بررسي جريان همزمان از زير يك دريچه كشويي و روي يك سرريز ذوزنقه اي در يك كانال دايره اي

چكيده انگليسي :

Investigation of Simultaneose Flow under a Sluice Gate and Over a Trapezoidal Weir in a Circular Channel Maryam Pashazadeh Pashazade1387@Gmail com Department of Irrigation and Drainage Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiAbstract Sharp crested weirs and sluice gates because of their ease making water surface control potential and flow ratemeasuring have been broadly studied Since the nature of flow on the weirs is highly complicated mostly the drivenequations are taken in account a series of simplifier hypothesis that are on the base of empirical experiments On theother hand most of the weirs cause a relatively calm zone of water on their upstream which is a place of wastematerial and sediments to precipitate that is the disadvantage of the device With gradual storage of sediments thecondition of flow changed and driven equations will lose their precision In this case composition of weir and gatecan be a useful solution for passage of floating materials over the weir and transmission of sediment materials fromthe lower part of the gate In this study hydraulic characteristics of the 18 combined model of trapezoidal weir gatein the tree groups with three different opening gates at the end of an open channel with a circular cross section werestudied Also a series of complementary experiments in a circular channel without combined model included 18single trapezoidal sharp crested weirs model and a single sharp crested sluice gates model with three differentopening at the end of channel was performed in order to evaluating the properties of this type of model in circularchannel Using dimensional analysis analytical solutions and statistical analysis an equation for combineddischarge by combined model of weir gate was introduced The equation was evaluated by experimental data Finally Flow 3D software was used to evaluate the denotative flow from under and over of the combined models Passing flow from single weir model and single gate separately were simulated and analyzed Dimensional andstatistical analysis showed that discharge coefficient of the trapezoidal weir gate combined model depends on thefactors such as a opening angle of the weir in the combined model ratio of flow depth in the upstream todiameter of circular channel ratio of the distance of between the weir crest and floor to the depth of channelflow in the upstream ratio of head on the weir to gate opening ratio of the weir crest height to diameterof circular channel ratio of the weir crest length of the combined model to diameter of circular channel and ratio of gate opening to diameter of circular channel Numerical simulation results showed that the surfacetension of water does not affect the fluid flow and should not be involve in flow simulation by software in order tonumerical solution of the flow be conducted with greater accuracy With simulation of the passing flow from thecombined model and analysis of the local velocity values in the area of weir and gate the average horizontalvelocity value in the area of weir and gate was separately estimated Then considering the diverse surface area ofthe weir and gate in the combined model the passing segregated discharge from weir and gate during simultaneousperformance of two devices in the combined model of weir gate were obtained and from the sum of them thecombined total discharge with error of less than 0 9 percent compared to a laboratory discharge was calculated Insimulating of the passing segregated flow from the trapezoidal weir model at the end of circular channel resultsshowed that simulating program estimates the water surface profile value with a good accuracy slightly higher thanthe experimental values In simulating of the passing segregated flow from single gate model with 3cm opening atthe end of circular channel results showed simulating program in the state of completion time of 50 seconds due tothe relative stability of fluid flow in the channel estimate

پاشازاده، مريم

بررسي جريان همزمان از زير يك دريچه كشويي و روي يك سرريز ذوزنقه اي در يك كانال دايره اي

مدل تركيبي سرريز-دريچه ذوزنقه اي , ضريب ديي , آناليز ابعادي