Hydraulic behaviour of flow over an oblique weir

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Hydraulic Design of Weir and Traffic Bridge Design1HYDRAULIC DESIGN OF WEIR AND TRAFFIC BRIDGE DESIGN FOR MONEY’SCREEKS LAGOONNameCourseProfessorUniversityCity/stateDate
Hydraulic Design of Weir and Traffic Bridge Design2Hydraulic Design of Weir and Traffic Bridge Design for Money’s Creeks LagoonLITERATURE REVIEWKeywords: hydraulic design, weir, discharge coefficient, flow characteristics, weir crest, weirlength, weir depth, bridgeDischarge characteristics of a modified oblique side weir in subcritical flowThis study evaluates the advantages of oblique weir over plain and labyrinth side weirs. One ofthe maina advantages of oblique side weirs is that they have a greater effective length foroverflowing, which diverts more discharge at the same opening of the channel. Their flowproperties and weir height is also more. The researchers carried out over 200 test measurementsand the results showed that the efficincy of oblque weirs is 2.33 times greater than that of othertypes of side weirs (plain and labyrnth)[ CITATION Bor111 \l 1033 ].They also presented flow andgeometrical variables as a function of discharge coefficient, which can be used by desgnengineers when designing weirs for different structures, such as traffic bridge.Flow characteristics of rectangular broad-crested weirs with sloped upstream faceIn this study, experimental studies were carried out to determine hydraulic flow characteristics ofrectangular-crested weirs with different upstream angles. The effect of changing upstream anglewas invested. The upstream slopes evaluated were 90, 75, 60, 45, 30, 22.5 and 10 degrees. Theparameters determined were flow separation zone, approach velocity profile, dischargecoefficient and flow surface pattern. The resarchers introduced a new corection factor forestimating discharge coefficient and a water surface mathematical relationhip. The resultsobtained from th study showed that an increase in upstream slope reduces discharge coefficient
Hydraulic Design of Weir and Traffic Bridge Design3value. The highest and minimum discharge coefficient values wwere recorded when upstreamslope was 10 and 90 degrees respectively[CITATION Flo12 \l 1033 ].Prediction of head loss on cascade weir using ANN and SVMIn this study, researchers appled support vector machine (SVM) method to predict flow head losson cascade weirs. The performance of this method was compared with other computingtechniques by developing a multilayer perception neural network. The resuts showed that SVMis a reliable technique of predicting head loss of weirs and it is more accurate than the othertechniques[ CITATION Hag17 \l 1033 ].Hydraulic design of side weirs by alternative methodsEven though side weirs are widely used to divert flows in channels, rivers, reservoirs and sewers,their hydraulic behavior is very dfficult and complex to predict using standard methods. Thisstudy presented a new design method of predicting side wers’ hydraulic behavior. The methodwas developed from vrious experimental studies carried out by the researchers. They came upwith a numerical model that can predict hydruic behavior of the side weir. The new procedurepresents results in form of simplified equations and graphs, making it easier for design engineersto establish hydraulic behaviors more easily and accurately[ CITATION Rah121 \l 1033 ].Predicting trapezoidal and rectangular side weirs discharge coefficient using machinelearning methodsSide weirs are very common and useful devices in measuring flow of water. To design a moreefficint weir, discharge coefficient has to be accuratey measured so as to create a precise flowmodel. In this study, researchers used two different machine learning techniques to predictdischarge coefficient of rectagular and trapezoidal side weirs. The methods used were SVM
Hydraulic Design of Weir and Traffic Bridge Design4(support vector machines) and GEP (gebe expression programming). The models’ perfoemancewas evaluated using correlation coefficient, Nash-Sutcliffe index (NS) and mean normalize erro(MNE). The results obtained showed that SVM is a more accurate method that GEP[ CITATIONRou161 \l 1033 ].Based on these results, designers and engineers should conider using moderntechnological tools such as artificial intelligence and machine learning to develop more accurateflow models of weirs.Discharge charcateristics of weirs of finite crest length with upstream and downstreamrampsThis study involved evaluation of open channel flow measurment of traverse weirs with finitecrest length, sloping crest and downstream or upstream ramps. Broad-crested weir equation wasused to develop correltions with discharge coefficient being used as the basis. Dowstream andupstream length scales were also introduced to investigate the effects of downstream andupstream ramps. The results obtained showed that an increase in downstream slope causes anincrease in discharge coefficient while an increase in upstream slope causes a decrease indischarge coefficient[ CITATION Azi131 \l 1033 ]. Design engineers can use this information toestablish the most appropriate downstream or upstream slope for the weir.Flow characteristics of rectangular sharp-crested side weirs in the presence of guide vanesIn this study, researchers evauated flow of water over rectangular sharp-crested side weirs withdifferent heights and widths. An acoustic Doppler velocity (ADV) meter was used to obtain 3Dvelocity of water flowing over the crest and within the side weir’s viscinity. The velocitydistribution results showed that longitudinal velocity was highest close to the beginning of theside weir while velocity in spill flow’s direction was maximum at the weir’s end. The results also
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