Parameshwari Kattel

Some novel aspects of two-phase debris flows


Debris flows and avalanches are highly destructive natural hazards which occur in complicated mountain topography. Himalayan mountains are very much prone to slope failures, and the resulting geophysical mass flows are often causing damages, mainly in the rainy seasons. The study of their dynamics is crucial for preventive as well as mitigative measures. Although there are many research works that have been carried in the past decades and recent years, there is a lot yet to be done in terms of dimensions, mechanics and phase-interactions.

We emphasize on the application of the high-resolution numerical scheme to simulate three-dimensional and real two-phase debris flows down more general channels and slopes. The simulation results provide as output, the evolution of the both phases - the solid particles and fluid, geometrical evolution of the debris bulk as a whole, the interaction of the flow with obstacles, the associated dynamic and stagnant pressures, the dynamics of material influenced by the obstacle, and the boundary tractions along the slip surface and at the faces of the obstacle. Further, the diffusion of solid and fluid phases, and the phase-localizations in different flow regimes will be studied in detail. Including other pioneering and advanced models [1-9, 11], this will be achieved by employing the general two-phase physical-mathematical mass flow model [10]. Results will be validated, the model and simulation tools will be improved. Analytical solutions for applicable flow configurations will be constructed. Moreover, the parameter sensitivity analysis will also be carried out to isolate physically and geometrically negligible parameters.

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