Numerical modeling of the propagation and morphological changes of turbidity currents using a cost-saving strategy of solution updating  

作　　者：Peng Hu Yue Li 

机构地区：[1]Ocean College,Zhejiang University,Zhoushan Campus,316021,China

出　　处：《International Journal of Sediment Research》2020年第6期587-599,共13页国际泥沙研究（英文版）

基　　金：This research is supported by the National Key Research and Development Program of China(No.2017YFC0405400);the National Natural Science Foundation of China(Nos.11772300,11872332,11402231);Zhejiang Natural Science Foundation(No.LR19E090002).

摘　　要：Existing layer-averaged numerical models for turbidity currents have mostly adopted the global minimum time step(GMiTS)for solution updating,which confines their computational efficiency and limits their attractiveness for field applications.This paper presents a highly efficient layer-averaged numerical model for turbidity currents by implementing the combined approach of the local graded-time-step(LGTS)and the global maximum-time-step(GMaTS).The governing equations are solved for unstructured triangular meshes by the shock-capturing finite volume method along with a set of well-balanced evaluations of the numerical flux and geometrical slope source terms.The quantitative accuracy of the model,given reasonably estimated empirical and model parameters(e.g.,bed friction,water entrainment,sediment deposition and erosion coefficients),is demonstrated by comparing the numerical solutions against laboratory data of the current front positions and deposition profiles,as well as field data of the current front positions.The improved computational efficiency is demonstrated by comparing the computational cost of the present model against that of a traditional model that uses a GMiTS.For the present simulated cases,the maximum reduction of the computational cost is approximately 80%(e.g.,a simulation that cost 1 h before will only require 12 min with the new model).

关 键 词：Turbidity currents Numerical modeling Computational efficiency Time step 

分 类 号：TV14[水利工程—水力学及河流动力学]