Mathematical Modeling and Simulation of: A Two-phase and Three-dimensional Submarine Landslide and a Fluid Reservoir

Abstract: Gravitational flows like submarine and subaerial landslides and debris avalanches may generate tsunami waves as they hit some water body such as ocean, reservoir, lake or fjord. Here, the general two-phase debris flow model proposed by Pudasaini (2012) is applied to study submarine and subaerial debris flows, and the tsunami generated by the debris impact at reservoirs. The model, which includes three fundamentally new and dominant physical aspects such as enhanced non-Newtonian viscous stress, virtual mass, and generalized drag, constitutes the most generalized two-phase physical-mathematical mass flow model to date. Three-dimensional, high-resolution simulation results are presented in case when a real two-phase debris mass hits a fluid reservoir that consists of different solid concentrations. Simulations are performed for different time slices and different parameter values. An innovative formulation is employed that provides an opportunity, within a single framework, to simultaneously simulate the sliding two-phase debris/landslide, reservoir, debris impact at reservoir, tsunami generation, amplification and propagation, mixing and separation between the solid and fluid phases (Kafle, 2014). The results show formation and propagation of very special solid- and fluid-structures in the reservoir, propagation of the submarine debris mass and turbidity currents, tsunami impacts at coastal lines, and complex interactions between the subaerial, tsunami and submarine debris waves, and reservoir walls. The simulation results show that th