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

• 来源期刊: 山地科学学报（英文版）
• 年，卷（期）: 2018,（5）
• 页码范围: 1071-1089
• 页数: 19页
• 语种: 英文

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-ε turbulence model and a modification component.A fully conservative numerical algorithm,using well-balanced 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.