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grooves</title> <meta name="description" content="Search results for: helical grooves"> <meta name="keywords" content="helical grooves"> <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 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action="https://publications.waset.org/abstracts/search"> <div 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="helical grooves"> <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> 132</div> </div> </div> </div> <h1 class="mt-3 mb-3 text-center" style="font-size:1.6rem;">Search results for: helical grooves</h1> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">132</span> Turbulent Flow in Corrugated Pipes with Helical Grooves</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=P.%20Mendes">P. Mendes</a>, <a href="https://publications.waset.org/abstracts/search?q=H.%20Stel"> H. Stel</a>, <a href="https://publications.waset.org/abstracts/search?q=R.%20E.%20M.%20Morales"> R. E. M. Morales</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This article presents a numerical and experimental study of turbulent flow in corrugated pipes with helically “d-type" grooves, for Reynolds numbers between 7500 and 100,000. The ANSYS-CFX software is used to solve the RANS equations with the BSL two equation turbulence model, through the element-based finite-volume method approach. Different groove widths and helix angles are considered. Numerical results are validated with experimental pressure drop measurements for the friction factor. A correlation for the friction factor is also proposed considering the geometric parameters and Reynolds numbers evaluated. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=turbulent%20flow" title="turbulent flow">turbulent flow</a>, <a href="https://publications.waset.org/abstracts/search?q=corrugated%20pipe" title=" corrugated pipe"> corrugated pipe</a>, <a href="https://publications.waset.org/abstracts/search?q=helical" title=" helical"> helical</a>, <a href="https://publications.waset.org/abstracts/search?q=numerical" title=" numerical"> numerical</a>, <a href="https://publications.waset.org/abstracts/search?q=experimental" title=" experimental"> experimental</a>, <a href="https://publications.waset.org/abstracts/search?q=friction%20factor" title=" friction factor"> friction factor</a>, <a href="https://publications.waset.org/abstracts/search?q=correlation" title=" correlation"> correlation</a> </p> <a href="https://publications.waset.org/abstracts/17407/turbulent-flow-in-corrugated-pipes-with-helical-grooves" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/17407.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">484</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">131</span> Flow inside Micro-Channel Bounded by Superhydrophobic Surface with Eccentric Micro-Grooves</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Yu%20Chen">Yu Chen</a>, <a href="https://publications.waset.org/abstracts/search?q=Weiwei%20Ren"> Weiwei Ren</a>, <a href="https://publications.waset.org/abstracts/search?q=Xiaojing%20Mu"> Xiaojing Mu</a>, <a href="https://publications.waset.org/abstracts/search?q=Feng%20Zhang"> Feng Zhang</a>, <a href="https://publications.waset.org/abstracts/search?q=Yi%20Xu"> Yi Xu</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The superhydrophobic surface is widely used to reduce friction for the flow inside micro-channel and can be used to control/manipulate fluid, cells and even proteins in lab-on-chip. Fabricating micro grooves on hydrophobic surfaces is a common method to obtain such superhydrophobic surface. This study utilized the numerical method to investigate the effect of eccentric micro-grooves on the friction of flow inside micro-channel. A detailed parametric study was conducted to reveal how the eccentricity of micro-grooves affects the micro-channel flow under different grooves sizes, channel heights, Reynolds number. The results showed that the superhydrophobic surface with eccentric micro-grooves induces less friction than the counter part with aligning micro-grooves, which means requiring less power for pumps. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=eccentricity" title="eccentricity">eccentricity</a>, <a href="https://publications.waset.org/abstracts/search?q=micro-channel" title=" micro-channel"> micro-channel</a>, <a href="https://publications.waset.org/abstracts/search?q=micro-grooves" title=" micro-grooves"> micro-grooves</a>, <a href="https://publications.waset.org/abstracts/search?q=superhydrophobic%20surface" title=" superhydrophobic surface"> superhydrophobic surface</a> </p> <a href="https://publications.waset.org/abstracts/62094/flow-inside-micro-channel-bounded-by-superhydrophobic-surface-with-eccentric-micro-grooves" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/62094.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">331</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">130</span> Temperature Distribution Simulation of Divergent Fluid Flow with Helical Arrangement</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ehan%20Sabah%20Shukri">Ehan Sabah Shukri</a>, <a href="https://publications.waset.org/abstracts/search?q=Wirachman%20Wisnoe"> Wirachman Wisnoe</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Numerical study is performed to investigate the temperature distribution in an annular diffuser fitted with helical tape hub. Different pitches (Y = 20 mm, and Y = 30 mm) for the helical tape are studied with different heights (H = 20 mm, 22 mm, and 24 mm) to be compared. The geometry of the annular diffuser and the inlet condition for both hub arrangements are kept constant. The result obtains that using helical tape insert with different pitches and different heights will force the temperature to distribute in a helical direction; however the use of helical tape hub with height (H = 22 mm) for both pitches enhance the temperature distribution in a good manner. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=helical%20tape" title="helical tape">helical tape</a>, <a href="https://publications.waset.org/abstracts/search?q=divergent%20fluid%20flow" title=" divergent fluid flow"> divergent fluid flow</a>, <a href="https://publications.waset.org/abstracts/search?q=temperature%20distribution" title=" temperature distribution"> temperature distribution</a>, <a href="https://publications.waset.org/abstracts/search?q=swirl%20flow" title=" swirl flow"> swirl flow</a>, <a href="https://publications.waset.org/abstracts/search?q=CFD" title=" CFD"> CFD</a> </p> <a href="https://publications.waset.org/abstracts/12774/temperature-distribution-simulation-of-divergent-fluid-flow-with-helical-arrangement" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/12774.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">448</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">129</span> Heat Transfer Analysis of Helical Grooved Passages near the Leading Edge Region in Gas Turbine Blade</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Harishkumar%20Kamath">Harishkumar Kamath</a>, <a href="https://publications.waset.org/abstracts/search?q=Chandrakant%20R.%20Kini"> Chandrakant R. Kini</a>, <a href="https://publications.waset.org/abstracts/search?q=N.%20Yagnesh%20Sharma"> N. Yagnesh Sharma</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Gas turbines are highly effective engineered prime movers for converting energy from thermal form (combustion stage) to mechanical form – are widely used for propulsion and power generation systems. One method of increasing both the power output and thermal efﬁciency is to increase the temperature of the gas entering the turbine. In the advanced gas turbines of today, the turbine inlet temperature can be as high as 1500°C; however, this temperature exceeds the melting temperature of the metal blade. With modern gas turbines operating at extremely high temperatures, it is necessary to implement various cooling methods, so the turbine blades and vanes endure in the path of the hot gases. Merely passing coolant air through the blade does not provide adequate cooling; therefore, it is necessary to implement techniques that will further enhance the heat transfer from the blade walls. It is seen that by incorporating helical grooved passages into the leading edge built on turbulence and higher flow rates through the passages, the blade can be cooled effectively. It seen from the analysis helical grooved passages with diameter 5 mm, helical pitch of 50 mm and 8 starts results in better cooling of turbine blade and gives the best thermal performance. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=blade%20cooling" title="blade cooling">blade cooling</a>, <a href="https://publications.waset.org/abstracts/search?q=helical%20grooves" title=" helical grooves"> helical grooves</a>, <a href="https://publications.waset.org/abstracts/search?q=leading%20edge" title=" leading edge"> leading edge</a>, <a href="https://publications.waset.org/abstracts/search?q=numerical%20analysis" title=" numerical analysis"> numerical analysis</a> </p> <a href="https://publications.waset.org/abstracts/60786/heat-transfer-analysis-of-helical-grooved-passages-near-the-leading-edge-region-in-gas-turbine-blade" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/60786.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">263</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">128</span> Fin Efficiency of Helical Fin with Fixed Fin Tip Temperature Boundary Condition</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Richard%20G.%20Carranza">Richard G. Carranza</a>, <a href="https://publications.waset.org/abstracts/search?q=Juan%20Ospina"> Juan Ospina</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The fin efficiency for a helical fin with a fixed fin tip (or arbitrary) temperature boundary condition is presented. Firstly, the temperature profile throughout the fin is determined via an energy balance around the fin itself. Secondly, the fin efficiency is formulated by integrating across the entire surface of the helical fin. An analytical expression for the fin efficiency is presented and compared with the literature for accuracy. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=efficiency" title="efficiency">efficiency</a>, <a href="https://publications.waset.org/abstracts/search?q=fin" title=" fin"> fin</a>, <a href="https://publications.waset.org/abstracts/search?q=heat" title=" heat"> heat</a>, <a href="https://publications.waset.org/abstracts/search?q=helical" title=" helical"> helical</a>, <a href="https://publications.waset.org/abstracts/search?q=transfer" title=" transfer"> transfer</a> </p> <a href="https://publications.waset.org/abstracts/24252/fin-efficiency-of-helical-fin-with-fixed-fin-tip-temperature-boundary-condition" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/24252.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">684</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">127</span> Flow Separation Control on an Aerofoil Using Grooves</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Neel%20K.%20Shah">Neel K. Shah</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Wind tunnel tests have been performed at The University of Manchester to investigate the impact of surface grooves of a trapezoidal planform on flow separation on a symmetrical aerofoil. A spanwise array of the grooves has been applied around the maximum thickness location of the upper surface of an NACA-0015 aerofoil. The aerofoil has been tested in a two-dimensional set-up in a low-speed wind tunnel at an angle of attack (AoA) of 3° and a chord-based Reynolds number (Re) of ~2.7 x 105. A laminar separation bubble developed on the aerofoil at low AoA. It has been found that the grooves shorten the streamwise extent of the separation bubble by shedding a pair of counter-rotating vortices. However, the increase in leading-edge suction due to the shorter bubble is not significant since the creation of the grooves results in a decrease of surface curvature and an increase in blockage (increase in surface pressure). Additionally, the increased flow mixing by the grooves thickens the boundary layer near the trailing edge of the aerofoil also contributes to this limitation. As a result of these competing effects, the improvement in the pressure-lift and pressure-drag coefficients are small, i.e., by ~1.30% and ~0.30%, respectively, at 3° AoA. Crosswire anemometry shows that the grooves increase turbulence intensity and Reynolds stresses in the wake, thus indicating an increase in viscous drag. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=aerofoil%20flow%20control" title="aerofoil flow control">aerofoil flow control</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=grooves" title=" grooves"> grooves</a>, <a href="https://publications.waset.org/abstracts/search?q=vortices" title=" vortices"> vortices</a> </p> <a href="https://publications.waset.org/abstracts/63410/flow-separation-control-on-an-aerofoil-using-grooves" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/63410.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">315</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">126</span> Temperature Distribution Enhancement in a Conical Diffuser Fitted with Helical Screw-Tape with and without Center-Rod</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ehan%20Sabah%20Shukri">Ehan Sabah Shukri</a>, <a href="https://publications.waset.org/abstracts/search?q=Wirachman%20Wisnoe"> Wirachman Wisnoe</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Temperature distribution investigation in a conical diffuser fitted with helical screw-tape with and without center-rod is studied numerically. A helical screw-tape is inserted in the diffuser to create swirl flow that helps to enhance the temperature distribution rate with inlet Reynolds number 4.3 x 104. Three pitch lengths ratios (Y/L = 0.153, 0.23 and 0.307) for the helical screw-tape with and without center-rod are simulated and compared. The geometry of the conical diffuser and the inlet condition for both arrangements are kept constant. Numerical findings show that the helical screw-tape inserts without center-rod perform significantly better than the helical tape inserts with center-rod in the conical diffuser. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=diffuser" title="diffuser">diffuser</a>, <a href="https://publications.waset.org/abstracts/search?q=temperature%20distribution" title=" temperature distribution"> temperature distribution</a>, <a href="https://publications.waset.org/abstracts/search?q=CFD" title=" CFD"> CFD</a>, <a href="https://publications.waset.org/abstracts/search?q=pitch%20ratio" title=" pitch ratio"> pitch ratio</a> </p> <a href="https://publications.waset.org/abstracts/45021/temperature-distribution-enhancement-in-a-conical-diffuser-fitted-with-helical-screw-tape-with-and-without-center-rod" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/45021.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">409</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">125</span> Effect of Elastic Modulus Anisotropy on Helical Piles Behavior in Sandy Soil</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Reza%20Ziaie%20Moayed">Reza Ziaie Moayed</a>, <a href="https://publications.waset.org/abstracts/search?q=Javad%20Shamsi%20Soosahab"> Javad Shamsi Soosahab</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Helical piles are being used extensively in engineering applications all over the world. There are insufficient studies on the helical piles' behavior in anisotropic soils. In this paper, numerical modeling was adopted to investigate the effect of elastic modulus anisotropy on helical pile behavior resting on anisotropic sand by using a finite element limit analysis. The load-displacement behavior of helical piles under compression and tension loads is investigated in different relative densities of soils, and the effect of the ratio of horizontal elastic modulus with respect to vertical elastic modulus (EH/EV) is evaluated. The obtained results illustrate that in sandy soils, the anisotropic ratio of elastic modulus (EH/EV) has notable effect on bearing capacity of helical piles in different relative density. Therefore, it may be recommended that the effect of anisotropic condition of soil elastic modulus should be considered in helical piles behavior. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=helical%20piles" title="helical piles">helical piles</a>, <a href="https://publications.waset.org/abstracts/search?q=bearing%20capacity" title=" bearing capacity"> bearing capacity</a>, <a href="https://publications.waset.org/abstracts/search?q=numerical%20modeling" title=" numerical modeling"> numerical modeling</a>, <a href="https://publications.waset.org/abstracts/search?q=soil%20anisotropy" title=" soil anisotropy"> soil anisotropy</a> </p> <a href="https://publications.waset.org/abstracts/126818/effect-of-elastic-modulus-anisotropy-on-helical-piles-behavior-in-sandy-soil" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/126818.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">163</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">124</span> Analysis of Behaviors of Single and Group Helical Piles in Sands from Experiment Results</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Jongho%20Park">Jongho Park</a>, <a href="https://publications.waset.org/abstracts/search?q=Junwon%20Lee"> Junwon Lee</a>, <a href="https://publications.waset.org/abstracts/search?q=Byeonghyun%20Choi"> Byeonghyun Choi</a>, <a href="https://publications.waset.org/abstracts/search?q=Kicheol%20Lee"> Kicheol Lee</a>, <a href="https://publications.waset.org/abstracts/search?q=Dongwook%20Kim"> Dongwook Kim</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The typically-used oil sand plant foundations are driven pile or drilled shaft. With more strict environmental regulations world widely, it became more important to completely remove the foundation during the stage of plant demolition. However, it is difficult to remove driven piles or drilled shafts that are installed at a deeper and stronger depth to gain more bearing pile capacity. The helical pile can be easily removed after its use and recycled; therefore it is suitable for oil sand plant foundation. This study analyzes the behavior of helical piles in sands. Axial pile load tests were carried out the varying spacing of helix plates (helices), rotation speed and weight of axial loading during pile installation. From the experiments, optimal helix plate spacing, rotation speed, axial loading during installation were determined. In addition, the behavior of helical pile groups was examined varying pile spacing. Finally, the behavior of single helical piles and that of group helical piles were compared. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=oil%20sand%20plant" title="oil sand plant">oil sand plant</a>, <a href="https://publications.waset.org/abstracts/search?q=pile%20load%20test" title=" pile load test"> pile load test</a>, <a href="https://publications.waset.org/abstracts/search?q=helical%20pile" title=" helical pile"> helical pile</a>, <a href="https://publications.waset.org/abstracts/search?q=group%20helical%20pile" title=" group helical pile"> group helical pile</a>, <a href="https://publications.waset.org/abstracts/search?q=behavior" title=" behavior"> behavior</a> </p> <a href="https://publications.waset.org/abstracts/95163/analysis-of-behaviors-of-single-and-group-helical-piles-in-sands-from-experiment-results" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/95163.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">123</span> The Inversion of Helical Twist Sense in Liquid Crystal by Spectroscopy Methods</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Anna%20Drzewicz">Anna Drzewicz</a>, <a href="https://publications.waset.org/abstracts/search?q=Marzena%20Tykarska"> Marzena Tykarska</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The chiral liquid crystal phases form the helicoidal structure, which is characterized by the helical pitch and the helical twist sense. In anticlinic smectic phase with antiferroelectric properties three types of helix temperature dependence have been obtained: increased helical pitch with temperature and right-handed helix, decreased helical pitch with temperature and left-handed helix and the inversion of both. The change of helical twist sense may be observed during the transition from one liquid crystal phase to another or within one phase for the same substance. According to Gray and McDonnell theory, the helical handedness depends on the absolute configuration of the assymetric carbon atom and its position related to the rigid core of the molecule. However, this theory does not explain the inversion of helical twist sense phenomenon. It is supposed, that it may be caused by the presence of different conformers with opposite handendess, which concentration may change with temperature. In this work, the inversion of helical twist sense in the chiral liquid crystals differing in the length of alkyl chain, in the substitution the benzene ring by fluorine atoms and in the type of helix handedness was tested by vibrational spectroscopy (infrared and raman spectroscopy) and by nuclear magnetic resonance spectroscopy. The results obtained from the vibrational spectroscopy confirm the presence of different conformers. Moreover, the analysis of nuclear magnetic resonance spectra is very useful to check, on which structural fragments the change of conformations are important for the change of helical twist sense. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=helical%20twist%20sense" title="helical twist sense">helical twist sense</a>, <a href="https://publications.waset.org/abstracts/search?q=liquid%20crystals" title=" liquid crystals"> liquid crystals</a>, <a href="https://publications.waset.org/abstracts/search?q=nuclear%20magnetic%20resonance%20spectroscopy" title=" nuclear magnetic resonance spectroscopy"> nuclear magnetic resonance spectroscopy</a>, <a href="https://publications.waset.org/abstracts/search?q=vibrational%20spectroscopy" title=" vibrational spectroscopy"> vibrational spectroscopy</a> </p> <a href="https://publications.waset.org/abstracts/95848/the-inversion-of-helical-twist-sense-in-liquid-crystal-by-spectroscopy-methods" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/95848.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">282</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">122</span> Design of Tube Expanders with Groove Shapes to Reduce Deformation of Tube Inner Grooves in Copper Tube Expansion</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=I.%20Sin">I. Sin</a>, <a href="https://publications.waset.org/abstracts/search?q=H.%20Kim"> H. Kim</a>, <a href="https://publications.waset.org/abstracts/search?q=S.%20Park"> S. Park</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Fin-tube heat exchangers have grooves inside tubes to improve heat exchange performance. However, during the tube expansion process, heat exchange efficiency is decreased due to large deformation of tube inner grooves. Therefore, the objective of this study is to design a tube expander with groove shapes on its outer surface to minimize deformation of the inner grooves in copper tube expansion for fin-tube heat exchangers. In order to achieve this goal, first, we have tried to calculate tube inner groove deformation by the currently used tube expander without groove shapes on its surface. The tube inner groove deformation was acquired by elastoplastic finite element analysis from the boundary conditions with one tube end fixed and friction between the tube and tube expander (friction coefficient: 0.15). The tube expansion process was simulated by inserting the tube expander into the tube with a speed of 90 mm/s. The analysis results showed that tube inner groove heights were decreased by approximately 8 % from 0.15 mm to 0.138 mm with stress concentrations observed at the groove end, consistent with experimental results. Based on the current results, we are trying to design a novel shape of the tube expander with grooves to further reduce deformation tube inner grooves in copper tube expansion. For this, we will select major design variables of tube expander groove shapes by conducting sensitivity analysis and then optimize the design variables using the Taguchi method. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=tube%20expansion" title="tube expansion">tube expansion</a>, <a href="https://publications.waset.org/abstracts/search?q=tube%20expander" title=" tube expander"> tube expander</a>, <a href="https://publications.waset.org/abstracts/search?q=heat%20exchanger" title=" heat exchanger"> heat exchanger</a>, <a href="https://publications.waset.org/abstracts/search?q=finite%20element" title=" finite element"> finite element</a> </p> <a href="https://publications.waset.org/abstracts/60394/design-of-tube-expanders-with-groove-shapes-to-reduce-deformation-of-tube-inner-grooves-in-copper-tube-expansion" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/60394.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">327</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">121</span> Behavior of Helical Piles as Foundation of Photovoltaic Panels in Tropical Soils</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Andrea%20J.%20Alarc%C3%B3n">Andrea J. Alarcón</a>, <a href="https://publications.waset.org/abstracts/search?q=Maxime%20Daulat"> Maxime Daulat</a>, <a href="https://publications.waset.org/abstracts/search?q=Raydel%20Lorenzo"> Raydel Lorenzo</a>, <a href="https://publications.waset.org/abstracts/search?q=Renato%20P.%20Da%20Cunha"> Renato P. Da Cunha</a>, <a href="https://publications.waset.org/abstracts/search?q=Pierre%20Breul"> Pierre Breul</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Brazil has increased the use of renewable energy during the last years. Due to its sunshine and large surface area, photovoltaic panels founded in helical piles have been used to produce solar energy. Since Brazilian territory is mainly cover by highly porous structured tropical soils, when the helical piles are installed this structure is broken and its soil properties are modified. Considering the special characteristics of these soils, helical foundations behavior must be extensively studied. The first objective of this work is to determine the most suitable method to estimate the tensile capacity of helical piles in tropical soils. The second objective is to simulate the behavior of these piles in tropical soil. To obtain the rupture to assess load-displacement curves and the ultimate load, also a numerical modelling using Plaxis software was conducted. Lastly, the ultimate load and the load-displacements curves are compared with experimental values to validate the implemented model. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=finite%20element" title="finite element">finite element</a>, <a href="https://publications.waset.org/abstracts/search?q=helical%20piles" title=" helical piles"> helical piles</a>, <a href="https://publications.waset.org/abstracts/search?q=modelling" title=" modelling"> modelling</a>, <a href="https://publications.waset.org/abstracts/search?q=tropical%20soil" title=" tropical soil"> tropical soil</a>, <a href="https://publications.waset.org/abstracts/search?q=uplift%20capacity" title=" uplift capacity"> uplift capacity</a> </p> <a href="https://publications.waset.org/abstracts/123444/behavior-of-helical-piles-as-foundation-of-photovoltaic-panels-in-tropical-soils" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/123444.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">173</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">120</span> Selective Excitation of Circular Helical Modes in Graded Index Fibers</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=S.%20Al-Sowayan">S. Al-Sowayan</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The impact of selective excitation of circular helical modes of graded-index fibers on its capacity is analyzed using a model for propagation delay variation with launch offset and angle that resulted from misalignment of source and fiber axis. Results show that promising technique to improve graded-index fiber capacities. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=fiber%20measurements" title="fiber measurements">fiber measurements</a>, <a href="https://publications.waset.org/abstracts/search?q=fiber%20optic" title=" fiber optic"> fiber optic</a>, <a href="https://publications.waset.org/abstracts/search?q=communications" title=" communications"> communications</a>, <a href="https://publications.waset.org/abstracts/search?q=circular%20helical%20modes" title=" circular helical modes"> circular helical modes</a> </p> <a href="https://publications.waset.org/abstracts/3070/selective-excitation-of-circular-helical-modes-in-graded-index-fibers" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/3070.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">789</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">119</span> Behavior of Laterally Loaded Multi-Helix Helical Piles Under Vertical Loading in Cohesive and Cohesionless Soils</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Mona%20Fawzy%20Aldaghma">Mona Fawzy Aldaghma</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Helical piles are gaining popularity as a viable deep foundation alternative due to their quick installation and multipurpose use in compression and tension. These piles are commonly used as foundations for constructions such as solar panels, wind turbines and offshore platforms. These structures typically transfer various combinations of loads to their helical-pile foundations, including axial and lateral loads. Further research is needed to determine the effects of loading patterns that may act on helical piles as compounds of axial compression and lateral stresses. Multi helical piles are used to increase the efficiency of these piles. In this study, it investigate the behavior of laterally loaded helical piles with multiple helices when subjected to vertical loading conditions in both cohesive and cohesionless soils. Two models of intermediate shaft rigidity are studied with either two or three helices. Additionally, the vertical loading conditions were altered between successive and simultaneous loading. The cohesionless soil is sand with medium density and the cohesive soil is clay with medium cohesion. The study will carried out with numerical analysis using PLAXIS 3D and will be verified by an experimental tests. The numerical simulations reveal that helical piles exhibit different behavior in cohesive soil compared to cohesionless soil. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=helical%20piles" title="helical piles">helical piles</a>, <a href="https://publications.waset.org/abstracts/search?q=multi-helix" title=" multi-helix"> multi-helix</a>, <a href="https://publications.waset.org/abstracts/search?q=numerical%20modeling" title=" numerical modeling"> numerical modeling</a>, <a href="https://publications.waset.org/abstracts/search?q=PLAXIS%203D" title=" PLAXIS 3D"> PLAXIS 3D</a>, <a href="https://publications.waset.org/abstracts/search?q=cohesive%20soil" title=" cohesive soil"> cohesive soil</a>, <a href="https://publications.waset.org/abstracts/search?q=cohesionless%20soil" title=" cohesionless soil"> cohesionless soil</a>, <a href="https://publications.waset.org/abstracts/search?q=experimental" title=" experimental"> experimental</a> </p> <a href="https://publications.waset.org/abstracts/189283/behavior-of-laterally-loaded-multi-helix-helical-piles-under-vertical-loading-in-cohesive-and-cohesionless-soils" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/189283.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">36</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">118</span> Performance Study of Scraped Surface Heat Exchanger with Helical Ribbons</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=S.%20Ali">S. Ali</a>, <a href="https://publications.waset.org/abstracts/search?q=M.%20Baccar"> M. Baccar</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this work, numerical simulations were carried out using a specific CFD code in order to study the performance of an innovative Scraped Surface Heat Exchanger (SSHE) with helical ribbons for Bingham fluids (threshold fluids). The resolution of three-dimensional form of the conservation equations (continuity, momentum and energy equations) was carried out basing on the finite volume method (FVM). After studying the effect of dimensionless numbers (axial Reynolds, rotational Reynolds and Oldroyd numbers) on the hydrodynamic and thermal behaviors within SSHE, a parametric study was developed, by varying the width of the helical ribbon, the clearance between the stator wall and the tip of the ribbon and the number of turns of the helical ribbon, in order to improve the heat transfer inside the exchanger. The effect of these geometrical numbers on the hydrodynamic and thermal behaviors was discussed. <p class="card-text"><strong>Keywords:</strong> <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=helical%20ribbons" title=" helical ribbons"> helical ribbons</a>, <a href="https://publications.waset.org/abstracts/search?q=hydrodynamic%20behavior" title=" hydrodynamic behavior"> hydrodynamic behavior</a>, <a href="https://publications.waset.org/abstracts/search?q=parametric%20study" title=" parametric study"> parametric study</a>, <a href="https://publications.waset.org/abstracts/search?q=SSHE" title=" SSHE"> SSHE</a>, <a href="https://publications.waset.org/abstracts/search?q=thermal%20behavior" title=" thermal behavior"> thermal behavior</a> </p> <a href="https://publications.waset.org/abstracts/59515/performance-study-of-scraped-surface-heat-exchanger-with-helical-ribbons" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/59515.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">214</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">117</span> Influence of Loading Pattern and Shaft Rigidity on Laterally Loaded Helical Piles in Cohesion-Less Soil</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Mohamed%20Hesham%20Hamdy%20Abdelmohsen">Mohamed Hesham Hamdy Abdelmohsen</a>, <a href="https://publications.waset.org/abstracts/search?q=Ahmed%20Shawky%20Abdul%20Aziz"> Ahmed Shawky Abdul Aziz</a>, <a href="https://publications.waset.org/abstracts/search?q=Mona%20Fawzy%20Al-Daghma"> Mona Fawzy Al-Daghma</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Helical piles are widely used as axially and laterally loaded deep foundations. Once they are required to resist bearing combined loads (BCLs), as axial compression and lateral thrust, different behaviour is expected, necessitating further investigation. The objective of the present article is to clarify the behaviour of a single helical pile of different shaft rigidity embedded in cohesion-less soil and subjected to simultaneous or successive loading patterns of BCLs. The study was first developed analytically and extended numerically. The numerical analysis was further verified through a laboratory experimental program on a set of helical pile models. The results indicate highly interactive effects of the studied parameters, but it is obviously confirmed that the pile performance increases with both the increase of shaft rigidity and the change of BCLs loading pattern from simultaneous to successive. However, it is noted that the increase of vertical load does not always enhance the lateral capacity but may cause a decrement in lateral capacity, as observed with helical piles of flexible shafts. This study provides insightful information for the design of helical piles in structures loaded by complex sequence of forces, wind turbines, and industrial shafts. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=helical%20pile" title="helical pile">helical pile</a>, <a href="https://publications.waset.org/abstracts/search?q=lateral%20loads" title=" lateral loads"> lateral loads</a>, <a href="https://publications.waset.org/abstracts/search?q=combined%20loads" title=" combined loads"> combined loads</a>, <a href="https://publications.waset.org/abstracts/search?q=cohesion-less%20soil" title=" cohesion-less soil"> cohesion-less soil</a>, <a href="https://publications.waset.org/abstracts/search?q=analytical" title=" analytical"> analytical</a>, <a href="https://publications.waset.org/abstracts/search?q=numerical" title=" numerical"> numerical</a> </p> <a href="https://publications.waset.org/abstracts/186412/influence-of-loading-pattern-and-shaft-rigidity-on-laterally-loaded-helical-piles-in-cohesion-less-soil" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/186412.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">64</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">116</span> Fouling Mitigation Using Helical Baffle Heat Exchangers and Comparative Analysis Using HTRI Xchanger Suite® Educational Software </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Kiran%20P.%20Chadayamuri">Kiran P. Chadayamuri</a>, <a href="https://publications.waset.org/abstracts/search?q=Saransh%20Bagdi"> Saransh Bagdi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Heat exchangers are devices used to transfer heat from one fluid to another via convection and conduction. The need for effective heat transfer has made their presence vital in hundreds of industries including petroleum refineries, petrochemical plants, fertiliser plants and pharmaceutical companies. Fouling has been one of the major problems hindering efficient transfer of thermal energy in heat exchangers. Several design changes have been coined for fighting fouling. A recent development involves using helical baffles in place of conventional segmented baffles in shell and tube heat exchangers. The aim of this paper is to understand the advantages of helical baffle exchangers, how they aid in fouling mitigation and its corresponding limitations. A comparative analysis was conducted between a helical baffle heat exchanger and a conventional segmented baffle heat exchanger using HTRI Xchanger Suite® Educational software and conclusions were drawn to study how the heat transfer process differs in the two cases. <p class="card-text"><strong>Keywords:</strong> <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=heat%20exchangers" title=" heat exchangers"> heat exchangers</a>, <a href="https://publications.waset.org/abstracts/search?q=fouling%20mitigation" title=" fouling mitigation"> fouling mitigation</a>, <a href="https://publications.waset.org/abstracts/search?q=helical%20baffles" title=" helical baffles"> helical baffles</a> </p> <a href="https://publications.waset.org/abstracts/49858/fouling-mitigation-using-helical-baffle-heat-exchangers-and-comparative-analysis-using-htri-xchanger-suite-educational-software" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/49858.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">328</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">115</span> The Impact of Combined Loading on Lateral Capacity and Group Efficiency of Helical Piles</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Hesham%20Hamdy%20Abdulmohsen">Hesham Hamdy Abdulmohsen</a>, <a href="https://publications.waset.org/abstracts/search?q=Ahmed%20Shawky%20Abdel%20Aziz"> Ahmed Shawky Abdel Aziz</a>, <a href="https://publications.waset.org/abstracts/search?q=Mona%20Fawzy%20Aldaghma"> Mona Fawzy Aldaghma</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Helical piles have gained significant attention as efficient alternatives for deep foundations due to their rapid installation process and dual functionality in compression and tension. They experience various combinations of axial and lateral loads. While extensive research has explored helical pile behavior under individual axial or lateral loads, the effects of combined axial compression and lateral loads still need further study. This paper compares experimental and numerical (PLAXIS-3D) results for vertical helical-pile groups under combined loads. The study aims to clarify the impact of key factors, including helix location and lateral load direction, on the lateral capacity of helical-pile groups and, consequently, their overall efficiency. The study concludes that the lateral capacity of the helical-pile group significantly depends on the helix location within the pile shaft length. Optimal lateral performance occurs when helices are positioned at a depth ratio of H/L = 0.4. Furthermore, rectangular plan distribution groups exhibit greater lateral capacity when subjected to lateral loads aligned with their long axis. The presence of vertical compression loading enhances the lateral capacity of the group, with the specific enhancement depending on the value of the vertical compression load, lateral load direction, and helix location. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=experimental" title="experimental">experimental</a>, <a href="https://publications.waset.org/abstracts/search?q=numerical%20model" title=" numerical model"> numerical model</a>, <a href="https://publications.waset.org/abstracts/search?q=lateral%20loading" title=" lateral loading"> lateral loading</a>, <a href="https://publications.waset.org/abstracts/search?q=group%20efficiency" title=" group efficiency"> group efficiency</a>, <a href="https://publications.waset.org/abstracts/search?q=helical%20piles" title=" helical piles"> helical piles</a> </p> <a href="https://publications.waset.org/abstracts/190044/the-impact-of-combined-loading-on-lateral-capacity-and-group-efficiency-of-helical-piles" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/190044.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">40</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">114</span> Effect of Elastic Modulus Varieties on Helical Pile Behavior in Sand </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Javad%20Shamsi%20Soosahab">Javad Shamsi Soosahab</a>, <a href="https://publications.waset.org/abstracts/search?q=Reza%20Ziaie%20Moayed"> Reza Ziaie Moayed</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The compressive and tensile bearing capacity of helical piles in sand is investigated by means of numerical modeling. The analyses are carried out using two-dimensional finite-element software, Optum G2. The load–displacement behavior under compression and tension is compared in different relative densities for constant and various elastic modulus. The criterion used to find the ultimate axial load is the load corresponding to 5% of the helical diameter. The results show that relative density of sand plays an essential role in the response of ultimate capacities towards various condition. Increase in elastic modulus with depth is found to play a relatively more significant role to the increase in ultimate compressive load capacities, however tension bearing capacity decreases. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=helical%20piles" title="helical piles">helical piles</a>, <a href="https://publications.waset.org/abstracts/search?q=Optum%20G2" title=" Optum G2"> Optum G2</a>, <a href="https://publications.waset.org/abstracts/search?q=relative%20density" title=" relative density"> relative density</a>, <a href="https://publications.waset.org/abstracts/search?q=constant%20and%20various%20elastic%20modulus" title=" constant and various elastic modulus"> constant and various elastic modulus</a> </p> <a href="https://publications.waset.org/abstracts/126420/effect-of-elastic-modulus-varieties-on-helical-pile-behavior-in-sand" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/126420.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">151</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">113</span> Wear Diagnosis of Diesel Engine Helical Gear</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Surjit%20Angra">Surjit Angra</a>, <a href="https://publications.waset.org/abstracts/search?q=Gajanan%20Rane"> Gajanan Rane</a>, <a href="https://publications.waset.org/abstracts/search?q=Vinod%20Kumar"> Vinod Kumar</a>, <a href="https://publications.waset.org/abstracts/search?q=Sushma%20Rani"> Sushma Rani</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents metallurgical investigation of failed helical gear of diesel engine gear box used in a car. The failure had occurred near the bottomland of the tooth spacing. The failed surface was studied under Scanning Electron Microscope (SEM) and also visually investigated. The images produced through SEM at various magnifications were studied. Detailed metallurgical study indicates that failure was due to foreign material inclusion which is a casting defect. Further study also revealed pitting, spalling and inter-granular fracture as the causes of gear failure. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=helical%20gear" title="helical gear">helical gear</a>, <a href="https://publications.waset.org/abstracts/search?q=scanning%20electron%20microscope" title=" scanning electron microscope"> scanning electron microscope</a>, <a href="https://publications.waset.org/abstracts/search?q=casting%20defect" title=" casting defect"> casting defect</a>, <a href="https://publications.waset.org/abstracts/search?q=pitting" title=" pitting"> pitting</a> </p> <a href="https://publications.waset.org/abstracts/49719/wear-diagnosis-of-diesel-engine-helical-gear" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/49719.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">112</span> Effect of Helical Flow on Separation Delay in the Aortic Arch for Different Mechanical Heart Valve Prostheses by Time-Resolved Particle Image Velocimetry </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Qianhui%20Li">Qianhui Li</a>, <a href="https://publications.waset.org/abstracts/search?q=Christoph%20H.%20Bruecker"> Christoph H. Bruecker</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Atherosclerotic plaques are typically found where flow separation and variations of shear stress occur. Although helical flow patterns and flow separations have been recorded in the aorta, their relation has not been clearly clarified and especially in the condition of artificial heart valve prostheses. Therefore, an experimental study is performed to investigate the hemodynamic performance of different mechanical heart valves (MHVs), i.e. the SJM Regent bileaflet mechanical heart valve (BMHV) and the Lapeyre-Triflo FURTIVA trileaflet mechanical heart valve (TMHV), in a transparent model of the human aorta under a physiological pulsatile right-hand helical flow condition. A typical systolic flow profile is applied in the pulse-duplicator to generate a physiological pulsatile flow which thereafter flows past an axial turbine blade structure to imitate the right-hand helical flow induced in the left ventricle. High-speed particle image velocimetry (PIV) measurements are used to map the flow evolution. A circular open orifice nozzle inserted in the valve plane as the reference configuration initially replaces the valve under investigation to understand the hemodynamic effects of the entered helical flow structure on the flow evolution in the aortic arch. Flow field analysis of the open orifice nozzle configuration illuminates the helical flow effectively delays the flow separation at the inner radius wall of the aortic arch. The comparison of the flow evolution for different MHVs shows that the BMHV works like a flow straightener which re-configures the helical flow pattern into three parallel jets (two side-orifice jets and the central orifice jet) while the TMHV preserves the helical flow structure and therefore prevent the flow separation at the inner radius wall of the aortic arch. Therefore the TMHV is of better hemodynamic performance and reduces the pressure loss. <p class="card-text"><strong>Keywords:</strong> <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=helical%20aortic%20flow" title=" helical aortic flow"> helical aortic flow</a>, <a href="https://publications.waset.org/abstracts/search?q=mechanical%20heart%20valve" title=" mechanical heart valve"> mechanical heart valve</a>, <a href="https://publications.waset.org/abstracts/search?q=particle%20image%20velocimetry" title=" particle image velocimetry"> particle image velocimetry</a> </p> <a href="https://publications.waset.org/abstracts/110757/effect-of-helical-flow-on-separation-delay-in-the-aortic-arch-for-different-mechanical-heart-valve-prostheses-by-time-resolved-particle-image-velocimetry" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/110757.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">174</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">111</span> Comparison of Spiral Circular Coil and Helical Coil Structures for Wireless Power Transfer System</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Zhang%20Kehan">Zhang Kehan</a>, <a href="https://publications.waset.org/abstracts/search?q=Du%20Luona"> Du Luona</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Wireless power transfer (WPT) systems have been widely investigated for advantages of convenience and safety compared to traditional plug-in charging systems. The research contents include impedance matching, circuit topology, transfer distance et al. for improving the efficiency of WPT system, which is a decisive factor in the practical application. What is more, coil structures such as spiral circular coil and helical coil with variable distance between two turns also have indispensable effects on the efficiency of WPT systems. This paper compares the efficiency of WPT systems utilizing spiral or helical coil with variable distance between two turns, and experimental results show that efficiency of spiral circular coil with an optimum distance between two turns is the highest. According to efficiency formula of resonant WPT system with series-series topology, we introduce M²/R₋₁ to measure the efficiency of spiral circular coil and helical coil WPT system. If the distance between two turns s is too close, proximity effect theory shows that the induced current in the conductor, caused by a variable flux created by the current flows in the skin of vicinity conductor, is the opposite direction of source current and has assignable impart on coil resistance. Thus in two coil structures, s affects coil resistance. At the same time, when the distance between primary and secondary coils is not variable, s can also make the influence on M to some degrees. The aforementioned study proves that s plays an indispensable role in changing M²/R₋₁ and then can be adjusted to find the optimum value with which WPT system achieves the highest efficiency. In actual application situations of WPT systems especially in underwater vehicles, miniaturization is one vital issue in designing WPT system structures. Limited by system size, the largest external radius of spiral circular coil is 100 mm, and the largest height of helical coil is 40 mm. In other words, the turn of coil N changes with s. In spiral circular and helical structures, the distance between each two turns in secondary coil is set as a constant value 1 mm to guarantee that the R2 is not variable. Based on the analysis above, we set up spiral circular coil and helical coil model using COMSOL to analyze the value of M²/R₋₁ when the distance between each two turns in primary coil sp varies from 0 mm to 10 mm. In the two structure models, the distance between primary and secondary coils is 50 mm and wire diameter is chosen as 1.5 mm. The turn of coil in secondary coil are 27 in helical coil model and 20 in spiral circular coil model. The best value of s in helical coil structure and spiral circular coil structure are 1 mm and 2 mm respectively, in which the value of M²/R₋₁ is the largest. It is obviously to select spiral circular coil as the first choice to design the WPT system for that the value of M²/R₋₁ in spiral circular coil is larger than that in helical coil under the same condition. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=distance%20between%20two%20turns" title="distance between two turns">distance between two turns</a>, <a href="https://publications.waset.org/abstracts/search?q=helical%20coil" title=" helical coil"> helical coil</a>, <a href="https://publications.waset.org/abstracts/search?q=spiral%20circular%20coil" title=" spiral circular coil"> spiral circular coil</a>, <a href="https://publications.waset.org/abstracts/search?q=wireless%20power%20transfer" title=" wireless power transfer"> wireless power transfer</a> </p> <a href="https://publications.waset.org/abstracts/55432/comparison-of-spiral-circular-coil-and-helical-coil-structures-for-wireless-power-transfer-system" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/55432.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">345</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">110</span> Movable Airfoil Arm (MAA) and Ducting Effect to Increase the Efficiency of a Helical Turbine</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Abdi%20Ismail">Abdi Ismail</a>, <a href="https://publications.waset.org/abstracts/search?q=Zain%20Amarta"> Zain Amarta</a>, <a href="https://publications.waset.org/abstracts/search?q=Riza%20Rifaldy%20Argaputra"> Riza Rifaldy Argaputra</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The Helical Turbine has the highest efficiency in comparison with the other hydrokinetic turbines. However, the potential of the Helical Turbine efficiency can be further improved so that the kinetic energy of a water current can be converted into mechanical energy as much as possible. This paper explains the effects by adding a Movable Airfoil Arm (MAA) and ducting on a Helical Turbine. The first research conducted an analysis of the efficiency comparison between a Plate Arm Helical Turbine (PAHT) versus a Movable Arm Helical Turbine Airfoil (MAAHT) at various water current velocities. The first step is manufacturing a PAHT and MAAHT. The PAHT and MAAHT has these specifications (as a fixed variable): 80 cm in diameter, a height of 88 cm, 3 blades, NACA 0018 blade profile, a 10 cm blade chord and a 60o inclination angle. The MAAHT uses a NACA 0012 airfoil arm that can move downward 20o, the PAHT uses a 5 mm plate arm. At the current velocity of 0.8, 0.85 and 0.9 m/s, the PAHT respectively generates a mechanical power of 92, 117 and 91 watts (a consecutive efficiency of 16%, 17% and 11%). At the same current velocity variation, the MAAHT respectively generates 74, 60 and 43 watts (a consecutive efficiency of 13%, 9% and 5%). Therefore, PAHT has a better performance than the MAAHT. Using analysis from CFD (Computational Fluid Dynamics), the drag force of MAA is greater than the one generated by the plate arm. By using CFD analysis, the drag force that occurs on the MAA is more dominant than the lift force, therefore the MAA can be called a drag device, whereas the lift force that occurs on the helical blade is more dominant than the drag force, therefore it can be called a lift device. Thus, the lift device cannot be combined with the drag device, because the drag device will become a hindrance to the lift device rotation. The second research conducted an analysis of the efficiency comparison between a Ducted Helical Turbine (DHT) versus a Helical Turbine (HT) through experimental studies. The first step is manufacturing the DHT and HT. The Helical turbine specifications (as a fixed variable) are: 40 cm in diameter, a height of 88 cm, 3 blades, NACA 0018 blade profile, 10 cm blade chord and a 60o inclination angle. At the current speed of 0.7, 0.8, 0.9 and 1.1 m/s, the HT respectively generates a mechanical power of 72, 85, 93 and 98 watts (a consecutive efficiency of 38%, 30%, 23% and 13%). At the same current speed variation, the DHT generates a mechanical power of 82, 98, 110 and 134 watts (a consecutive efficiency of 43%, 34%, 27% and 18%), respectively. The usage of ducting causes the water current speed around the turbine to increase. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=hydrokinetic%20turbine" title="hydrokinetic turbine">hydrokinetic turbine</a>, <a href="https://publications.waset.org/abstracts/search?q=helical%20turbine" title=" helical turbine"> helical turbine</a>, <a href="https://publications.waset.org/abstracts/search?q=movable%20airfoil%20arm" title=" movable airfoil arm"> movable airfoil arm</a>, <a href="https://publications.waset.org/abstracts/search?q=ducting" title=" ducting"> ducting</a> </p> <a href="https://publications.waset.org/abstracts/37067/movable-airfoil-arm-maa-and-ducting-effect-to-increase-the-efficiency-of-a-helical-turbine" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/37067.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">371</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">109</span> Impedance Matching of Axial Mode Helical Antennas</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Hossein%20Mardani">Hossein Mardani</a>, <a href="https://publications.waset.org/abstracts/search?q=Neil%20Buchanan"> Neil Buchanan</a>, <a href="https://publications.waset.org/abstracts/search?q=Robert%20Cahill"> Robert Cahill</a>, <a href="https://publications.waset.org/abstracts/search?q=Vincent%20Fusco"> Vincent Fusco</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper, we study the input impedance characteristics of axial mode helical antennas to find an effective way for matching it to 50 Ω. The study is done on the important matching parameters such as like wire diameter and helix to the ground plane gap. It is intended that these parameters control the matching without detrimentally affecting the radiation pattern. Using transmission line theory, a simple broadband technique is proposed, which is applicable for perfect matching of antennas with similar design parameters. We provide design curves to help to choose the proper dimensions of the matching section based on the antenna’s unmatched input impedance. Finally, using the proposed technique, a 4-turn axial mode helix is designed at 2.5 GHz center frequency and the measurement results of the manufactured antenna will be included. This parametric study gives a good insight into the input impedance characteristics of axial mode helical antennas and the proposed impedance matching approach provides a simple, useful method for matching these types of antennas. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=antenna" title="antenna">antenna</a>, <a href="https://publications.waset.org/abstracts/search?q=helix" title=" helix"> helix</a>, <a href="https://publications.waset.org/abstracts/search?q=helical" title=" helical"> helical</a>, <a href="https://publications.waset.org/abstracts/search?q=axial%20mode" title=" axial mode"> axial mode</a>, <a href="https://publications.waset.org/abstracts/search?q=wireless%20power%20transfer" title=" wireless power transfer"> wireless power transfer</a>, <a href="https://publications.waset.org/abstracts/search?q=impedance%20matching" title=" impedance matching"> impedance matching</a> </p> <a href="https://publications.waset.org/abstracts/134308/impedance-matching-of-axial-mode-helical-antennas" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/134308.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">312</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">108</span> Lateral Capacity of Helical-Pile Groups Subjected to Bearing Combined Loads</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Hesham%20Hamdy%20Abdelmohsen">Hesham Hamdy Abdelmohsen</a>, <a href="https://publications.waset.org/abstracts/search?q=Ahmed%20Shawky%20Abdul%20Azizb"> Ahmed Shawky Abdul Azizb</a>, <a href="https://publications.waset.org/abstracts/search?q=Mona%20Fawzy%20Aldaghma"> Mona Fawzy Aldaghma</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Helical piles have earned considerable attention as an effective deep foundation alternative due to their rapid installation process and their dual purpose in compression and tension. These piles find common uses as foundations for structures like solar panels, wind turbines, offshore platforms, and some kinds of retaining walls. These structures usually transfer different combinations of loads to their helical-pile foundations in the form of axial and lateral loads. Extensive research has been conducted to investigate and understand the behavior of these piles under the influence of either axial or lateral loads. However, the impacts of loading patterns that may act on the helical piles as combinations of axial compression and lateral loads still need more efforts of research work. This paper presents the results of an experimental (Lab tests) and numerical (PLAXIS-3D) study performed on vertical helical-pile groups under the action of combined loads as axial compression (bearing loads), acting successively with lateral (horizontal) loads. The study aims to clarify the effects of key factors, like helix location and direction of lateral load, on the lateral capacity of helical-pile groups and, consequently, on group efficiency. Besides the variation of helix location and lateral load direction, three patterns of successive bearing combined loads were considered, in which the axial vertical compression load was either zero, V1 or V2, whereas the lateral horizontal loads were varied under each vertical compression load. The study concluded that the lateral capacity of the helical-pile group is significantly affected by helix location within the length of the pile shaft. The optimal lateral performance is achieved with helices at a depth ratio of H/L = 0.4. Furthermore, groups of rectangular plan distribution exhibit greater lateral capacity if subjected to lateral horizontal load in the direction of its long axis. Additionally, the research emphasizes that the presence of vertical compression loading can enhance the lateral capacity of the group. This enhancement depends on the value of the vertical compression load, lateral load direction, and helix location, which highlights the complex interaction effect of these factors on the efficiency of helical-pile groups. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=helical%20piles" title="helical piles">helical piles</a>, <a href="https://publications.waset.org/abstracts/search?q=experimental" title=" experimental"> experimental</a>, <a href="https://publications.waset.org/abstracts/search?q=numerical" title=" numerical"> numerical</a>, <a href="https://publications.waset.org/abstracts/search?q=lateral%20loading" title=" lateral loading"> lateral loading</a>, <a href="https://publications.waset.org/abstracts/search?q=group%20efficiency" title=" group efficiency"> group efficiency</a> </p> <a href="https://publications.waset.org/abstracts/189201/lateral-capacity-of-helical-pile-groups-subjected-to-bearing-combined-loads" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/189201.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">107</span> Nonlinear Dynamic Response of Helical Gear with Torque-Limiter</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ahmed%20Guerine">Ahmed Guerine</a>, <a href="https://publications.waset.org/abstracts/search?q=Ali%20El%20Hafidi"> Ali El Hafidi</a>, <a href="https://publications.waset.org/abstracts/search?q=Bruno%20Martin"> Bruno Martin</a>, <a href="https://publications.waset.org/abstracts/search?q=Philippe%20Leclaire"> Philippe Leclaire</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper investigates the nonlinear dynamic response of a mechanical torque limiter which is used to protect drive parts from overload (helical transmission gears). The system is driven by four excitations: two external excitations (aerodynamics torque and force) and two internal excitations (two mesh stiffness fluctuations). In this work, we develop a dynamic model with lumped components and 28 degrees of freedom. We use the Runge Kutta step-by-step time integration numerical algorithm to solve the equations of motion obtained by Lagrange formalism. The numerical results have allowed us to identify the sources of vibration in the wind turbine. Also, they are useful to help the designer to make the right design and correctly choose the times for maintenance. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=two-stage%20helical%20gear" title="two-stage helical gear">two-stage helical gear</a>, <a href="https://publications.waset.org/abstracts/search?q=lumped%20model" title=" lumped model"> lumped model</a>, <a href="https://publications.waset.org/abstracts/search?q=dynamic%20response" title=" dynamic response"> dynamic response</a>, <a href="https://publications.waset.org/abstracts/search?q=torque-limiter" title=" torque-limiter"> torque-limiter</a> </p> <a href="https://publications.waset.org/abstracts/142306/nonlinear-dynamic-response-of-helical-gear-with-torque-limiter" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/142306.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">353</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">106</span> Numerical investigation of Hydrodynamic and Parietal Heat Transfer to Bingham Fluid Agitated in a Vessel by Helical Ribbon Impeller</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Mounir%20Baccar">Mounir Baccar</a>, <a href="https://publications.waset.org/abstracts/search?q=Amel%20Gammoudi"> Amel Gammoudi</a>, <a href="https://publications.waset.org/abstracts/search?q=Abdelhak%20Ayadi"> Abdelhak Ayadi</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The efficient mixing of highly viscous fluids is required for many industries such as food, polymers or paints production. The homogeneity is a challenging operation for this fluids type since they operate at low Reynolds number to reduce the required power of the used impellers. Particularly, close-clearance impellers, mainly helical ribbons, are chosen for highly viscous fluids agitated in laminar regime which is currently heated through vessel wall. Indeed, they are characterized by high shear strains closer to the vessel wall, which causes a disturbing thermal boundary layer and ensures the homogenization of the bulk volume by axial and radial vortices. The hydrodynamic and thermal behaviors of Newtonian fluids in vessels agitated by helical ribbon impellers, has been mostly studied by many researchers. However, rarely researchers investigated numerically the agitation of yield stress fluid by means of helical ribbon impellers. This paper aims to study the effect of the Double Helical Ribbon (DHR) stirrers on both the hydrodynamic and the thermal behaviors of yield stress fluids treated in a cylindrical vessel by means of numerical simulation approach. For this purpose, continuity, momentum, and thermal equations were solved by means of 3D finite volume technique. The effect of Oldroyd (Od) and Reynolds (Re) numbers on the power (Po) and Nusselt (Nu) numbers for the mentioned stirrer type have been studied. Also, the velocity and thermal fields, the dissipation function and the apparent viscosity have been presented in different (r-z) and (r-θ) planes. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Bingham%20fluid" title="Bingham fluid">Bingham fluid</a>, <a href="https://publications.waset.org/abstracts/search?q=Hydrodynamic%20and%20thermal%20behavior" title=" Hydrodynamic and thermal behavior"> Hydrodynamic and thermal behavior</a>, <a href="https://publications.waset.org/abstracts/search?q=helical%20ribbon" title=" helical ribbon"> helical ribbon</a>, <a href="https://publications.waset.org/abstracts/search?q=mixing" title=" mixing"> mixing</a>, <a href="https://publications.waset.org/abstracts/search?q=numerical%20modelling" title=" numerical modelling"> numerical modelling</a> </p> <a href="https://publications.waset.org/abstracts/57711/numerical-investigation-of-hydrodynamic-and-parietal-heat-transfer-to-bingham-fluid-agitated-in-a-vessel-by-helical-ribbon-impeller" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/57711.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">306</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">105</span> Evaluation of the Power Generation Effect Obtained by Inserting a Piezoelectric Sheet in the Backlash Clearance of a Circular Arc Helical Gear</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Barenten%20Suciu">Barenten Suciu</a>, <a href="https://publications.waset.org/abstracts/search?q=Yuya%20Nakamoto"> Yuya Nakamoto</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Power generation effect, obtained by inserting a piezo- electric sheet in the backlash clearance of a circular arc helical gear, is evaluated. Such type of screw gear is preferred since, in comparison with the involute tooth profile, the circular arc profile leads to reduced stress-concentration effects, and improved life of the piezoelectric film. Firstly, geometry of the circular arc helical gear, and properties of the piezoelectric sheet are presented. Then, description of the test-rig, consisted of a right-hand thread gear meshing with a left-hand thread gear, and the voltage measurement procedure are given. After creating the tridimensional (3D) model of the meshing gears in SolidWorks, they are 3D-printed in acrylonitrile butadiene styrene (ABS) resin. Variation of the generated voltage versus time, during a meshing cycle of the circular arc helical gear, is measured for various values of the center distance. Then, the change of the maximal, minimal, and peak-to-peak voltage versus the center distance is illustrated. Optimal center distance of the gear, to achieve voltage maximization, is found and its significance is discussed. Such results prove that the contact pressure of the meshing gears can be measured, and also, the electrical power can be generated by employing the proposed technique. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=circular%20arc%20helical%20gear" title="circular arc helical gear">circular arc helical gear</a>, <a href="https://publications.waset.org/abstracts/search?q=contact%20problem" title=" contact problem"> contact problem</a>, <a href="https://publications.waset.org/abstracts/search?q=optimal%20center%20distance" title=" optimal center distance"> optimal center distance</a>, <a href="https://publications.waset.org/abstracts/search?q=piezoelectric%20sheet" title=" piezoelectric sheet"> piezoelectric sheet</a>, <a href="https://publications.waset.org/abstracts/search?q=power%20generation" title=" power generation"> power generation</a> </p> <a href="https://publications.waset.org/abstracts/112480/evaluation-of-the-power-generation-effect-obtained-by-inserting-a-piezoelectric-sheet-in-the-backlash-clearance-of-a-circular-arc-helical-gear" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/112480.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">104</span> Simulation of Die Casting Process in an Industrial Helical Gearbox Flange Die</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Mehdi%20Modabberifar">Mehdi Modabberifar</a>, <a href="https://publications.waset.org/abstracts/search?q=Behrouz%20Raad"> Behrouz Raad</a>, <a href="https://publications.waset.org/abstracts/search?q=Bahman%20Mirzakhani"> Bahman Mirzakhani</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Flanges are widely used for connecting valves, pipes and other industrial devices such as gearboxes. Method of producing a flange has a considerable impact on the manner of their involvement with the industrial engines and gearboxes. By Using die casting instead of sand casting and machining for manufacturing flanges, production speed and dimensional accuracy of the parts increases. Also, in die casting, obtained dimensions are close to final dimensions and hence the need for machining flanges after die casting process decreases which makes a significant savings in raw materials and improves the mechanical properties of flanges. In this paper, a typical die of an industrial helical gearbox flange (size ISO 50) was designed and die casting process for producing this type of flange was simulated using ProCAST software. The results of simulation were used for optimizing die design. Finally, using the results of the analysis, optimized die was built. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=die%20casting" title="die casting">die casting</a>, <a href="https://publications.waset.org/abstracts/search?q=finite%20element" title=" finite element"> finite element</a>, <a href="https://publications.waset.org/abstracts/search?q=flange" title=" flange"> flange</a>, <a href="https://publications.waset.org/abstracts/search?q=helical%20gearbox" title=" helical gearbox"> helical gearbox</a> </p> <a href="https://publications.waset.org/abstracts/7659/simulation-of-die-casting-process-in-an-industrial-helical-gearbox-flange-die" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/7659.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">367</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">103</span> Vertical Uplift Capacity of a Group of Equally Spaced Helical Screw Anchors in Sand</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Sanjeev%20Mukherjee">Sanjeev Mukherjee</a>, <a href="https://publications.waset.org/abstracts/search?q=Satyendra%20Mittal"> Satyendra Mittal</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents the experimental investigations on the behaviour of a group of single, double and triple helical screw anchors embedded vertically at the same level in sand. The tests were carried out on one, two, three and four numbers of anchors in sand for different depths of embedment keeping shallow and deep mode of behaviour in mind. The testing program included 48 tests conducted on three model anchors installed in sand whose density kept constant throughout the tests. It was observed that the ultimate pullout load varied significantly with the installation depth of the anchor and the number of anchors. The apparent coefficient of friction (f*) between anchor and soil was also calculated based on the test results. It was found that the apparent coefficient of friction varies between 1.02 and 4.76 for 1, 2, 3, and 4 numbers of single, double and triple helical screw anchors. Plate load tests conducted on model soil showed that the value of ф increases from 35o for virgin soil to 48o for soil with four double screw helical anchors. The graphs of ultimate pullout capacity of a group of two, three and four no. of anchors with respect to one anchor were plotted and design equations have been proposed correlating them. Based on these findings, it has been concluded that the load-displacement relationships for all groups can be reduced to a common curve. A 3-D finite element model, PLAXIS, was used to confirm the results obtained from laboratory tests and the agreement is excellent. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=apparent%20coefficient%20of%20friction" title="apparent coefficient of friction">apparent coefficient of friction</a>, <a href="https://publications.waset.org/abstracts/search?q=helical%20screw%20anchor" title=" helical screw anchor"> helical screw anchor</a>, <a href="https://publications.waset.org/abstracts/search?q=installation%20depth" title=" installation depth"> installation depth</a>, <a href="https://publications.waset.org/abstracts/search?q=plate%20load%20test" title=" plate load test"> plate load test</a> </p> <a href="https://publications.waset.org/abstracts/41298/vertical-uplift-capacity-of-a-group-of-equally-spaced-helical-screw-anchors-in-sand" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/41298.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">555</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=helical%20grooves&page=2">2</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=helical%20grooves&page=3">3</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=helical%20grooves&page=4">4</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=helical%20grooves&page=5">5</a></li> <li class="page-item"><a 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