Vol15 No.5: 1071-1089
【Title】A quasi single-phase model for debris flows and its comparison with a two-phase model
【Author】XIA Chun-chen1; LI Ji1; CAO Zhi-xian1; LIU Qing-quan2; HU Kai-heng3
【Addresses】1 State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China; 2 Department of Mechanics, School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081, China; 3 Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China
【Corresponding author】XIA Chun-chen
【Citation】Xia CC, Li J, Cao ZX, et al. (2018) A quasi single-phase model for debris flows and its comparison with a two-phase model. Journal of Mountain Science 15(5). https://doi.org/10.1007/s11629-018-4886-5
【Abstract】A depth-averaged quasi single-phase mixture model is proposed for debris flows over inclined bed slopes based on the shallow water hydro-sediment-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 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.
【Keywords】Debris flows; Quasi single-phase mixture model; Stresses due to fluctuations; Well-balanced