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

来源：Journal of Mountain Science, 2018, 15(5): 1071-1089.

DOI：10.1007/s11629-018-4886-5

• Debris flows
• Quasi single-phase mixture model
• Stresses due to fluctuations
• Well-balanced

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 - epsilon 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.

• 出版日期2018-5
• 单位中国科学院、水利部成都山地灾害与环境研究所; 水资源与水电工程科学国家重点实验室; 武汉大学; 北京理工大学