Shallow sediment transport flow computation using time-varying sediment adaptation length  

作　　者：Jaan Hui PU Khalid HUSSAIN Song-dong SHAO Yue-fei HUANG 

机构地区：[1]School of Engineering and Informatics,University of Bradford West Yorkshire BD7 1DP,UK.Lecturer [2]School of Engineering,University of Bradford West Yorkshire BD7 1 DP,UK.Head [3]Department of Civil and Structure Engineering,University of Sheffield Sheffield S1 3JD,UK Senior Lecturer [4]State Key Laboratory of Hydro-Science and Engineering,Tsinghua University

出　　处：《International Journal of Sediment Research》2014年第2期171-183,共13页国际泥沙研究（英文版）

基　　金：the support of the National Natural Science Foundation of China NSFC(Grant Number 20101311246);Major State Basic Research Development Program(973 program) of China(Grant Number 2013CB036402);Open Fund of the State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University(Grant Number SKLH-OF-1103)

摘　　要：Based on the common approach,the adaptation length in sediment transport is normally estimated astemporally independent.However,this approach might not be theoretically justified as the process of reaching the sediment transport equilibrium stage is affected by the flow conditions in time,especially for fast moving flows,such as scour-hole developing flows.In this study,the two-dimensional（2D） shallow water formulation together with a sediment continuity-concentration（SCC） model were applied to flow with mobile sediment boundary.A timevarying approach was proposed to determine the sediment transport adaptation length to simulate the sediment erosion-deposition rate.The proposed computational model was based on the Finite Volume（FV） method.The Monotone Upwind Scheme of Conservative Laws（MUSCL）-Hancock scheme was used with the Harten Lax van Leer-contact（HLLC） approximate Riemann solver to discretize the FV model.In the flow applications of this paper,a highly discontinuous dam-break,fast sediment transport flow was used to calibrate the proposed timevarying sediment adaptation length model.Then the calibrated model was further applied to two separate experimental sediment transport flow applications documented in the literature,i.e.a highly concentrated sediment transport flow in a wide alluvial channel and a sediment aggradation flow.Good agreement with the experimental data were obtained with the proposed model simulations.The tests prove that the proposed model,which was calibrated by the discontinuous dam-break bed scouring flow,also performed well to represent rapid bed change and steady sediment mobility conditions.Based on the common approach,the adaptation length in sediment transport is normally estimated astemporally independent.However,this approach might not be theoretically justified as the process of reaching the sediment transport equilibrium stage is affected by the flow conditions in time,especially for fast moving flows,such as scour-hole developing flows.In this study,the two-dimensional（2D） shallow water formulation together with a sediment continuity-concentration（SCC） model were applied to flow with mobile sediment boundary.A timevarying approach was proposed to determine the sediment transport adaptation length to simulate the sediment erosion-deposition rate.The proposed computational model was based on the Finite Volume（FV） method.The Monotone Upwind Scheme of Conservative Laws（MUSCL）-Hancock scheme was used with the Harten Lax van Leer-contact（HLLC） approximate Riemann solver to discretize the FV model.In the flow applications of this paper,a highly discontinuous dam-break,fast sediment transport flow was used to calibrate the proposed timevarying sediment adaptation length model.Then the calibrated model was further applied to two separate experimental sediment transport flow applications documented in the literature,i.e.a highly concentrated sediment transport flow in a wide alluvial channel and a sediment aggradation flow.Good agreement with the experimental data were obtained with the proposed model simulations.The tests prove that the proposed model,which was calibrated by the discontinuous dam-break bed scouring flow,also performed well to represent rapid bed change and steady sediment mobility conditions.

关 键 词：Finite volume model Harten Lax van Leer-contact solver Monotonic upwind scheme Sediment transport Shallow water model Time-varying sediment adaptation length 

分 类 号：TV14[水利工程—水力学及河流动力学]