge Orifice and a Radially Contoured Nozzle</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ravinesh%20C.%20Deo">Ravinesh C. Deo</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This article investigates through experiments the flow characteristics of plane jets from sharp-edged orifice-plate, beveled-edge and radially contoured nozzle. The first two configurations exhibit saddle-backed velocity profiles while the third shows a top-hat. A vena contracta is found for the jet emanating from orifice at x/h = 3 while the contoured case displays a potential core extending to the range x/h = 5. A spurt in jet pressure on the centerline supports vena contracta for the orifice-jet. Momentum thicknesses and integral length scales elongate linearly with x although the growth of the shear-layer and large-scale eddies for the orifice are greater than the contoured case. The near-field spectrum exhibits higher frequency of the primary eddies that concur with enhanced turbulence intensity. Importantly, highly “turbulent” state of the orifice-jet prevails in the far-field where the spectra confirm more energetic secondary eddies associated with greater flapping amplitude of the orifice-jet. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=orifice" title="orifice">orifice</a>, <a href="https://publications.waset.org/abstracts/search?q=beveled-edge-orifice" title=" beveled-edge-orifice"> beveled-edge-orifice</a>, <a href="https://publications.waset.org/abstracts/search?q=radially%20contoured%20nozzle" title=" radially contoured nozzle"> radially contoured nozzle</a>, <a href="https://publications.waset.org/abstracts/search?q=plane%20jets" title=" plane jets "> plane jets </a> </p> <a href="https://publications.waset.org/abstracts/2295/comparative-analysis-of-turbulent-plane-jets-from-a-sharp-edged-orifice-a-beveled-edge-orifice-and-a-radially-contoured-nozzle" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/2295.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">154</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">188</span> SVM-Based Modeling of Mass Transfer Potential of Multiple Plunging Jets</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Surinder%20Deswal">Surinder Deswal</a>, <a href="https://publications.waset.org/abstracts/search?q=Mahesh%20Pal"> Mahesh Pal</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The paper investigates the potential of support vector machines based regression approach to model the mass transfer capacity of multiple plunging jets, both vertical (θ = 90°) and inclined (θ = 60°). The data set used in this study consists of four input parameters with a total of eighty eight cases. For testing, tenfold cross validation was used. Correlation coefficient values of 0.971 and 0.981 (root mean square error values of 0.0025 and 0.0020) were achieved by using polynomial and radial basis kernel functions based support vector regression respectively. Results suggest an improved performance by radial basis function in comparison to polynomial kernel based support vector machines. The estimated overall mass transfer coefficient, by both the kernel functions, is in good agreement with actual experimental values (within a scatter of ±15 %); thereby suggesting the utility of support vector machines based regression approach. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=mass%20transfer" title="mass transfer">mass transfer</a>, <a href="https://publications.waset.org/abstracts/search?q=multiple%20plunging%20jets" title=" multiple plunging jets"> multiple plunging jets</a>, <a href="https://publications.waset.org/abstracts/search?q=support%20vector%20machines" title=" support vector machines"> support vector machines</a>, <a href="https://publications.waset.org/abstracts/search?q=ecological%20sciences" title=" ecological sciences"> ecological sciences</a> </p> <a href="https://publications.waset.org/abstracts/9906/svm-based-modeling-of-mass-transfer-potential-of-multiple-plunging-jets" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/9906.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">464</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">187</span> Experimental and Numerical Study of Thermal Effects in Variable Density Turbulent Jets </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=DRIS%20Mohammed%20El-Amine">DRIS Mohammed El-Amine</a>, <a href="https://publications.waset.org/abstracts/search?q=BOUNIF%20Abdelhamid"> BOUNIF Abdelhamid</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper considers an experimental and numerical investigation of variable density in axisymmetric turbulent free jets. Special attention is paid to the study of the scalar dissipation rate. In this case, dynamic field equations are coupled to scalar field equations by the density which can vary by the thermal effect (jet heating). The numerical investigation is based on the first and second order turbulence models. For the discretization of the equations system characterizing the flow, the finite volume method described by Patankar (1980) was used. The experimental study was conducted in order to evaluate dynamical characteristics of a heated axisymmetric air flow using the Laser Doppler Anemometer (LDA) which is a very accurate optical measurement method. Experimental and numerical results are compared and discussed. This comparison do not show large difference and the results obtained are in general satisfactory. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Scalar%20dissipation%20rate" title="Scalar dissipation rate">Scalar dissipation rate</a>, <a href="https://publications.waset.org/abstracts/search?q=thermal%20effects" title=" thermal effects"> thermal effects</a>, <a href="https://publications.waset.org/abstracts/search?q=turbulent%20axisymmetric%20jets" title=" turbulent axisymmetric jets"> turbulent axisymmetric jets</a>, <a href="https://publications.waset.org/abstracts/search?q=second%20order%20modelling" title=" second order modelling"> second order modelling</a>, <a href="https://publications.waset.org/abstracts/search?q=Velocimetry%20Laser%20Doppler." title=" Velocimetry Laser Doppler."> Velocimetry Laser Doppler.</a> </p> <a href="https://publications.waset.org/abstracts/19513/experimental-and-numerical-study-of-thermal-effects-in-variable-density-turbulent-jets" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/19513.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">450</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">186</span> A Study on Improvement of the Torque Ripple and Demagnetization Characteristics of a PMSM</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Yong%20Min%20You">Yong Min You</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The study on the torque ripple of Permanent Magnet Synchronous Motors (PMSMs) has been rapidly progressed, which effects on the noise and vibration of the electric vehicle. There are several ways to reduce torque ripple, which are the increase in the number of slots and poles, the notch of the rotor and stator teeth, and the skew of the rotor and stator. However, the conventional methods have the disadvantage in terms of material cost and productivity. The demagnetization characteristic of PMSMs must be attained for electric vehicle application. Due to rare earth supply issue, the demand for Dy-free permanent magnet has been increasing, which can be applied to PMSMs for the electric vehicle. Dy-free permanent magnet has lower the coercivity; the demagnetization characteristic has become more significant. To improve the torque ripple as well as the demagnetization characteristics, which are significant parameters for electric vehicle application, an unequal air-gap model is proposed for a PMSM. A shape optimization is performed to optimize the design variables of an unequal air-gap model. Optimal design variables are the shape of an unequal air-gap and the angle between V-shape magnets. An optimization process is performed by Latin Hypercube Sampling (LHS), Kriging Method, and Genetic Algorithm (GA). Finite element analysis (FEA) is also utilized to analyze the torque and demagnetization characteristics. The torque ripple and the demagnetization temperature of the initial model of 45kW PMSM with unequal air-gap are 10 % and 146.8 degrees, respectively, which are reaching a critical level for electric vehicle application. Therefore, the unequal air-gap model is proposed, and then an optimization process is conducted. Compared to the initial model, the torque ripple of the optimized unequal air-gap model was reduced by 7.7 %. In addition, the demagnetization temperature of the optimized model was also increased by 1.8 % while maintaining the efficiency. From these results, a shape optimized unequal air-gap PMSM has shown the usefulness of an improvement in the torque ripple and demagnetization temperature for the electric vehicle. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=permanent%20magnet%20synchronous%20motor" title="permanent magnet synchronous motor">permanent magnet synchronous motor</a>, <a href="https://publications.waset.org/abstracts/search?q=optimal%20design" title=" optimal design"> optimal design</a>, <a href="https://publications.waset.org/abstracts/search?q=finite%20element%20method" title=" finite element method"> finite element method</a>, <a href="https://publications.waset.org/abstracts/search?q=torque%20ripple" title=" torque ripple"> torque ripple</a> </p> <a href="https://publications.waset.org/abstracts/63559/a-study-on-improvement-of-the-torque-ripple-and-demagnetization-characteristics-of-a-pmsm" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/63559.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">274</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">185</span> SMRF Seismic Response: Unequal Beam Depths</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Babak%20H.%20Mamaqani">Babak H. Mamaqani</a>, <a href="https://publications.waset.org/abstracts/search?q=Alimohammad%20Entezarmahdi"> Alimohammad Entezarmahdi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> There are many researches on parameters affecting seismic behavior of steel moment frames. Great deal of these researches considers cover plate connections with or without haunch and direct beam to column connection for exterior columns. Also there are experimental results for interior connections with equal beam depth on both sides but not much research has been performed on the seismic behavior of joints with unequal beam depth. Based on previous experimental results, a series of companion analyses have been set up considering different beam height and connection detailing configuration to investigate the seismic behavior of the connections. Results of this study indicate that when the differences between beams height on both side increases, use of haunch connection system leads to significant improvement in the seismic response whereas other configurations did not provide satisfying results. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=analytical%20modeling" title="analytical modeling">analytical modeling</a>, <a href="https://publications.waset.org/abstracts/search?q=Haunch%20connection" title=" Haunch connection"> Haunch connection</a>, <a href="https://publications.waset.org/abstracts/search?q=seismic%20design" title=" seismic design"> seismic design</a>, <a href="https://publications.waset.org/abstracts/search?q=unequal%20beam%20depth" title=" unequal beam depth"> unequal beam depth</a> </p> <a href="https://publications.waset.org/abstracts/5887/smrf-seismic-response-unequal-beam-depths" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/5887.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">419</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">184</span> Numerical Investigation of a Slightly Oblique Round Jet Flowing into a Uniform Counterflow Stream</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Amani%20Amamou">Amani Amamou</a>, <a href="https://publications.waset.org/abstracts/search?q=Sabra%20Habli"> Sabra Habli</a>, <a href="https://publications.waset.org/abstracts/search?q=Nejla%20Mahjoub%20Sa%C3%AFd"> Nejla Mahjoub Saïd</a>, <a href="https://publications.waset.org/abstracts/search?q=Philippe%20Bournot"> Philippe Bournot</a>, <a href="https://publications.waset.org/abstracts/search?q=Georges%20Le%20Palec"> Georges Le Palec</a> </p> <p class="card-text"><strong>Abstract:</strong></p> A counterflowing jet is a particular configuration of turbulent jets issuing into a moving ambient which has not carried much attention in literature compared with jet in a coflow or in a crossflow. This is due to the marked instability of the jet in a counterflow coupled with experimental and theoretical difficulties related to the flow inversion phenomenon. Nevertheless, jets in a counterflow are encountered in many engineering applications which required enhanced mixing as combustion, process and environmental engineering. In this work, we propose to investigate a round turbulent jet flowing into a uniform counterflow stream through a numerical approach. A hydrodynamic and thermal study of a slightly oblique round jets issuing into a uniform counterflow stream is carried out for different jet-to-counterflow velocity ratios ranging between 3.1 and 15. It is found that even a slight inclination of the jet in the vertical direction of the flow affects the structure and the velocity field of the counterflowing jet. In addition, the evolution of passive scalar temperature and pertinent length scales are presented at various velocity ratios, confirming that the flow is sensitive to directional perturbations. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=jet" title="jet">jet</a>, <a href="https://publications.waset.org/abstracts/search?q=counterflow" title=" counterflow"> counterflow</a>, <a href="https://publications.waset.org/abstracts/search?q=velocity" title=" velocity"> velocity</a>, <a href="https://publications.waset.org/abstracts/search?q=temperature" title=" temperature"> temperature</a>, <a href="https://publications.waset.org/abstracts/search?q=jet%20inclination" title=" jet inclination"> jet inclination</a> </p> <a href="https://publications.waset.org/abstracts/42541/numerical-investigation-of-a-slightly-oblique-round-jet-flowing-into-a-uniform-counterflow-stream" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/42541.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">269</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">183</span> Reorientation of Anisotropic Particles in Free Liquid Microjets</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Mathias%20Schlenk">Mathias Schlenk</a>, <a href="https://publications.waset.org/abstracts/search?q=Susanne%20Seibt"> Susanne Seibt</a>, <a href="https://publications.waset.org/abstracts/search?q=Sabine%20Rosenfeldt"> Sabine Rosenfeldt</a>, <a href="https://publications.waset.org/abstracts/search?q=Josef%20Breu"> Josef Breu</a>, <a href="https://publications.waset.org/abstracts/search?q=Stephan%20Foerster"> Stephan Foerster</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Thin liquid jets on micrometer scale play an important role in processing such as in fiber fabrication, inkjet printing, but also for sample delivery in modern synchrotron X-ray devices. In all these cases the liquid jets contain solvents and dissolved materials such as polymers, nanoparticles, fibers pigments or proteins. As liquid flow in liquid jets differs significantly from flow in capillaries and microchannels, particle localization and orientation will also be different. This is of critical importance for applications, which depend on well-defined homogeneous particle and fiber distribution and orientation in liquid jets. Investigations of particle orientation in liquid microjets of diluted solutions have been rare, despite their importance. With the arise of micro-focused X-ray beams it has become possible to scan across samples with micrometer resolution to locally analyse structure and orientation of the samples. In the present work, we used this method to scan across liquid microjets to determine the local distribution and orientation of anisotropic particles. The compromise wormlike block copolymer micelles as an example of long flexible fibrous structures, hectorite materials as a model of extended nanosheet structures, and gold nanorods as an illustration of short stiff cylinders to comprise all relevant anisotropic geometries. We find that due to the different velocity profile in the liquid jet, which resembles plug flow, the orientation of the particles which was generated in the capillary is lost or changed into non-oriented or bi-axially orientations depending on the geometrical shape of the particle. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=anisotropic%20particles" title="anisotropic particles">anisotropic particles</a>, <a href="https://publications.waset.org/abstracts/search?q=liquid%20microjets" title=" liquid microjets"> liquid microjets</a>, <a href="https://publications.waset.org/abstracts/search?q=reorientation" title=" reorientation"> reorientation</a>, <a href="https://publications.waset.org/abstracts/search?q=SAXS" title=" SAXS"> SAXS</a> </p> <a href="https://publications.waset.org/abstracts/64389/reorientation-of-anisotropic-particles-in-free-liquid-microjets" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/64389.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">339</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">182</span> Unequal Error Protection of VQ Image Transmission System </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Khelifi%20Mustapha">Khelifi Mustapha</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Moulay%20lakhdar"> A. Moulay lakhdar</a>, <a href="https://publications.waset.org/abstracts/search?q=I.%20Elawady"> I. Elawady </a> </p> <p class="card-text"><strong>Abstract:</strong></p> We will study the unequal error protection for VQ image. We have used the Reed Solomon (RS) Codes as Channel coding because they offer better performance in terms of channel error correction over a binary output channel. One such channel (binary input and output) should be considered if it is the case of the application layer, because it includes all the features of the layers located below and on the what it is usually not feasible to make changes. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=vector%20quantization" title="vector quantization">vector quantization</a>, <a href="https://publications.waset.org/abstracts/search?q=channel%20error%20correction" title=" channel error correction"> channel error correction</a>, <a href="https://publications.waset.org/abstracts/search?q=Reed-Solomon%20channel%20coding" title=" Reed-Solomon channel coding"> Reed-Solomon channel coding</a>, <a href="https://publications.waset.org/abstracts/search?q=application" title=" application"> application</a> </p> <a href="https://publications.waset.org/abstracts/21372/unequal-error-protection-of-vq-image-transmission-system" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/21372.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">365</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">181</span> One-Dimensional Numerical Simulation of the Nonlinear Instability Behavior of an Electrified Viscoelastic Liquid Jet</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Fang%20Li">Fang Li</a>, <a href="https://publications.waset.org/abstracts/search?q=Xie-Yuan%20Yin"> Xie-Yuan Yin</a>, <a href="https://publications.waset.org/abstracts/search?q=Xie-Zhen%20Yin"> Xie-Zhen Yin</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Instability and breakup of electrified viscoelastic liquid jets are involved in various applications such as inkjet printing, fuel atomization, the pharmaceutical industry, electrospraying, and electrospinning. Studying on the instability of electrified viscoelastic liquid jets is of theoretical and practical significance. We built a one-dimensional electrified viscoelastic model to study the nonlinear instability behavior of a perfecting conducting, slightly viscoelastic liquid jet under a radial electric field. The model is solved numerically by using an implicit finite difference scheme together with a boundary element method. It is found that under a radial electric field a viscoelastic liquid jet still evolves into a beads-on-string structure with a thin filament connecting two adjacent droplets as in the absence of an electric field. A radial electric field exhibits limited influence on the decay of the filament thickness in the nonlinear evolution process of a viscoelastic jet, in contrast to its great enhancing effect on the linear instability of the jet. On the other hand, a radial electric field can induce axial non-uniformity of the first normal stress difference within the filament. Particularly, the magnitude of the first normal stress difference near the midpoint of the filament can be greatly decreased by a radial electric field. Decreasing the extensional stress by a radial electric field may found applications in spraying, spinning, liquid bridges and others. In addition, the effect of a radial electric field on the formation of satellite droplets is investigated on the parametric plane of the dimensionless wave number and the electrical Bond number. It is found that satellite droplets may be formed for a larger axial wave number at a larger radial electric field. The present study helps us gain insight into the nonlinear instability characteristics of electrified viscoelastic liquid jets. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=non%20linear%20instability" title="non linear instability">non linear instability</a>, <a href="https://publications.waset.org/abstracts/search?q=one-dimensional%20models" title=" one-dimensional models"> one-dimensional models</a>, <a href="https://publications.waset.org/abstracts/search?q=radial%20electric%20fields" title=" radial electric fields"> radial electric fields</a>, <a href="https://publications.waset.org/abstracts/search?q=viscoelastic%20liquid%20jets" title=" viscoelastic liquid jets "> viscoelastic liquid jets </a> </p> <a href="https://publications.waset.org/abstracts/51607/one-dimensional-numerical-simulation-of-the-nonlinear-instability-behavior-of-an-electrified-viscoelastic-liquid-jet" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/51607.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">391</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">180</span> Numerical Simulation of the Effect of Single and Dual Synthetic Jet on Stall Phenomenon On NACA (National Advisory Committee for Aeronautics) GA(W)-2 Airfoil</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Abbasali%20Abouei%20Mehrizi">Abbasali Abouei Mehrizi</a>, <a href="https://publications.waset.org/abstracts/search?q=Hamid%20Hassanzadeh%20Afrouzi"> Hamid Hassanzadeh Afrouzi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Reducing the drag force increases the efficiency of the aircraft and its better performance. Flow control methods delay the phenomenon of flow separation and consequently reduce the reversed flow phenomenon in the separation region and enhance the performance of the lift force while decreasing the drag force and thus improving the aircraft efficiency. Flow control methods can be divided into active and passive types. The use of synthetic jets actuator (SJA) used in this study for NACA GA (W) -2 airfoil is one of the active flow control methods to prevent stall phenomenon on the airfoil. In this research, the relevant airfoil in different angles of attack with and without jets has been compared by OpenFOAM. Also, after achieving the proper SJA position on the airfoil suction surface, the simultaneous effect of two SJAs has been discussed. It was found to have the best effect at 12% chord (C), close to the airfoil’s leading edge (LE). At 12% chord, SJA decreases the drag significantly with increasing lift, and also, the average lift increase was higher than other situations and was equal to 10.4%. The highest drag reduction was about 5% in SJA=0.25C. Then, due to the positive effects of SJA in the 12% and 25% chord regions, these regions were considered for applying dual jets in two post-stall angles of attack, i.e., 16° and 22°. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=active%20and%20passive%20flow%20control%20methods" title="active and passive flow control methods">active and passive flow control methods</a>, <a href="https://publications.waset.org/abstracts/search?q=computational%20fluid%20dynamics" title=" computational fluid dynamics"> computational fluid dynamics</a>, <a href="https://publications.waset.org/abstracts/search?q=flow%20separation" title=" flow separation"> flow separation</a>, <a href="https://publications.waset.org/abstracts/search?q=synthetic%20jet" title=" synthetic jet"> synthetic jet</a> </p> <a href="https://publications.waset.org/abstracts/163363/numerical-simulation-of-the-effect-of-single-and-dual-synthetic-jet-on-stall-phenomenon-on-naca-national-advisory-committee-for-aeronautics-gaw-2-airfoil" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/163363.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">83</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">179</span> Uniform and Controlled Cooling of a Steel Block by Multiple Jet Impingement and Airflow</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=E.%20K.%20K.%20Agyeman">E. K. K. Agyeman</a>, <a href="https://publications.waset.org/abstracts/search?q=P.%20Mousseau"> P. Mousseau</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Sarda"> A. Sarda</a>, <a href="https://publications.waset.org/abstracts/search?q=D.%20Edelin"> D. Edelin</a> </p> <p class="card-text"><strong>Abstract:</strong></p> During the cooling of hot metals by the circulation of water in canals formed by boring holes in the metal, the rapid phase change of the water due to the high initial temperature of the metal leads to a non homogenous distribution of the phases within the canals. The liquid phase dominates towards the entrance of the canal while the gaseous phase dominates towards the exit. As a result of the different thermal properties of both phases, the metal is not uniformly cooled. This poses a problem during the cooling of moulds, where a uniform temperature distribution is needed in order to ensure the integrity of the part being formed. In this study, the simultaneous use of multiple water jets and an airflow for the uniform and controlled cooling of a steel block is investigated. A circular hole is bored at the centre of the steel block along its length and a perforated steel pipe is inserted along the central axis of the hole. Water jets that impact the internal surface of the steel block are generated from the perforations in the steel pipe when the water within it is put under pressure. These jets are oriented in the opposite direction to that of gravity. An intermittent airflow is imposed in the annular space between the steel pipe and the surface of hole bored in the steel block. The evolution of the temperature with respect to time of the external surface of the block is measured with the help of thermocouples and an infrared camera. Due to the high initial temperature of the steel block (350 °C), the water changes phase when it impacts the internal surface of the block. This leads to high heat fluxes. The strategy used to control the cooling speed of the block is the intermittent impingement of its internal surface by the jets. The intervals of impingement and of non impingement are varied in order to achieve the desired result. An airflow is used during the non impingement periods as an additional regulator of the cooling speed and to improve the temperature homogeneity of the impinged surface. After testing different jet positions, jet speeds and impingement intervals, it’s observed that the external surface of the steel block has a uniform temperature distribution along its length. However, the temperature distribution along its width isn’t uniform with the maximum temperature difference being between the centre of the block and its edge. Changing the positions of the jets has no significant effect on the temperature distribution on the external surface of the steel block. It’s also observed that reducing the jet impingement interval and increasing the non impingement interval slows down the cooling of the block and improves upon the temperature homogeneity of its external surface while increasing the duration of jet impingement speeds up the cooling process. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=cooling%20speed" title="cooling speed">cooling speed</a>, <a href="https://publications.waset.org/abstracts/search?q=homogenous%20cooling" title=" homogenous cooling"> homogenous cooling</a>, <a href="https://publications.waset.org/abstracts/search?q=jet%20impingement" title=" jet impingement"> jet impingement</a>, <a href="https://publications.waset.org/abstracts/search?q=phase%20change" title=" phase change"> phase change</a> </p> <a href="https://publications.waset.org/abstracts/112342/uniform-and-controlled-cooling-of-a-steel-block-by-multiple-jet-impingement-and-airflow" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/112342.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">125</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">178</span> Central Finite Volume Methods Applied in Relativistic Magnetohydrodynamics: Applications in Disks and Jets</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Raphael%20de%20Oliveira%20Garcia">Raphael de Oliveira Garcia</a>, <a href="https://publications.waset.org/abstracts/search?q=Samuel%20Rocha%20de%20Oliveira"> Samuel Rocha de Oliveira</a> </p> <p class="card-text"><strong>Abstract:</strong></p> We have developed a new computer program in Fortran 90, in order to obtain numerical solutions of a system of Relativistic Magnetohydrodynamics partial differential equations with predetermined gravitation (GRMHD), capable of simulating the formation of relativistic jets from the accretion disk of matter up to his ejection. Initially we carried out a study on numerical methods of unidimensional Finite Volume, namely Lax-Friedrichs, Lax-Wendroff, Nessyahu-Tadmor method and Godunov methods dependent on Riemann problems, applied to equations Euler in order to verify their main features and make comparisons among those methods. It was then implemented the method of Finite Volume Centered of Nessyahu-Tadmor, a numerical schemes that has a formulation free and without dimensional separation of Riemann problem solvers, even in two or more spatial dimensions, at this point, already applied in equations GRMHD. Finally, the Nessyahu-Tadmor method was possible to obtain stable numerical solutions - without spurious oscillations or excessive dissipation - from the magnetized accretion disk process in rotation with respect to a central black hole (BH) Schwarzschild and immersed in a magnetosphere, for the ejection of matter in the form of jet over a distance of fourteen times the radius of the BH, a record in terms of astrophysical simulation of this kind. Also in our simulations, we managed to get substructures jets. A great advantage obtained was that, with the our code, we got simulate GRMHD equations in a simple personal computer. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=finite%20volume%20methods" title="finite volume methods">finite volume methods</a>, <a href="https://publications.waset.org/abstracts/search?q=central%20schemes" title=" central schemes"> central schemes</a>, <a href="https://publications.waset.org/abstracts/search?q=fortran%2090" title=" fortran 90"> fortran 90</a>, <a href="https://publications.waset.org/abstracts/search?q=relativistic%20astrophysics" title=" relativistic astrophysics"> relativistic astrophysics</a>, <a href="https://publications.waset.org/abstracts/search?q=jet" title=" jet"> jet</a> </p> <a href="https://publications.waset.org/abstracts/19952/central-finite-volume-methods-applied-in-relativistic-magnetohydrodynamics-applications-in-disks-and-jets" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/19952.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">454</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">177</span> Cavitating Jet Design for Enhanced Drilling Performance</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Abdullah%20Ababtain">Abdullah Ababtain</a>, <a href="https://publications.waset.org/abstracts/search?q=Mouhammad%20El%20Hassan"> Mouhammad El Hassan</a>, <a href="https://publications.waset.org/abstracts/search?q=Hassan%20Assoum"> Hassan Assoum</a>, <a href="https://publications.waset.org/abstracts/search?q=Anas%20Sakout"> Anas Sakout</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper, a brief literature review on cavitation jets is presented in order to introduce the cavitation mechanism, strategies to assess when cavitation occurs, and the factors that influence cavitation in cavitating jets. The objectivity of the cavitation number often used to predict cavitation is also discussed. The results show that cavitation cannot be foreseen just using the cavitation number. Therefore, more efforts are needed to innovate and develop a self-resonating jet geometry that would be maintains the flow and the pressure in the cavitation condition just earlier than the flow acts on the target that would be used in such operating conditions. This study focused on a particular aspect related to improving drilling efficiency and the rate of penetration (ROP). In addition, a discussion on the methods used to measure cavitation and the factors that affect cavitation occurrence will be discussed. Two different types of cavitation nozzles were designed and tested. It has been shown that the self-resonating cavitation nozzle presents greater performance than standard non-resonating nozzle. It is thus concluded that a self-resonating cavitation jet present a high potential for improving drilling performance. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=cavitating%20jet" title="cavitating jet">cavitating jet</a>, <a href="https://publications.waset.org/abstracts/search?q=erosion" title=" erosion"> erosion</a>, <a href="https://publications.waset.org/abstracts/search?q=cavitation%20number" title=" cavitation number"> cavitation number</a>, <a href="https://publications.waset.org/abstracts/search?q=rate%20of%20penetration%20%28ROP%29" title=" rate of penetration (ROP)"> rate of penetration (ROP)</a> </p> <a href="https://publications.waset.org/abstracts/128823/cavitating-jet-design-for-enhanced-drilling-performance" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/128823.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">195</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">176</span> A Study on Improvement of the Electromagnetic Vibration of a Polygon Mirror Scanner Motor</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Yongmin%20You">Yongmin You</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Electric machines for office automation device such as printer and scanner have been required the low noise and vibration performance. Many researches about the low noise and vibration of polygon mirror scanner motor have been also progressed. The noise and vibration of polygon mirror scanner motor can be classified by aerodynamic, structural and electromagnetic. Electromagnetic noise and vibration can be occurred by high cogging torque and nonsinusoidal back EMF. To improve the cogging torque and back EMF characteristic, we apply unequal air-gap. To analyze characteristic of a polygon mirror scanner motor, two dimensional finite element method is used. To minimize the cogging torque of a polygon mirror motor, Kriging based on latin hypercube sampling (LHS) is utilized. Compared to the initial model, the torque ripple of the optimized unequal air-gap model was reduced by 23.4 % while maintaining the back EMF and average torque. To verify the optimal design results, the experiment was performed. We measured the vibration in motors at 23,600 rpm which is the rated velocity. The radial and axial gravitational acceleration of the optimal model were declined more than seven times and three times, respectively. From these results, a shape optimized unequal polygon mirror scanner motor has shown the usefulness of an improvement in the torque ripple and electromagnetic vibration characteristic. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=polygon%20mirror%20scanner%20motor" title="polygon mirror scanner motor">polygon mirror scanner motor</a>, <a href="https://publications.waset.org/abstracts/search?q=optimal%20design" title=" optimal design"> optimal design</a>, <a href="https://publications.waset.org/abstracts/search?q=finite%20element%20method" title=" finite element method"> finite element method</a>, <a href="https://publications.waset.org/abstracts/search?q=vibration" title=" vibration"> vibration</a> </p> <a href="https://publications.waset.org/abstracts/64401/a-study-on-improvement-of-the-electromagnetic-vibration-of-a-polygon-mirror-scanner-motor" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/64401.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">342</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">175</span> Distribution of Dynamical and Energy Parameters in Axisymmetric Air Plasma Jet</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Vitas%20Valin%C4%8Dius">Vitas Valinčius</a>, <a href="https://publications.waset.org/abstracts/search?q=Rolandas%20Uscila"> Rolandas Uscila</a>, <a href="https://publications.waset.org/abstracts/search?q=Viktorija%20Grigaitien%C4%97"> Viktorija Grigaitienė</a>, <a href="https://publications.waset.org/abstracts/search?q=%C5%BDydr%C5%ABnas%20Kavaliauskas"> Žydrūnas Kavaliauskas</a>, <a href="https://publications.waset.org/abstracts/search?q=Romualdas%20K%C4%97%C5%BEelis"> Romualdas Kėželis</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Determination of integral dynamical and energy characteristics of high-temperature gas flows is a very important task of gas-dynamic for hazardous substances destruction systems. They are also always necessary for the investigation of high-temperature turbulent flow dynamics, heat and mass transfer. It is well known that distribution of dynamical and thermal characteristics of high-temperature flows and jets is strongly related to heat flux variation over an imposed area of heating. As is visible from numerous experiments and theoretical considerations, the fundamental properties of an isothermal jet are well investigated. However, the establishment of regularities in high-temperature conditions meets certain specific behavior comparing with moderate-temperature jets and flows. Their structures have not been thoroughly studied yet, especially in the cases of plasma ambient. It is well known that the distribution of local plasma jet parameters in high temperature and isothermal jets and flows may significantly differ. High temperature axisymmetric air jet generated by atmospheric pressure DC arc plasma torch was investigated employing enthalpy probe 3.8∙10-3 m of diameter. Distribution of velocities and temperatures were established in different cross-sections of the plasma jet outflowing from 42∙10-3 m diameter pipe at the average mean velocity of 700 m∙s-1, and averaged temperature of 4000 K. It has been found that gas heating fractionally influences shape and values of a dimensionless profile of velocity and temperature in the main zone of plasma jet and has a significant influence in the initial zone of the plasma jet. The width of the initial zone of the plasma jet has been found to be lesser than in the case of isothermal flow. The relation between dynamical thickness and turbulent number of Prandtl has been established along jet axis. Experimental results were generalized in dimensionless form. The presence of convective heating shows that heat transfer in a moving high-temperature jet also occurs due to heat transfer by moving particles of the jet. In this case, the intensity of convective heat transfer is proportional to the instantaneous value of the flow velocity at a given point in space. Consequently, the configuration of the temperature field in moving jets and flows essentially depends on the configuration of the velocity field. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=plasma%20jet" title="plasma jet">plasma jet</a>, <a href="https://publications.waset.org/abstracts/search?q=plasma%20torch" title=" plasma torch"> plasma torch</a>, <a href="https://publications.waset.org/abstracts/search?q=heat%20transfer" title=" heat transfer"> heat transfer</a>, <a href="https://publications.waset.org/abstracts/search?q=enthalpy%20probe" title=" enthalpy probe"> enthalpy probe</a>, <a href="https://publications.waset.org/abstracts/search?q=turbulent%20number%20of%20Prandtl" title=" turbulent number of Prandtl"> turbulent number of Prandtl</a> </p> <a href="https://publications.waset.org/abstracts/141615/distribution-of-dynamical-and-energy-parameters-in-axisymmetric-air-plasma-jet" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/141615.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">182</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">174</span> Effect of Submerged Water Jet's Cross Section Shapes on Mixing Length</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Mohsen%20Solimani%20Babarsad">Mohsen Solimani Babarsad</a>, <a href="https://publications.waset.org/abstracts/search?q=Mohammad%20Rastgoo"> Mohammad Rastgoo</a>, <a href="https://publications.waset.org/abstracts/search?q=Payam%20Taheri"> Payam Taheri</a> </p> <p class="card-text"><strong>Abstract:</strong></p> One of the important applications of hydraulic jets is used for discharge industrial, agricultural and urban wastewater into the rivers or other ambient water to reduce negative effects of pollutant water. Submerged jets due to turbulent condition can mix large amount of dense pollutant water with ambient flow. This study is conducted to investigate the distribution and length of the mixing zone in hydraulic jet's flow field with change in cross section shapes of nozzle. Toward this end, three shapes of cross section (square, circle and rectangular) and three saline densities current with different concentration are considered in a flume with 600 cm as long, 100 cm as high and 150 cm in width. Various discharges were used to evaluate mixing length for a wide range of densimetric Froude numbers, Frd, from 100 to 550 that is defined at the nozzle. Consequently, the circular nozzle, in comparison with other sections, has a densimetric Froude number 11% higher than square nozzle and 26% higher than rectangular nozzle. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=hydraulic%20jet" title="hydraulic jet">hydraulic jet</a>, <a href="https://publications.waset.org/abstracts/search?q=mixing%20zone" title=" mixing zone"> mixing zone</a>, <a href="https://publications.waset.org/abstracts/search?q=densimetric%20Froude%20number" title=" densimetric Froude number"> densimetric Froude number</a>, <a href="https://publications.waset.org/abstracts/search?q=nozzle" title=" nozzle "> nozzle </a> </p> <a href="https://publications.waset.org/abstracts/9237/effect-of-submerged-water-jets-cross-section-shapes-on-mixing-length" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/9237.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">363</span> </span> </div> </div> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">173</span> Unequal Traveling: How School District System and School District Housing Characteristics Shape the Duration of Families Commuting</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Geyang%20Xia">Geyang Xia</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In many countries, governments have responded to the growing demand for educational resources through school district systems, and there is substantial evidence that school district systems have been effective in promoting inter-district and inter-school equity in educational resources. However, the scarcity of quality educational resources has brought about varying levels of education among different school districts, making it a common choice for many parents to buy a house in the school district where a quality school is located, and they are even willing to bear huge commuting costs for this purpose. Moreover, this is evidenced by the fact that parents of families in school districts with quality education resources have longer average commute lengths and longer average commute distances than parents in average school districts. This "unequal traveling" under the influence of the school district system is more common in school districts at the primary level of education. This further reinforces the differential hierarchy of educational resources and raises issues of inequitable educational public services, education-led residential segregation, and gentrification of school district housing. Against this background, this paper takes Nanjing, a famous educational city in China, as a case study and selects the school districts where the top 10 public elementary schools are located. The study first identifies the spatio-temporal behavioral trajectory dataset of these high-quality school district households by using spatial vector data, decrypted cell phone signaling data, and census data. Then, by constructing a "house-school-work (HSW)" commuting pattern of the population in the school district where the high-quality educational resources are located, and based on the classification of the HSW commuting pattern of the population, school districts with long employment hours were identified. Ultimately, the mechanisms and patterns inherent in this unequal commuting are analyzed in terms of six aspects, including the centrality of school district location, functional diversity, and accessibility. The results reveal that the "unequal commuting" of Nanjing's high-quality school districts under the influence of the school district system occurs mainly in the peripheral areas of the city, and the schools matched with these high-quality school districts are mostly branches of prestigious schools in the built-up areas of the city's core. At the same time, the centrality of school district location and the diversity of functions are the most important influencing factors of unequal commuting in high-quality school districts. Based on the research results, this paper proposes strategies to optimize the spatial layout of high-quality educational resources and corresponding transportation policy measures. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=school-district%20system" title="school-district system">school-district system</a>, <a href="https://publications.waset.org/abstracts/search?q=high%20quality%20school%20district" title=" high quality school district"> high quality school district</a>, <a href="https://publications.waset.org/abstracts/search?q=commuting%20pattern" title=" commuting pattern"> commuting pattern</a>, <a href="https://publications.waset.org/abstracts/search?q=unequal%20traveling" title=" unequal traveling"> unequal traveling</a> </p> <a href="https://publications.waset.org/abstracts/152165/unequal-traveling-how-school-district-system-and-school-district-housing-characteristics-shape-the-duration-of-families-commuting" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/152165.pdf" target="_blank" class="btn btn-primary btn-sm">PDF</a> <span class="bg-info text-light px-1 py-1 float-right rounded"> Downloads <span class="badge badge-light">97</span> </span> </div> </div> <ul class="pagination"> <li class="page-item disabled"><span class="page-link">&lsaquo;</span></li> <li class="page-item active"><span class="page-link">1</span></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=two%20unequal%20jets&page=2">2</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=two%20unequal%20jets&page=3">3</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=two%20unequal%20jets&page=4">4</a></li> <li class="page-item"><a class="page-link" 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