Two Dimensional Analytical Solution for a Partially Vegetated Compound Channal Flow
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摘要: 运用涡粘模型理论对部分植被化复式河道的水流水深平均流速和边壁切应力分布进行了求解.通过对水流微元体进行纵向受力分析建立相应的控制微分方程,其中植被对水流的影响归结为拖曳力项.同时将复式渠道划分为3个子区域,通过联立求解各区域微分方程中的定解系数,最终得到均匀流的条件下各区水深平均流速的横向分布的解析解.在获得水深平均流速的横向分布后,可进一步给出对泥沙输移有重要影响的河床切应力的横向分布.通过与试验测得的资料比较,表明给出的解析解能够为工程设计提供足够精度的水力特性的预报.Abstract: The theory of eddy viscosity model is applied to the study of the flow in compound charurel which was partially vegetated.The governing equation was constituted by analyzing the longitudinal forces acted on the unit volume where the effect of the vegetation to the flow is considered as the drag force item.The compound channel was divided into 3 sub-regions in transverse direction,and the weffcients in every region's differential equations were solved simultaneously.Thus the analytical solulion of the transverse distribution of the depth-averaged velocity for uniform flow in partially vegetated compound channel is got.The results can also be used to predict the transverse distribution of the bed shear stress which has an important effect on the transportation of sediment.by comparing the analytical results with the measured data,the analytical solution was prnved to be sufficiently accurate to predict most hydraulic features for engineering design purpose.
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Key words:
- compound channel /
- depth-averaged velocity /
- drag force /
- eddy viscosity model /
- analytical solution /
- vegetation
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[1] Wilson C A,Stoesser M E,Bates T,et al.Open channel flow through different forms of submerged flexible vegetation[J].J Hydraulic Engineering,ASCE,2003,129(11):847-853. doi: 10.1061/(ASCE)0733-9429(2003)129:11(847) [2] Jarvela J.Effect of submerged flexible vegetation on flow structure and resistance[J].Journal of Hydrology,2005,307(1/4):233-241. doi: 10.1016/j.jhydrol.2004.10.013 [3] Carollo F G,Ferro V,Termini D.Flow velocity measurements in vegetated channels[J].J Hydraulic Engineering ASCE,2002,128(7):664-673. doi: 10.1061/(ASCE)0733-9429(2002)128:7(664) [4] Kouwen N. Fathi-Moghadam M.Friction factors for coniferous trees along rivers[J].J Hydraulic Engineering,2000,126(10):732-740. doi: 10.1061/(ASCE)0733-9429(2000)126:10(732) [5] Hsieh T. Resistance of cylinder piers in open-channel flow[J].J of Hydraulic Div,ASCE,1964,90(HY1):161-173. [6] Li R M, Shen H W. Effect of tall vegetation on flow and sediment[J].J of Hydraulic Div,ASCE,1973,99(5):793-813. [7] Pasche E, Rouve G. Overbank Flow with vegetatively Roughened flood plains [J].J of Hydraulic Div, ASCE,1985,119(9):1262-1278. [8] Shiono K, Knight D W.Two dimensional analytical solutions for a compound channel[A].In:Iwasa Y,Tamai N,Wada A,Eds.Proceedings of the third International Symposium on Refined Flow Modeling and Turbulence Measurements[C].Tokyo, Japan:University Academy Press,1988, 503-510. [9] Shiono K,Knight D W. Turbulent open channel flows with variable depth across the channel[J].J Fluid Mech,1991,222(1):617-646. doi: 10.1017/S0022112091001246 [10] Fischer-Antze T, Stoesser T,Bates P,et al.3D numerical modelling of open-channel flow with submerged vegetation[J].J Hydraulic Research,2001,39(3):303-310. doi: 10.1080/00221680109499833
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