A quasi single-phase model for debris flows and its comparison with a two-phase model

作     者：XIA Chun-chen LI Ji CAO Zhi-xian LIU Qing-quan HU Kai-heng 

作者机构：State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Department of Mechanics School of Aerospace Engineering Beijing Institute of Technology Institute of Mountain Hazards and Environment Chinese Academy of Sciences 

出 版 物：《Journal of Mountain Science》 (山地科学学报（英文）)

年 卷 期：2018年第15卷第5期

页      面：1071-1089页

核心收录：

学科分类：08[工学] 0837[工学-安全科学与工程] 

基　　金：funded by Natural Science Foundation of China(Grants Nos.51279144 and 11432015) 

主　　题：Debris flows Quasi single-phase mixturemodel Stresses due to fluctuations Well-balanced 

摘      要：A depth-averaged quasi single-phase mixture model is proposed for debris flows over inclined bed slopes based on the shallow water hydrosediment-morphodynamic theory with multi grain sizes. The stresses due to fluctuations are incorporated based on analogy to turbulent flows, as estimated using the depth-averaged k-? turbulence model and a modification component. A fully conservative numerical algorithm, using wellbalanced slope limited centred scheme, is deployed to solve the governing equations. The present quasi single-phase model using four closure relationships for the bed shear stresses is evaluated against USGS experimental debris flow and compared with traditional quasi single-phase models and a recent physically enhanced two-phase model. It is found that the present quasi single-phase model performs much better than the traditional models, and is attractive in terms of computational cost while the two-phase model performs even better appreciably.