水科学与水工程2009，Vol.2Issue(3)：13-26,14.DOI:10.3882/j.issn.1674-2370:2009.03.002
3-D hybrid LES-RANS model for simulation of open-channel T-diversion flows
3-D hybrid LES-RANS model for simulation of open-channel T-diversion flows
Jie ZHOU 1Cheng ZENG2
作者信息
- 1. College of Environmental Science and Engineering,Hohai University,Nanjing 210098,P.R.China
- 2. Department of Civil and Structural Engineering,Hong Kong Polytechnic University,
Hong Kong,P.R.China
- 折叠
摘要
Abstract
The study of flow diversions in open channels plays an important practical role in the design and management of open-channel networks for irrigation or drainage.To accurately predict the mean flow and turbulence characteristics of open-channel dividing flows,a hybrid LES-RANS model,which combines the large eddy simulation (LES) model with the Reynolds-averaged Navier-Stokes (RANS) model,is proposed in the present study.The unsteady RANS model was used to simulate the upstream and downstream regions of a main channel,as well as the downstream region of a branch channel.The LES model was used to simulate the channel diversion region,where turbulent flow characteristics ate complicated.Isotropic velocity fluctuations were added at the inflow interface of the LES region to trigger the generation of resolved turbulence.A method based on the virtual body force is proposed to impose Reynolds-averaged velocity fields near the outlet of the LES region in order to take downstream flow effects computed by the RANS model into account and dissipate the excessive turbulent fluctuations.This hybrid approach saves computational effort and makes it easier to properly specify inlet and outlet boundary conditions.Comparison between computational results and experimental data indicates that this relatively new modeling approach can accurately predict open-channel T-diversion flows.关键词
hybrid LES-RANS model/open-channel flow/T-diversion/turbulence modelingKey words
hybrid LES-RANS model/open-channel flow/T-diversion/turbulence modeling分类
建筑与水利引用本文复制引用
Jie ZHOU,Cheng ZENG..3-D hybrid LES-RANS model for simulation of open-channel T-diversion flows[J].水科学与水工程,2009,2(3):13-26,14.
