NUMERICAL SIMULATIONS OF NON-NEWTONIAN GEOPHYSICAL FLOWS USING SMOOTHED PARTICLE HYDRODYNAMICS (SPH) METHOD:A RHEOLOGICAL ANALYSIS

摘要

This paper presents computational results for two-dimensional (2-D) simulations of geophysical flows using the Smoothed Particle Hydrodynamics (SPH) method. The basic equations solved are the incompressible mass conservation and Navier-Stokes equations, and the discretization is carried out using the SPH method. The simulations are carried out for two problems. The first problem involved a 2-D dam-break problem with mud flow. The second problem involved non-Newtonian flow of deformable landslide on a mild slope. In both the simulations, the flow is assumed to be incompressible. In the present study, the mud flow materials are represented as non-Newtonian fluids with a Bingham model. The effects of the rheological formulation are assessed for the predicted mudflow shape. The simulation results are compared with the experimental data available in open literature. The velocity profiles and the free surface shape are in good agreement with the experimental data. To distinguish between the non-Newtonian model simulations and the Newtonian model, the dam-break simulations were also carried out using water and Newtonian models. The simulations reveal several distinctive flow features between the Newtonian and non-Newtonian approaches. The results of the simulations are of engineering interest in mitigation of natural hazards such as debris flows.