Evaluation of Reynolds-averaged Navier-Stokes turbulence models in open channel flow over salmon redds  

作　　者：Bishal Bhattarai Brandon Hilliard Daniele Tonina William J.Reeder Ralph Budwig Benjamin T.Martin Tao Xing 

机构地区：[1]Department of Mechanical Engineering,University of Idaho,Moscow,USA [2]Center for Ecohydraulics Research,University of Idaho,Boise,USA [3]Institute for Biodiversity and Ecosystem Dynamics,University of Amsterdam,Amsterdam,The Netherlands [4]Hamm School of Engineering,University of Mary,Bismarck,USA

出　　处：《Journal of Hydrodynamics》2024年第4期741-756,共16页水动力学研究与进展B辑（英文版）

基　　金：supported by the California State Water Resources Control Board(Grant No.19-028-300);the National Science Foundation(Grant No.2043382).

摘　　要：This study evaluates computational fluid dynamics(CFD)turbulence closures for Reynolds-averaged Navier-Stokes(RANS)equations against experimental data to model complex open channel flows,like those occurring over dune-shaped salmon spawning nests called"redds".Open channel flow complexity,characterized by near-bed turbulence,adverse pressure,and free surfaces,requires suitable turbulence closure capable of capturing the flow structure between streambed and water surface.We evaluated three RANS models:Standard k-,shear-stress transport(SST)k-@and realizable k-,along with four wall treatments for the realizable k-:Standard,and scalable wall functions,enhanced wall treatment,and an unconventional closure combining standard wall function with near-wall mesh resolving the viscous sublayer.Despite all models generally capturing the bulk flow characteristics,considerable discrepancies were evident in their ability to predict specific flow features,such as flow detachments.The realizable k-model,with standard wall function and mesh resolving viscous sublayer,outperformed other closures in predicting near-wall flow separations,velocity fields,and free surface elevation.This realizable k-model with a log-layer resolved mesh predicted the free surface elevation equally well but lacked precision for near-wall flows.The SST k-@model outperformed in predicting turbulent kinetic energy and provided better predictions of the near-boundary velocity distributions than realizable k-closure with any of the conventional wall treatments but overestimated the separation vortex magnitude.The standard k-o model also overestimated near-wall separation.This study highlights the variability in accuracy among turbulence models,underlining the need for careful model selection based on specific prediction regions.

关 键 词：Salmon redd numerical simulation turbulence models volume of fluid(VOF) 

分 类 号：TV133[水利工程—水力学及河流动力学]