Rapid motions of free-surface avalanches down curved and twisted channels and their numerical simulation.
This paper presents a new model and discussions about the motion of avalanches from initiation to run-out over moderately curved and twisted channels of complicated topography and its numerical simulations. The model is a generalization of a well established and widely used depth-averaged avalanche model of Savage & Hutter and is published with all its details in Pudasaini & Hutter (Pudasaini & Hutter 2003 J. Fluid Mech. 495, 193-208). The intention was to be able to describe the flow of a finite mass of snow, gravel, debris or mud, down a curved and twisted corrie of nearly arbitrary cross-sectional profile. The governing equations for the distribution of the avalanche thickness and the topography-parallel depth-averaged velocity components are a set of hyperbolic partial differential equations. They are solved for different topographic configurations, from simple to complex, by applying a high-resolution non-oscillatory central differencing scheme with total variation diminishing limiter. Here we apply the model to a channel with circular cross-section and helical talweg that merges into a horizontal channel which may or may not become flat in cross-section. We show that run-out position and geometry depend strongly on the curvature and twist of the talweg and cross-sectional geometry of the channel, and how the topography is shaped close to run-out zones.
Pudasaini
Shiva P
SP
Department of Mechanics--AG III, Darmstadt University of Technology, Germany. pudasain@mechanik.tu-darmstadt.de
Wang
Yongqi
Y
Hutter
Kolumban
K
D045424:Complex Mixtures / Q000032:analysis*; D003198:Computer Simulation; D004190:Disasters; D017276:Friction; D005844:Geology / Q000379:methods*; D008962:Models, Theoretical; D009038:Motion; D012212:Rheology / Q000379:methods*; D013314:Stress, Mechanical
D045424:Complex Mixtures