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weir</title> <meta name="description" content="Search results for: trapezoidal weir"> <meta name="keywords" content="trapezoidal weir"> <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="trapezoidal weir"> <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> 92</div> </div> </div> </div> <h1 class="mt-3 mb-3 text-center" style="font-size:1.6rem;">Search results for: trapezoidal weir</h1> <div class="card paper-listing mb-3 mt-3"> <h5 class="card-header" style="font-size:.9rem"><span class="badge badge-info">92</span> Predicting Trapezoidal Weir Discharge Coefficient Using Evolutionary Algorithm</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=K.%20Roushanger">K. Roushanger</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Soleymanzadeh"> A. Soleymanzadeh</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Weirs are structures often used in irrigation techniques, sewer networks and flood protection. However, the hydraulic behavior of this type of weir is complex and difficult to predict accurately. An accurate flow prediction over a weir mainly depends on the proper estimation of discharge coefficient. In this study, the Genetic Expression Programming (GEP) approach was used for predicting trapezoidal and rectangular sharp-crested side weirs discharge coefficient. Three different performance indexes are used as comparing criteria for the evaluation of the model’s performances. The obtained results approved capability of GEP in prediction of trapezoidal and rectangular side weirs discharge coefficient. The results also revealed the influence of downstream Froude number for trapezoidal weir and upstream Froude number for rectangular weir in prediction of the discharge coefficient for both of side weirs. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=discharge%20coefficient" title="discharge coefficient">discharge coefficient</a>, <a href="https://publications.waset.org/abstracts/search?q=genetic%20expression%20programming" title=" genetic expression programming"> genetic expression programming</a>, <a href="https://publications.waset.org/abstracts/search?q=trapezoidal%20weir" title=" trapezoidal weir"> trapezoidal weir</a> </p> <a href="https://publications.waset.org/abstracts/61052/predicting-trapezoidal-weir-discharge-coefficient-using-evolutionary-algorithm" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/61052.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">387</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">91</span> Estimation of Coefficient of Discharge of Side Trapezoidal Labyrinth Weir Using Group Method of Data Handling Technique</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=M.%20A.%20Ansari">M. A. Ansari</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Hussain"> A. Hussain</a>, <a href="https://publications.waset.org/abstracts/search?q=A.%20Uddin"> A. Uddin</a> </p> <p class="card-text"><strong>Abstract:</strong></p> A side weir is a flow diversion structure provided in the side wall of a channel to divert water from the main channel to a branch channel. The trapezoidal labyrinth weir is a special type of weir in which crest length of the weir is increased to pass higher discharge. Experimental and numerical studies related to the coefficient of discharge of trapezoidal labyrinth weir in an open channel have been presented in the present study. Group Method of Data Handling (GMDH) with the transfer function of quadratic polynomial has been used to predict the coefficient of discharge for the side trapezoidal labyrinth weir. A new model is developed for coefficient of discharge of labyrinth weir by regression method. Generalized models for predicting the coefficient of discharge for labyrinth weir using Group Method of Data Handling (GMDH) network have also been developed. The prediction based on GMDH model is more satisfactory than those given by traditional regression equations. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=discharge%20coefficient" title="discharge coefficient">discharge coefficient</a>, <a href="https://publications.waset.org/abstracts/search?q=group%20method%20of%20data%20handling" title=" group method of data handling"> group method of data handling</a>, <a href="https://publications.waset.org/abstracts/search?q=open%20channel" title=" open channel"> open channel</a>, <a href="https://publications.waset.org/abstracts/search?q=side%20labyrinth%20weir" title=" side labyrinth weir"> side labyrinth weir</a> </p> <a href="https://publications.waset.org/abstracts/115809/estimation-of-coefficient-of-discharge-of-side-trapezoidal-labyrinth-weir-using-group-method-of-data-handling-technique" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/115809.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">160</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">90</span> General Formula for Water Surface Profile over Side Weir in the Combined, Trapezoidal and Exponential, Channels</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Abdulrahman%20Abdulrahman">Abdulrahman Abdulrahman</a> </p> <p class="card-text"><strong>Abstract:</strong></p> A side weir is a hydraulic structure set into the side of a channel. This structure is used for water level control in channels, to divert flow from a main channel into a side channel when the water level in the main channel exceeds a specific limit and as storm overflows from urban sewerage system. Computation of water surface over the side weirs is essential to determine the flow rate of the side weir. Analytical solutions for water surface profile along rectangular side weir are available only for the special cases of rectangular and trapezoidal channels considering constant specific energy. In this paper, a rectangular side weir located in a combined (trapezoidal with exponential) channel was considered. Expanding binominal series of integer and fraction powers and the using of reduction formula of cosine function integrals, a general analytical formula was obtained for water surface profile along a side weir in a combined (trapezoidal with exponential) channel. Since triangular, rectangular, trapezoidal and parabolic cross-sections are special cases of the combined cross section, the derived formula, is applicable to triangular, rectangular, trapezoidal cross-sections as analytical solution and semi-analytical solution to parabolic cross-section with maximum relative error smaller than 0.76%. The proposed solution should be a useful engineering tool for the evaluation and design of side weirs in open channel. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=analytical%20solution" title="analytical solution">analytical solution</a>, <a href="https://publications.waset.org/abstracts/search?q=combined%20channel" title=" combined channel"> combined channel</a>, <a href="https://publications.waset.org/abstracts/search?q=exponential%20channel" title=" exponential channel"> exponential channel</a>, <a href="https://publications.waset.org/abstracts/search?q=side%20weirs" title=" side weirs"> side weirs</a>, <a href="https://publications.waset.org/abstracts/search?q=trapezoidal%20channel" title=" trapezoidal channel"> trapezoidal channel</a>, <a href="https://publications.waset.org/abstracts/search?q=water%20surface%20profile" title=" water surface profile"> water surface profile</a> </p> <a href="https://publications.waset.org/abstracts/59960/general-formula-for-water-surface-profile-over-side-weir-in-the-combined-trapezoidal-and-exponential-channels" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/59960.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">237</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">89</span> Performance Evaluation of a Piano Key Weir</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=M.%20Shaheer%20Ali">M. Shaheer Ali</a>, <a href="https://publications.waset.org/abstracts/search?q=Talib%20Mansoor"> Talib Mansoor</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The Piano Key Weir (PKW) is a particular shape of labyrinth weir, using up- and/or downstream overhangs. The horizontal rectangular labyrinth shape allows to multiply the crest length for a given weir width. With the increasing demand of power, it is becoming greatly essential to increase the storage capacity of existing dams without neglecting their safety. The present aims at comparing the performance of piano key weirs in respect to the normal sharp-crested weirs. The discharge v/s head data for the piano key weir and normal sharp-crested weir obtained from the experimental study were compared and analysed using regression analysis. Piano key weir was found to perform doubly w.r.t a normal weir. The flow profiles show the parabolic nature of flow and the nappe interference in the inlet keys. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=crest%20length" title="crest length">crest length</a>, <a href="https://publications.waset.org/abstracts/search?q=flow%20profile" title=" flow profile"> flow profile</a>, <a href="https://publications.waset.org/abstracts/search?q=labyrinth%20weir" title=" labyrinth weir"> labyrinth weir</a>, <a href="https://publications.waset.org/abstracts/search?q=normal%20weir" title=" normal weir"> normal weir</a>, <a href="https://publications.waset.org/abstracts/search?q=nappe%20interference" title=" nappe interference"> nappe interference</a>, <a href="https://publications.waset.org/abstracts/search?q=overhangs" title=" overhangs"> overhangs</a>, <a href="https://publications.waset.org/abstracts/search?q=piano%20key%20weir" title=" piano key weir"> piano key weir</a> </p> <a href="https://publications.waset.org/abstracts/24326/performance-evaluation-of-a-piano-key-weir" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/24326.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">294</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">88</span> Investigation of Flow Characteristics of Trapezoidal Side Weir in Rectangular Channel for Subcritical Flow</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Malkhan%20Thakur">Malkhan Thakur</a>, <a href="https://publications.waset.org/abstracts/search?q=P.%20Deepak%20Kumar"> P. Deepak Kumar</a>, <a href="https://publications.waset.org/abstracts/search?q=P.%20K.%20S.%20Dikshit"> P. K. S. Dikshit</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In recent years, the hydraulic behavior of side weirs has been the subject of many investigations. Most of the studies have been in connection with specific problems and have involved models. This is perhaps understandable, since a generalized treatment is made difficult by the large number of possible variables to be used to define the problem. A variety of empirical head discharge relationships have been suggested for side weirs. These empirical approaches failed to adequately consider the actual situation, and produced equations applicable only in circumstances virtually identical to those of the experiment. The present investigation is targeted to study to a greater depth the effect of different trapezium angles of a trapezoidal side weir and study of water surface profile in spatially varied flow with decreasing discharge maintaining the main channel flow subcritical. On the basis of experiment, the relationship between upstream Froude number and coefficient of discharge has been established. All the characteristics of spatially varied flow with decreasing discharge have been studied and subsequently formulated. The scope of the present investigation has been basically limited to a one-dimensional model of flow for the purpose of analysis. A formulation has been derived using the theoretical concept of constant specific energy. Coefficient of discharge has been calculated and experimental results were presented. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=weirs" title="weirs">weirs</a>, <a href="https://publications.waset.org/abstracts/search?q=subcritical%20flow" title=" subcritical flow"> subcritical flow</a>, <a href="https://publications.waset.org/abstracts/search?q=rectangular%20channel" title=" rectangular channel"> rectangular channel</a>, <a href="https://publications.waset.org/abstracts/search?q=trapezoidal%20side%20weir" title=" trapezoidal side weir"> trapezoidal side weir</a> </p> <a href="https://publications.waset.org/abstracts/47362/investigation-of-flow-characteristics-of-trapezoidal-side-weir-in-rectangular-channel-for-subcritical-flow" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/47362.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">87</span> Seismic Fragility of Weir Structure Considering Aging Degradation of Concrete Material </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=HoYoung%20Son">HoYoung Son</a>, <a href="https://publications.waset.org/abstracts/search?q=DongHoon%20Shin"> DongHoon Shin</a>, <a href="https://publications.waset.org/abstracts/search?q=WooYoung%20Jung"> WooYoung Jung</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This study presented the seismic fragility framework of concrete weir structure subjected to strong seismic ground motions and in particular, concrete aging condition of the weir structure was taken into account in this study. In order to understand the influence of concrete aging on the weir structure, by using probabilistic risk assessment, the analytical seismic fragility of the weir structure was derived for pre- and post-deterioration of concrete. The performance of concrete weir structure after five years was assumed for the concrete aging or deterioration, and according to after five years’ condition, the elastic modulus was simply reduced about one–tenth compared with initial condition of weir structures. A 2D nonlinear finite element analysis was performed considering the deterioration of concrete in weir structures using ABAQUS platform, a commercial structural analysis program. Simplified concrete degradation was resulted in the increase of almost 45% of the probability of failure at Limit State 3, in comparison to initial construction stage, by analyzing the seismic fragility. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=weir" title="weir">weir</a>, <a href="https://publications.waset.org/abstracts/search?q=FEM" title=" FEM"> FEM</a>, <a href="https://publications.waset.org/abstracts/search?q=concrete" title=" concrete"> concrete</a>, <a href="https://publications.waset.org/abstracts/search?q=fragility" title=" fragility"> fragility</a>, <a href="https://publications.waset.org/abstracts/search?q=aging" title=" aging"> aging</a> </p> <a href="https://publications.waset.org/abstracts/72469/seismic-fragility-of-weir-structure-considering-aging-degradation-of-concrete-material" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/72469.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">483</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">86</span> Seismic Safety Evaluation of Weir Structures Using the Finite and Infinite Element Method</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ho%20Young%20Son">Ho Young Son</a>, <a href="https://publications.waset.org/abstracts/search?q=Bu%20Seog%20Ju"> Bu Seog Ju</a>, <a href="https://publications.waset.org/abstracts/search?q=Woo%20Young%20Jung"> Woo Young Jung</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This study presents the seismic safety evaluation of weir structure subjected to strong earthquake ground motions, as a flood defense structure in civil engineering structures. The seismic safety analysis procedure was illustrated through development of Finite Element (FE) and InFinite Element (IFE) method in ABAQUS platform. The IFE model was generated by CINPS4, 4-node linear one-way infinite model as a sold continuum infinite element in foundation areas of the weir structure and then nonlinear FE model using friction model for soil-structure interactions was applied in this study. In order to understand the complex behavior of weir structures, nonlinear time history analysis was carried out. Consequently, it was interesting to note that the compressive stress gave more vulnerability to the weir structure, in comparison to the tensile stress, during an earthquake. The stress concentration of the weir structure was shown at the connection area between the weir body and stilling basin area. The stress both tension and compression was reduced in IFE model rather than FE model of weir structures. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=seismic" title="seismic">seismic</a>, <a href="https://publications.waset.org/abstracts/search?q=numerical%20analysis" title=" numerical analysis"> numerical analysis</a>, <a href="https://publications.waset.org/abstracts/search?q=FEM" title=" FEM"> FEM</a>, <a href="https://publications.waset.org/abstracts/search?q=weir" title=" weir"> weir</a>, <a href="https://publications.waset.org/abstracts/search?q=boundary%20condition" title=" boundary condition"> boundary condition</a> </p> <a href="https://publications.waset.org/abstracts/47886/seismic-safety-evaluation-of-weir-structures-using-the-finite-and-infinite-element-method" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/47886.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">452</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">85</span> Fragility Analysis of Weir Structure Subjected to Flooding Water Damage</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Oh%20Hyeon%20Jeon">Oh Hyeon Jeon</a>, <a href="https://publications.waset.org/abstracts/search?q=WooYoung%20Jung"> WooYoung Jung</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this study, seepage analysis was performed by the level difference between upstream and downstream of weir structure for safety evaluation of weir structure against flooding. Monte Carlo Simulation method was employed by considering the probability distribution of the adjacent ground parameter, i.e., permeability coefficient of weir structure. Moreover, by using a commercially available finite element program (ABAQUS), modeling of the weir structure is carried out. Based on this model, the characteristic of water seepage during flooding was determined at each water level with consideration of the uncertainty of their corresponding permeability coefficient. Subsequently, fragility function could be constructed based on this response from numerical analysis; this fragility function results could be used to determine the weakness of weir structure subjected to flooding disaster. They can also be used as a reference data that can comprehensively predict the probability of failur,e and the degree of damage of a weir structure. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=weir%20structure" title="weir structure">weir structure</a>, <a href="https://publications.waset.org/abstracts/search?q=seepage" title=" seepage"> seepage</a>, <a href="https://publications.waset.org/abstracts/search?q=flood%20disaster%20fragility" title=" flood disaster fragility"> flood disaster fragility</a>, <a href="https://publications.waset.org/abstracts/search?q=probabilistic%20risk%20assessment" title=" probabilistic risk assessment"> probabilistic risk assessment</a>, <a href="https://publications.waset.org/abstracts/search?q=Monte-Carlo%20simulation" title=" Monte-Carlo simulation"> Monte-Carlo simulation</a>, <a href="https://publications.waset.org/abstracts/search?q=permeability%20coefficient" title=" permeability coefficient"> permeability coefficient</a> </p> <a href="https://publications.waset.org/abstracts/88549/fragility-analysis-of-weir-structure-subjected-to-flooding-water-damage" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/88549.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">352</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">84</span> Experimental Study of Discharge with Sharp-Crested Weirs</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=E.%20Keramaris">E. Keramaris</a>, <a href="https://publications.waset.org/abstracts/search?q=V.%20Kanakoudis"> V. Kanakoudis</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this study the water flow in an open channel over a sharp-crested weir is investigated experimentally. For this reason a series of laboratory experiments were performed in an open channel with a sharp-crested weir. The maximum head expected over the weir, the total upstream water height and the downstream water height of the impact in the constant bed of the open channel were measured. The discharge was measured using a tank put right after the open channel. In addition, the discharge and the upstream velocity were also calculated using already known equations. The main finding is that the relative error percentage for the majority of the experimental measurements is ± 4%, meaning that the calculation of the discharge with a sharp-crested weir gives very good results compared to the numerical results from known equations. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=sharp-crested%20weir" title="sharp-crested weir">sharp-crested weir</a>, <a href="https://publications.waset.org/abstracts/search?q=weir%20height" title=" weir height"> weir height</a>, <a href="https://publications.waset.org/abstracts/search?q=flow%20measurement" title=" flow measurement"> flow measurement</a>, <a href="https://publications.waset.org/abstracts/search?q=open%20channel%20flow" title=" open channel flow"> open channel flow</a> </p> <a href="https://publications.waset.org/abstracts/117918/experimental-study-of-discharge-with-sharp-crested-weirs" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/117918.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">139</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">83</span> Seismic Fragility for Sliding Failure of Weir Structure Considering the Process of Concrete Aging</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=HoYoung%20Son">HoYoung Son</a>, <a href="https://publications.waset.org/abstracts/search?q=Ki%20Young%20Kim"> Ki Young Kim</a>, <a href="https://publications.waset.org/abstracts/search?q=Woo%20Young%20Jung"> Woo Young Jung</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This study investigated the change of weir structure performances when durability of concrete, which is the main material of weir structure, decreased due to their aging by mean of seismic fragility analysis. In the analysis, it was assumed that the elastic modulus of concrete was reduced by 10% in order to account for their aged deterioration. Additionally, the analysis of seismic fragility was based on Monte Carlo Simulation method combined with a 2D nonlinear finite element in ABAQUS platform with the consideration of deterioration of concrete. Finally, the comparison of seismic fragility of model pre- and post-deterioration was made to study the performance of weir. Results show that the probability of failure in moderate damage for deteriorated model was found to be larger than pre-deterioration model when peak ground acceleration (PGA) passed 0.4 g. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=weir" title="weir">weir</a>, <a href="https://publications.waset.org/abstracts/search?q=FEM" title=" FEM"> FEM</a>, <a href="https://publications.waset.org/abstracts/search?q=concrete" title=" concrete"> concrete</a>, <a href="https://publications.waset.org/abstracts/search?q=fragility" title=" fragility"> fragility</a>, <a href="https://publications.waset.org/abstracts/search?q=aging" title=" aging"> aging</a> </p> <a href="https://publications.waset.org/abstracts/68378/seismic-fragility-for-sliding-failure-of-weir-structure-considering-the-process-of-concrete-aging" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/68378.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">424</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">82</span> The Effect of the Side-Weir Crest Height to Scour in Clay-Sand Mixed Sediments </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=F.%20A.%20Saracoglu%20Varol">F. A. Saracoglu Varol</a>, <a href="https://publications.waset.org/abstracts/search?q=H.%20Agacc%C4%B1oglu"> H. Agaccıoglu </a> </p> <p class="card-text"><strong>Abstract:</strong></p> Experimental studies to investigate the depth of the scour conducted at a side-weir intersection located at the 1800 curved flume which located Hydraulic Laboratory of Yıldız Technical University, Istanbul, Turkey. Side weirs were located at the middle of the straight part of the main channel. Three different lengths (25, 40 and 50 cm) and three different weir crest height (7, 10 and 12 cm) of the side weir placed on the side weir station. There is no scour when the material is only kaolin. Therefore, the cohesive bed was prepared by properly mixing clay material (kaolin) with 31% sand in all experiments. Following 24h consolidation time, in order to observe the effect of flow intensity on the scour depth, experiments were carried out for five different upstream Froude numbers in the range of 0.33-0.81. As a result of this study the relation between scour depth and upstream flow intensity as a function of time have been established. The longitudinal velocities decreased along the side weir; towards the downstream due to overflow over the side-weirs. At the beginning, the scour depth increases rapidly with time and then asymptotically approached constant values in all experiments for all side weir dimensions as in non-cohesive sediment. Thus, the scour depth reached equilibrium conditions. Time to equilibrium depends on the approach flow intensity and the dimensions of side weirs. For different heights of the weir crest, dimensionless scour depths increased with increasing upstream Froude number. Equilibrium scour depths which formed 7 cm side-weir crest height were obtained higher than that of the 12 cm side-weir crest height. This means when side-weir crest height increased equilibrium scour depths decreased. Although the upstream side of the scour hole is almost vertical, the downstream side of the hole is inclined. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=clay-sand%20mixed%20sediments" title="clay-sand mixed sediments">clay-sand mixed sediments</a>, <a href="https://publications.waset.org/abstracts/search?q=scour" title=" scour"> scour</a>, <a href="https://publications.waset.org/abstracts/search?q=side%20weir" title=" side weir"> side weir</a>, <a href="https://publications.waset.org/abstracts/search?q=hydraulic%20structures" title=" hydraulic structures"> hydraulic structures</a> </p> <a href="https://publications.waset.org/abstracts/27481/the-effect-of-the-side-weir-crest-height-to-scour-in-clay-sand-mixed-sediments" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/27481.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">308</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">81</span> Bearing Capacity of Sheet Hanger Connection to the Trapezoidal Metal Sheet</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Kate%C5%99ina%20Jurdov%C3%A1">Kateřina Jurdová</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Hanging to the trapezoidal sheet by decking hanger is a very widespread solution used in civil engineering to lead the distribution of energy, sanitary, air distribution system etc. under the roof or floor structure. The trapezoidal decking hanger is usually a part of the whole installation system for specific distribution medium. The leading companies offer installation systems for each specific distribution e.g. pipe rings, sprinkler systems, installation channels etc. Every specific part is connected to the base connector which is decking hanger. The own connection has three main components: decking hanger, threaded bar with nuts and web of trapezoidal sheet. The aim of this contribution is determinate the failure mechanism of each component in connection. Load bearing capacity of most components in connection could be calculated by formulas in European codes. This contribution is focused on problematic of bearing resistance of threaded bar in web of trapezoidal sheet. This issue is studied by experimental research and numerical modelling. This contribution presented the initial results of experiment which is compared with numerical model of specimen. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=decking%20hanger" title="decking hanger">decking hanger</a>, <a href="https://publications.waset.org/abstracts/search?q=concentrated%20load" title=" concentrated load"> concentrated load</a>, <a href="https://publications.waset.org/abstracts/search?q=connection" title=" connection"> connection</a>, <a href="https://publications.waset.org/abstracts/search?q=load%20bearing%20capacity" title=" load bearing capacity"> load bearing capacity</a>, <a href="https://publications.waset.org/abstracts/search?q=trapezoidal%20metal%20sheet" title=" trapezoidal metal sheet"> trapezoidal metal sheet</a> </p> <a href="https://publications.waset.org/abstracts/11314/bearing-capacity-of-sheet-hanger-connection-to-the-trapezoidal-metal-sheet" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/11314.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">392</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">80</span> The Pressure Distribution on the Rectangular and Trapezoidal Storage Tanks' Perimeters Due to Liquid Sloshing Impact</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Hassan%20Saghi">Hassan Saghi</a>, <a href="https://publications.waset.org/abstracts/search?q=Gholam%20Reza%20Askarzadeh%20Garmroud"> Gholam Reza Askarzadeh Garmroud</a>, <a href="https://publications.waset.org/abstracts/search?q=Seyyed%20Ali%20Reza%20Emamian"> Seyyed Ali Reza Emamian</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Sloshing phenomenon is a complicated free surface flow problem that increases the dynamic pressure on the sidewalls and the bottom of the storage tanks. When the storage tanks are partially filled, it is essential to be able to evaluate the fluid dynamic loads on the tank’s perimeter. In this paper, a numerical code was developed to determine the pressure distribution on the rectangular and trapezoidal storage tanks’ perimeters due to liquid sloshing impact. Assuming the fluid to be inviscid, the Laplace equation and the nonlinear free surface boundary conditions are solved using coupled BEM-FEM. The code performance for sloshing modeling is validated against available data. Finally, this code is used for partially filled rectangular and trapezoidal storage tanks and the pressure distribution on the tanks’ perimeters due to liquid sloshing impact is estimated. The results show that the maximum pressure on the perimeter of the rectangular and trapezoidal storage tanks was decreased along the sidewalls from the top to the bottom. Furthermore, the period of the pressure distribution is different for different points on the tank’s perimeter and it is bigger in the trapezoidal tanks compared to the rectangular ones. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=pressure%20distribution" title="pressure distribution">pressure distribution</a>, <a href="https://publications.waset.org/abstracts/search?q=liquid%20sloshing%20impact" title=" liquid sloshing impact"> liquid sloshing impact</a>, <a href="https://publications.waset.org/abstracts/search?q=sway%20motion" title=" sway motion"> sway motion</a>, <a href="https://publications.waset.org/abstracts/search?q=trapezoidal%20storage%20tank" title=" trapezoidal storage tank"> trapezoidal storage tank</a>, <a href="https://publications.waset.org/abstracts/search?q=coupled%20BEM-FEM" title=" coupled BEM-FEM"> coupled BEM-FEM</a> </p> <a href="https://publications.waset.org/abstracts/20717/the-pressure-distribution-on-the-rectangular-and-trapezoidal-storage-tanks-perimeters-due-to-liquid-sloshing-impact" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/20717.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">551</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">79</span> A Trapezoidal-Like Integrator for the Numerical Solution of One-Dimensional Time Dependent Schrödinger Equation</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Johnson%20Oladele%20Fatokun">Johnson Oladele Fatokun</a>, <a href="https://publications.waset.org/abstracts/search?q=I.%20P.%20Akpan"> I. P. Akpan</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In this paper, the one-dimensional time dependent Schrödinger equation is discretized by the method of lines using a second order finite difference approximation to replace the second order spatial derivative. The evolving system of stiff ordinary differential equation (ODE) in time is solved numerically by an L-stable trapezoidal-like integrator. Results show accuracy of relative maximum error of order 10-4 in the interval of consideration. The performance of the method as compared to an existing scheme is considered favorable. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Schrodinger%E2%80%99s%20equation" title="Schrodinger’s equation">Schrodinger’s equation</a>, <a href="https://publications.waset.org/abstracts/search?q=partial%20differential%20equations" title=" partial differential equations"> partial differential equations</a>, <a href="https://publications.waset.org/abstracts/search?q=method%20of%20lines%20%28MOL%29" title=" method of lines (MOL)"> method of lines (MOL)</a>, <a href="https://publications.waset.org/abstracts/search?q=stiff%20ODE" title=" stiff ODE"> stiff ODE</a>, <a href="https://publications.waset.org/abstracts/search?q=trapezoidal-like%20integrator" title=" trapezoidal-like integrator "> trapezoidal-like integrator </a> </p> <a href="https://publications.waset.org/abstracts/11665/a-trapezoidal-like-integrator-for-the-numerical-solution-of-one-dimensional-time-dependent-schrodinger-equation" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/11665.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">417</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">78</span> A New Aggregation Operator for Trapezoidal Fuzzy Numbers Based On the Geometric Means of the Left and Right Line Slopes </h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Manju%20Pandey">Manju Pandey</a>, <a href="https://publications.waset.org/abstracts/search?q=Nilay%20Khare"> Nilay Khare</a>, <a href="https://publications.waset.org/abstracts/search?q=S.%20C.%20Shrivastava"> S. C. Shrivastava</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper is the final in a series, which has defined two new classes of aggregation operators for triangular and trapezoidal fuzzy numbers based on the geometrical characteristics of their fuzzy membership functions. In the present paper, a new aggregation operator for trapezoidal fuzzy numbers has been defined. The new operator is based on the geometric mean of the membership lines to the left and right of the maximum possibility interval. The operator is defined and the analytical relationships have been derived. Computation of the aggregate is demonstrated with a numerical example. Corresponding arithmetic and geometric aggregates as well as results from the recent work of the authors on TrFN aggregates have also been computed. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=LR%20fuzzy%20number" title="LR fuzzy number">LR fuzzy number</a>, <a href="https://publications.waset.org/abstracts/search?q=interval%20fuzzy%20number" title=" interval fuzzy number"> interval fuzzy number</a>, <a href="https://publications.waset.org/abstracts/search?q=triangular%20fuzzy%20number" title=" triangular fuzzy number"> triangular fuzzy number</a>, <a href="https://publications.waset.org/abstracts/search?q=trapezoidal%20fuzzy%20number" title=" trapezoidal fuzzy number"> trapezoidal fuzzy number</a>, <a href="https://publications.waset.org/abstracts/search?q=apex%20angle" title=" apex angle"> apex angle</a>, <a href="https://publications.waset.org/abstracts/search?q=left%20apex%20angle" title=" left apex angle"> left apex angle</a>, <a href="https://publications.waset.org/abstracts/search?q=right%20apex%20angle" title=" right apex angle"> right apex angle</a>, <a href="https://publications.waset.org/abstracts/search?q=aggregation%20operator" title=" aggregation operator"> aggregation operator</a>, <a href="https://publications.waset.org/abstracts/search?q=arithmetic%20and%20geometric%20mean" title=" arithmetic and geometric mean"> arithmetic and geometric mean</a> </p> <a href="https://publications.waset.org/abstracts/18890/a-new-aggregation-operator-for-trapezoidal-fuzzy-numbers-based-on-the-geometric-means-of-the-left-and-right-line-slopes" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/18890.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">472</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">77</span> Numerical Optimization of Trapezoidal Microchannel Heat Sinks</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Yue-Tzu%20Yang">Yue-Tzu Yang</a>, <a href="https://publications.waset.org/abstracts/search?q=Shu-Ching%20Liao"> Shu-Ching Liao</a> </p> <p class="card-text"><strong>Abstract:</strong></p> This study presents the numerical simulation of three-dimensional incompressible steady and laminar fluid flow and conjugate heat transfer of a trapezoidal microchannel heat sink using water as a cooling fluid in a silicon substrate. Navier-Stokes equations with conjugate energy equation are discretized by finite-volume method. We perform numerical computations for a range of 50 ≦ Re ≦ 600, 0.05W ≦ P ≦ 0.8W, 20W/cm2 ≦ ≦ 40W/cm2. The present study demonstrates the numerical optimization of a trapezoidal microchannel heat sink design using the response surface methodology (RSM) and the genetic algorithm method (GA). The results show that the average Nusselt number increases with an increase in the Reynolds number or pumping power, and the thermal resistance decreases as the pumping power increases. The thermal resistance of a trapezoidal microchannel is minimized for a constant heat flux and constant pumping power. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=microchannel%20heat%20sinks" title="microchannel heat sinks">microchannel heat sinks</a>, <a href="https://publications.waset.org/abstracts/search?q=conjugate%20heat%20transfer" title=" conjugate heat transfer"> conjugate heat transfer</a>, <a href="https://publications.waset.org/abstracts/search?q=optimization" title=" optimization"> optimization</a>, <a href="https://publications.waset.org/abstracts/search?q=genetic%20algorithm%20method" title=" genetic algorithm method"> genetic algorithm method</a> </p> <a href="https://publications.waset.org/abstracts/7509/numerical-optimization-of-trapezoidal-microchannel-heat-sinks" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/7509.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">319</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">76</span> Impact of Fin Cross Section Shape on Potential Distribution of Nanoscale Trapezoidal FinFETs</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ahmed%20Nassim%20Moulai%20Khatir">Ahmed Nassim Moulai Khatir</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Fin field effect transistors (FinFETs) deliver superior levels of scalability than the classical structure of MOSFETs by offering the elimination of short channel effects. Modern FinFETs are 3D structures that rise above the planar substrate, but some of these structures have inclined surfaces, which results in trapezoidal cross sections instead of rectangular sections usually used. Fin cross section shape of FinFETs results in some device issues, like potential distribution performance. This work analyzes that impact with three-dimensional numeric simulation of several triple-gate FinFETs with various top and bottom widths of fin. Results of the simulation show that the potential distribution and the electrical field in the fin depend on the sidewall inclination angle. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=FinFET" title="FinFET">FinFET</a>, <a href="https://publications.waset.org/abstracts/search?q=cross%20section%20shape" title=" cross section shape"> cross section shape</a>, <a href="https://publications.waset.org/abstracts/search?q=SILVACO" title=" SILVACO"> SILVACO</a>, <a href="https://publications.waset.org/abstracts/search?q=trapezoidal%20FinFETs" title=" trapezoidal FinFETs"> trapezoidal FinFETs</a> </p> <a href="https://publications.waset.org/abstracts/186029/impact-of-fin-cross-section-shape-on-potential-distribution-of-nanoscale-trapezoidal-finfets" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/186029.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">47</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">75</span> Development of Extended Trapezoidal Method for Numerical Solution of Volterra Integro-Differential Equations</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Fuziyah%20Ishak">Fuziyah Ishak</a>, <a href="https://publications.waset.org/abstracts/search?q=Siti%20Norazura%20Ahmad"> Siti Norazura Ahmad</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Volterra integro-differential equations appear in many models for real life phenomena. Since analytical solutions for this type of differential equations are hard and at times impossible to attain, engineers and scientists resort to numerical solutions that can be made as accurately as possible. Conventionally, numerical methods for ordinary differential equations are adapted to solve Volterra integro-differential equations. In this paper, numerical solution for solving Volterra integro-differential equation using extended trapezoidal method is described. Formulae for the integral and differential parts of the equation are presented. Numerical results show that the extended method is suitable for solving first order Volterra integro-differential equations. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=accuracy" title="accuracy">accuracy</a>, <a href="https://publications.waset.org/abstracts/search?q=extended%20trapezoidal%20method" title=" extended trapezoidal method"> extended trapezoidal method</a>, <a href="https://publications.waset.org/abstracts/search?q=numerical%20solution" title=" numerical solution"> numerical solution</a>, <a href="https://publications.waset.org/abstracts/search?q=Volterra%20integro-differential%20equations" title=" Volterra integro-differential equations"> Volterra integro-differential equations</a> </p> <a href="https://publications.waset.org/abstracts/52856/development-of-extended-trapezoidal-method-for-numerical-solution-of-volterra-integro-differential-equations" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/52856.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">424</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">74</span> Reduction of Toxic Matter from Marginal Water Using Sludge Recycling from Combination of Stepped Cascade Weir with Limestone Trickling Filter</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Dheyaa%20Wajid%20Abbood">Dheyaa Wajid Abbood</a>, <a href="https://publications.waset.org/abstracts/search?q=Eitizaz%20Awad%20Jasim"> Eitizaz Awad Jasim</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The aim of this investigation is to confirm the activity of a sludge recycling process in trickling filter filled with limestone as an alternative biological process over conventional high-cost treatment process with regard to toxic matter reduction from marginal water. The combination system of stepped cascade weir with limestone trickling filter has been designed and constructed in the environmental hydraulic laboratory, Al-Mustansiriya University, College of Engineering. A set of experiments has been conducted during the period from August 2013 to July 2014. Seven days of continuous operation with different continuous flow rates (0.4m3/hr, 0.5 m3/hr, 0.6 m3/hr, 0.7m3/hr,0.8 m3/hr, 0.9 m3/hr, and 1m3/hr) after ten days of acclimatization experiments were carried out. Results indicate that the concentrations of toxic matter were decreasing with increasing of operation time, sludge recirculation ratio, and flow rate. The toxic matter measured includes (Mineral oils, Petroleum products, Phenols, Biocides, Polychlorinated biphenyls (PCBs), and Surfactants) which are used in these experiments were ranged between (0.074 nm-0.156 nm). Results indicated that the overall reduction efficiency after 4, 28, 52, 76, 100, 124, and 148 hours of operation were (55%, 48%, 42%, 50%, 59%, 61%, and 64%) when the combination of stepped cascade weir with limestone trickling filter is used. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=toxic%20matter" title="toxic matter">toxic matter</a>, <a href="https://publications.waset.org/abstracts/search?q=marginal%20water" title=" marginal water"> marginal water</a>, <a href="https://publications.waset.org/abstracts/search?q=trickling%20filter" title=" trickling filter"> trickling filter</a>, <a href="https://publications.waset.org/abstracts/search?q=stepped%20cascade%20weir" title=" stepped cascade weir"> stepped cascade weir</a>, <a href="https://publications.waset.org/abstracts/search?q=removal%20efficiency" title=" removal efficiency"> removal efficiency</a> </p> <a href="https://publications.waset.org/abstracts/32593/reduction-of-toxic-matter-from-marginal-water-using-sludge-recycling-from-combination-of-stepped-cascade-weir-with-limestone-trickling-filter" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/32593.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">297</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">73</span> Reduction of Toxic Matter from Marginal Water Treatment Using Sludge Recycling from Combination of Stepped Cascade Weir with Limestone Trickling Filter</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Dheyaa%20Wajid%20Abbood">Dheyaa Wajid Abbood</a>, <a href="https://publications.waset.org/abstracts/search?q=Ali%20Mohammed%20Tawfeeq%20Baqer"> Ali Mohammed Tawfeeq Baqer</a>, <a href="https://publications.waset.org/abstracts/search?q=Eitizaz%20Awad%20Jasim"> Eitizaz Awad Jasim</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The aim of this investigation is to confirm the activity of a sludge recycling process in trickling filter filled with limestone as an alternative biological process over conventional high-cost treatment process with regard to toxic matter reduction from marginal water. The combination system of stepped cascade weir with limestone trickling filter has been designed and constructed in the Environmental Hydraulic Laboratory, Al-Mustansiriya University, College of Engineering. A set of experiments has been conducted during the period from August 2013 to July 2014. Seven days of continuous operation with different continuous flow rates (0.4m3/hr, 0.5 m3/hr, 0.6 m3/hr, 0.7m3/hr,0.8 m3/hr, 0.9 m3/hr, and 1m3/hr) after ten days of acclimatization experiments were carried out. Results indicate that the concentrations of toxic matter were decreasing with increasing of operation time, sludge recirculation ratio, and flow rate. The toxic matter measured includes (Mineral oils, Petroleum products, Phenols, Biocides, Polychlorinated biphenyls (PCBs), and Surfactants) which are used in these experiments were ranged between (0.074 nm-0.156 nm). Results indicated that the overall reduction efficiency after 4, 28, 52, 76, 100, 124, and 148 hours of operation were (55%, 48%, 42%, 50%, 59%, 61%, and 64%) when the combination of stepped cascade weir with limestone trickling filter is used. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=Marginal%20water" title="Marginal water ">Marginal water </a>, <a href="https://publications.waset.org/abstracts/search?q=Toxic%20matter" title="Toxic matter">Toxic matter</a>, <a href="https://publications.waset.org/abstracts/search?q=Stepped%20Cascade%20weir" title=" Stepped Cascade weir"> Stepped Cascade weir</a>, <a href="https://publications.waset.org/abstracts/search?q=limestone%20trickling%20filter" title=" limestone trickling filter"> limestone trickling filter</a> </p> <a href="https://publications.waset.org/abstracts/33447/reduction-of-toxic-matter-from-marginal-water-treatment-using-sludge-recycling-from-combination-of-stepped-cascade-weir-with-limestone-trickling-filter" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/33447.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">396</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">72</span> Numerical Investigation of Flow Behaviour Across a Trapezoidal Bluff Body at Low Reynolds Number</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Zaaraoui%20Abdelkader">Zaaraoui Abdelkader</a>, <a href="https://publications.waset.org/abstracts/search?q=Kerfah%20Rabeh"> Kerfah Rabeh</a>, <a href="https://publications.waset.org/abstracts/search?q=Noura%20Belkheir"> Noura Belkheir</a>, <a href="https://publications.waset.org/abstracts/search?q=Matene%20Elhacene"> Matene Elhacene</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The trapezoidal bluff body is a typical configuration of vortex shedding bodies. The aim of this work is to study flow behaviour over a trapezoidal cylinder at low Reynolds number. The geometry was constructed from a prototype device for measuring the volumetric flow-rate by counting vortices. Simulations were run for this geometry under steady and unsteady flow conditions using finite volume discretization. Laminar flow was investigated in this model with rigid walls and homogeneous incompressible Newtonian fluid. Calculations were performed for Reynolds number range 5 ≤ Re ≤ 180 and several flow parameters were documented. The present computations are in good agreement with the experimental observations and the numerical calculations by several investigators. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=bluff%20body" title="bluff body">bluff body</a>, <a href="https://publications.waset.org/abstracts/search?q=confined%20flow" title=" confined flow"> confined flow</a>, <a href="https://publications.waset.org/abstracts/search?q=numerical%20calculations" title=" numerical calculations"> numerical calculations</a>, <a href="https://publications.waset.org/abstracts/search?q=steady%20and%20unsteady%20flow" title=" steady and unsteady flow"> steady and unsteady flow</a>, <a href="https://publications.waset.org/abstracts/search?q=vortex%20shedding%20flow%20meter" title=" vortex shedding flow meter"> vortex shedding flow meter</a> </p> <a href="https://publications.waset.org/abstracts/54144/numerical-investigation-of-flow-behaviour-across-a-trapezoidal-bluff-body-at-low-reynolds-number" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/54144.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">287</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">71</span> Non-Differentiable Mond-Weir Type Symmetric Duality under Generalized Invexity</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Jai%20Prakash%20Verma">Jai Prakash Verma</a>, <a href="https://publications.waset.org/abstracts/search?q=Khushboo%20Verma"> Khushboo Verma</a> </p> <p class="card-text"><strong>Abstract:</strong></p> In the present paper, a pair of Mond-Weir type non-differentiable multiobjective second-order programming problems, involving two kernel functions, where each of the objective functions contains support function, is formulated. We prove weak, strong and converse duality theorem for the second-order symmetric dual programs under η-pseudoinvexity conditions. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=non-differentiable%20multiobjective%20programming" title="non-differentiable multiobjective programming">non-differentiable multiobjective programming</a>, <a href="https://publications.waset.org/abstracts/search?q=second-order%20symmetric%20duality" title=" second-order symmetric duality"> second-order symmetric duality</a>, <a href="https://publications.waset.org/abstracts/search?q=efficiency" title=" efficiency"> efficiency</a>, <a href="https://publications.waset.org/abstracts/search?q=support%20function" title=" support function"> support function</a>, <a href="https://publications.waset.org/abstracts/search?q=eta-pseudoinvexity" title=" eta-pseudoinvexity"> eta-pseudoinvexity</a> </p> <a href="https://publications.waset.org/abstracts/57852/non-differentiable-mond-weir-type-symmetric-duality-under-generalized-invexity" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/57852.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">249</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">70</span> Analysis of Brushless DC Motor with Trapezoidal Back EMF Using Matlab</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Taha%20Ahmed%20Husain">Taha Ahmed Husain</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The dynamic characteristics such as speed and torque as well as voltages and currents of pwm brushless DC motor inverter are analyzed with a MATLAB model. The contribution of external load torque and friction torque is monitored. The switching function technique is adopted for the current control of the embedded three phase inverter that drives the brushless DC motor.In switching functions the power conversions circuits can be modeled according to their functions rather than circuit topologies. Therefore, it can achieve simplification of the overall power conversion functions. The trapezoidal type (back emf) is used in the model as ithas lower switching loss compared with sinusoidal type (back emf). Results show reliable time analysis for speed, torque, phase and line voltages and currents and the effect of current commutation is clearly observed. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=BLDC%20motor" title="BLDC motor">BLDC motor</a>, <a href="https://publications.waset.org/abstracts/search?q=brushless%20dc%20motors" title=" brushless dc motors"> brushless dc motors</a>, <a href="https://publications.waset.org/abstracts/search?q=pwm%20inverter" title=" pwm inverter"> pwm inverter</a>, <a href="https://publications.waset.org/abstracts/search?q=DC%20motor%20control" title=" DC motor control"> DC motor control</a>, <a href="https://publications.waset.org/abstracts/search?q=trapezoidal%20back%20emf" title=" trapezoidal back emf"> trapezoidal back emf</a>, <a href="https://publications.waset.org/abstracts/search?q=ripple%20torque%20in%20brushless%20DC%20motor" title=" ripple torque in brushless DC motor"> ripple torque in brushless DC motor</a> </p> <a href="https://publications.waset.org/abstracts/22803/analysis-of-brushless-dc-motor-with-trapezoidal-back-emf-using-matlab" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/22803.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">598</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">69</span> Three-Dimensional Unsteady Natural Convection and Entropy Generation in an Inclined Cubical Trapezoidal Cavity Subjected to Uniformly Heated Bottom Wall</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Farshid%20Fathinia">Farshid Fathinia</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Numerical computation of unsteady laminar three-dimensional natural convection and entropy generation in an inclined cubical trapezoidal air-filled cavity is performed for the first time in this work. The vertical right and left sidewalls of the cavity are maintained at constant cold temperatures. The lower wall is subjected to a constant hot temperature, while the upper one is considered insulated. Computations are performed for Rayleigh numbers varied as 103 ≤ Ra ≤ 105, while the trapezoidal cavity inclination angle is varied as 0° ≤ ϕ ≤ 180°. Prandtl number is considered constant at Pr = 0.71. The second law of thermodynamics is applied to obtain thermodynamic losses inside the cavity due to both heat transfer and fluid friction irreversibilities. The variation of local and average Nusselt numbers are presented and discussed.While, streamlines, isotherms and entropy contours are presented in both two and three-dimensional pattern. The results show that when the Rayleigh number increases, the flow patterns are changed especially in three-dimensional results and the flow circulation increases. Also, the inclination angle effect on the total entropy generation becomes insignificant when the Rayleigh number is low.Moreover, when the Rayleigh number increases the average Nusselt number increases. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=transient%20natural%20convection" title="transient natural convection">transient natural convection</a>, <a href="https://publications.waset.org/abstracts/search?q=trapezoidal%20cavity" title=" trapezoidal cavity"> trapezoidal cavity</a>, <a href="https://publications.waset.org/abstracts/search?q=three-dimensional%20flow" title=" three-dimensional flow"> three-dimensional flow</a>, <a href="https://publications.waset.org/abstracts/search?q=entropy%20generation" title=" entropy generation"> entropy generation</a>, <a href="https://publications.waset.org/abstracts/search?q=second%20law" title=" second law "> second law </a> </p> <a href="https://publications.waset.org/abstracts/24831/three-dimensional-unsteady-natural-convection-and-entropy-generation-in-an-inclined-cubical-trapezoidal-cavity-subjected-to-uniformly-heated-bottom-wall" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/24831.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">349</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">68</span> Numerical Simulation of Unsteady Natural Convective Nanofluid Flow within a Trapezoidal Enclosure Using Meshfree Method</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=S.%20Nandal">S. Nandal</a>, <a href="https://publications.waset.org/abstracts/search?q=R.%20Bhargava"> R. Bhargava</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The paper contains a numerical study of the unsteady magneto-hydrodynamic natural convection flow of nanofluids within a symmetrical wavy walled trapezoidal enclosure. The length and height of enclosure are both considered equal to L. Two-phase nanofluid model is employed. The governing equations of nanofluid flow along with boundary conditions are non-dimensionalized and are solved using one of Meshfree technique (EFGM method). Meshfree numerical technique does not require a predefined mesh for discretization purpose. The bottom wavy wall of the enclosure is defined using a cosine function. Element free Galerkin method (EFGM) does not require the domain. The effects of various parameters namely time t, amplitude of bottom wavy wall a, Brownian motion parameter Nb and thermophoresis parameter Nt is examined on rate of heat and mass transfer to get a visualization of cooling and heating effects. Such problems have important applications in heat exchangers or solar collectors, as wavy walled enclosures enhance heat transfer in comparison to flat walled enclosures. <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=meshfree%20methods" title=" meshfree methods"> meshfree methods</a>, <a href="https://publications.waset.org/abstracts/search?q=nanofluid" title=" nanofluid"> nanofluid</a>, <a href="https://publications.waset.org/abstracts/search?q=trapezoidal%20enclosure" title=" trapezoidal enclosure"> trapezoidal enclosure</a> </p> <a href="https://publications.waset.org/abstracts/63284/numerical-simulation-of-unsteady-natural-convective-nanofluid-flow-within-a-trapezoidal-enclosure-using-meshfree-method" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/63284.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">157</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">67</span> Modeling Aeration of Sharp Crested Weirs by Using Support Vector Machines</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Arun%20Goel">Arun Goel </a> </p> <p class="card-text"><strong>Abstract:</strong></p> The present paper attempts to investigate the prediction of air entrainment rate and aeration efficiency of a free over-fall jets issuing from a triangular sharp crested weir by using regression based modelling. The empirical equations, support vector machine (polynomial and radial basis function) models and the linear regression techniques were applied on the triangular sharp crested weirs relating the air entrainment rate and the aeration efficiency to the input parameters namely drop height, discharge, and vertex angle. It was observed that there exists a good agreement between the measured values and the values obtained using empirical equations, support vector machine (Polynomial and rbf) models, and the linear regression techniques. The test results demonstrated that the SVM based (Poly & rbf) model also provided acceptable prediction of the measured values with reasonable accuracy along with empirical equations and linear regression techniques in modelling the air entrainment rate and the aeration efficiency of a free over-fall jets issuing from triangular sharp crested weir. Further sensitivity analysis has also been performed to study the impact of input parameter on the output in terms of air entrainment rate and aeration efficiency. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=air%20entrainment%20rate" title="air entrainment rate">air entrainment rate</a>, <a href="https://publications.waset.org/abstracts/search?q=dissolved%20oxygen" title=" dissolved oxygen"> dissolved oxygen</a>, <a href="https://publications.waset.org/abstracts/search?q=weir" title=" weir"> weir</a>, <a href="https://publications.waset.org/abstracts/search?q=SVM" title=" SVM"> SVM</a>, <a href="https://publications.waset.org/abstracts/search?q=regression" title=" regression"> regression</a> </p> <a href="https://publications.waset.org/abstracts/3752/modeling-aeration-of-sharp-crested-weirs-by-using-support-vector-machines" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/3752.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">436</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">66</span> Numerical Simulation of Sloshing Control Using Input Shaping</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Dongjoo%20Kim">Dongjoo Kim</a> </p> <p class="card-text"><strong>Abstract:</strong></p> Effective control of sloshing in a liquid container is an important issue to be resolved in many applications. In this study, numerical simulations are performed to design the velocity profile of rectangular container and investigate the effectiveness of input shaping for sloshing control. Trapezoidal profiles of container velocity are chosen to be reference commands and they are convolved with a series of impulses to generate shaped ones that induce minimal residual oscillations. The performances of several input shapers are compared from the viewpoint of transient peak and residual oscillations of sloshing. Results show that sloshing can be effectively controlled by input shaping (Supported by the NRF programs, NRF-2015R1D1A1A01059675, of Korean government). <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=input%20shaping" title="input shaping">input shaping</a>, <a href="https://publications.waset.org/abstracts/search?q=rectangular%20container" title=" rectangular container"> rectangular container</a>, <a href="https://publications.waset.org/abstracts/search?q=sloshing" title=" sloshing"> sloshing</a>, <a href="https://publications.waset.org/abstracts/search?q=trapezoidal%20profile" title=" trapezoidal profile"> trapezoidal profile</a> </p> <a href="https://publications.waset.org/abstracts/58020/numerical-simulation-of-sloshing-control-using-input-shaping" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/58020.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">260</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">65</span> An Approximation Algorithm for the Non Orthogonal Cutting Problem</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=R.%20Ouafi">R. Ouafi</a>, <a href="https://publications.waset.org/abstracts/search?q=F.%20Ouafi"> F. Ouafi </a> </p> <p class="card-text"><strong>Abstract:</strong></p> We study the problem of cutting a rectangular material entity into smaller sub-entities of trapezoidal forms with minimum waste of the material. This problem will be denoted TCP (Trapezoidal Cutting Problem). The TCP has many applications in manufacturing processes of various industries: pipe line design (petro chemistry), the design of airfoil (aeronautical) or cuts of the components of textile products. We introduce an orthogonal build to provide the optimal horizontal and vertical homogeneous strips. In this paper we develop a general heuristic search based upon orthogonal build. By solving two one-dimensional knapsack problems, we combine the horizontal and vertical homogeneous strips to give a non orthogonal cutting pattern. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=combinatorial%20optimization" title="combinatorial optimization">combinatorial optimization</a>, <a href="https://publications.waset.org/abstracts/search?q=cutting%20problem" title=" cutting problem"> cutting problem</a>, <a href="https://publications.waset.org/abstracts/search?q=heuristic" title=" heuristic"> heuristic</a> </p> <a href="https://publications.waset.org/abstracts/19497/an-approximation-algorithm-for-the-non-orthogonal-cutting-problem" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/19497.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">541</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">64</span> Thrust Enhancement on a Two Dimensional Elliptic Airfoil in a Forward Flight</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=S.%20M.%20Dash">S. M. Dash</a>, <a href="https://publications.waset.org/abstracts/search?q=K.%20B.%20Lua"> K. B. Lua</a>, <a href="https://publications.waset.org/abstracts/search?q=T.%20T.%20Lim"> T. T. Lim </a> </p> <p class="card-text"><strong>Abstract:</strong></p> This paper presents results of numerical and experimental studies on a two-dimensional (2D) flapping elliptic airfoil in a forward flight condition at Reynolds number of 5000. The study is motivated from an earlier investigation which shows that the deterioration in thrust performance of a sinusoidal heaving and pitching 2D (NACA0012) airfoil at high flapping frequency can be recovered by changing the effective angle of attack profile to square wave, sawtooth, or cosine wave shape. To better understand why such modifications lead to superior thrust performance, we take a closer look at the transient aerodynamic force behavior of an airfoil when the effective angle of attack profile changes gradually from a generic smooth trapezoidal profile to a sinusoid shape by modifying the base length of the trapezoid. The choice of using a smooth trapezoidal profile is to avoid the infinite acceleration condition encountered in the square wave profile. Our results show that the enhancement in the time-averaged thrust performance at high flapping frequency can be attributed to the delay and reduction in the drag producing valley region in the transient thrust force coefficient when the effective angle of attack profile changes from sinusoidal to trapezoidal. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=two-dimensional%20flapping%20airfoil" title="two-dimensional flapping airfoil">two-dimensional flapping airfoil</a>, <a href="https://publications.waset.org/abstracts/search?q=thrust%20performance" title=" thrust performance"> thrust performance</a>, <a href="https://publications.waset.org/abstracts/search?q=effective%20angle%20of%20attack" title=" effective angle of attack"> effective angle of attack</a>, <a href="https://publications.waset.org/abstracts/search?q=CFD" title=" CFD"> CFD</a>, <a href="https://publications.waset.org/abstracts/search?q=experiments" title=" experiments"> experiments</a> </p> <a href="https://publications.waset.org/abstracts/45043/thrust-enhancement-on-a-two-dimensional-elliptic-airfoil-in-a-forward-flight" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/45043.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">358</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">63</span> Mixing Enhancement with 3D Acoustic Streaming Flow Patterns Induced by Trapezoidal Triangular Structure Micromixer Using Different Mixing Fluids</h5> <div class="card-body"> <p class="card-text"><strong>Authors:</strong> <a href="https://publications.waset.org/abstracts/search?q=Ayalew%20Yimam%20%20Ali">Ayalew Yimam Ali</a> </p> <p class="card-text"><strong>Abstract:</strong></p> The T-shaped microchannel is used to mix both miscible or immiscible fluids with different viscosities. However, mixing at the entrance of the T-junction microchannel can be difficult mixing phenomena due to micro-scale laminar flow aspects with the two miscible high-viscosity water-glycerol fluids. One of the most promising methods to improve mixing performance and diffusion mass transfer in laminar flow phenomena is acoustic streaming (AS), which is a time-averaged, second-order steady streaming that can produce rolling motion in the microchannel by oscillating a low-frequency range acoustic transducer and inducing an acoustic wave in the flow field. The newly developed 3D trapezoidal, triangular structure spine used in this study was created using sophisticated CNC machine cutting tools used to create microchannel mold with a 3D trapezoidal triangular structure spine alone the T-junction longitudinal mixing region. In order to create the molds for the 3D trapezoidal structure with the 3D sharp edge tip angles of 30° and 0.3mm trapezoidal, triangular sharp edge tip depth from PMMA glass (Polymethylmethacrylate) with advanced CNC machine and the channel manufactured using PDMS (Polydimethylsiloxane) which is grown up longitudinally on the top surface of the Y-junction microchannel using soft lithography nanofabrication strategies. Flow visualization of 3D rolling steady acoustic streaming and mixing enhancement with high-viscosity miscible fluids with different trapezoidal, triangular structure longitudinal length, channel width, high volume flow rate, oscillation frequency, and amplitude using micro-particle image velocimetry (μPIV) techniques were used to study the 3D acoustic streaming flow patterns and mixing enhancement. The streaming velocity fields and vorticity flow fields show 16 times more high vorticity maps than in the absence of acoustic streaming, and mixing performance has been evaluated at various amplitudes, flow rates, and frequencies using the grayscale value of pixel intensity with MATLAB software. Mixing experiments were performed using fluorescent green dye solution with de-ionized water in one inlet side of the channel, and the de-ionized water-glycerol mixture on the other inlet side of the T-channel and degree of mixing was found to have greatly improved from 67.42% without acoustic streaming to 0.96.83% with acoustic streaming. The results show that the creation of a new 3D steady streaming rolling motion with a high volume flowrate around the entrance was enhanced by the formation of a new, three-dimensional, intense streaming rolling motion with a high-volume flowrate around the entrance junction mixing zone with the two miscible high-viscous fluids which are influenced by laminar flow fluid transport phenomena. <p class="card-text"><strong>Keywords:</strong> <a href="https://publications.waset.org/abstracts/search?q=micro%20fabrication" title="micro fabrication">micro fabrication</a>, <a href="https://publications.waset.org/abstracts/search?q=3d%20acoustic%20streaming%20flow%20visualization" title=" 3d acoustic streaming flow visualization"> 3d acoustic streaming flow visualization</a>, <a href="https://publications.waset.org/abstracts/search?q=micro-particle%20image%20velocimetry" title=" micro-particle image velocimetry"> micro-particle image velocimetry</a>, <a href="https://publications.waset.org/abstracts/search?q=mixing%20enhancement." title=" mixing enhancement."> mixing enhancement.</a> </p> <a href="https://publications.waset.org/abstracts/190156/mixing-enhancement-with-3d-acoustic-streaming-flow-patterns-induced-by-trapezoidal-triangular-structure-micromixer-using-different-mixing-fluids" class="btn btn-primary btn-sm">Procedia</a> <a href="https://publications.waset.org/abstracts/190156.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">20</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=trapezoidal%20weir&page=2">2</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=trapezoidal%20weir&page=3">3</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=trapezoidal%20weir&page=4">4</a></li> <li class="page-item"><a class="page-link" href="https://publications.waset.org/abstracts/search?q=trapezoidal%20weir&page=2" rel="next">&rsaquo;</a></li> </ul> </div> </main> <footer> <div id="infolinks" class="pt-3 pb-2"> <div class="container"> <div style="background-color:#f5f5f5;" class="p-3"> <div class="row"> <div class="col-md-2"> <ul class="list-unstyled"> About <li><a href="https://waset.org/page/support">About Us</a></li> <li><a href="https://waset.org/page/support#legal-information">Legal</a></li> <li><a target="_blank" rel="nofollow" href="https://publications.waset.org/static/files/WASET-16th-foundational-anniversary.pdf">WASET celebrates its 16th foundational anniversary</a></li> </ul> </div> <div class="col-md-2"> <ul class="list-unstyled"> 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