부산대학교 도서관

Here we present a three-dimensional fluid dynamic solver that simulates debris flows as a mixture of two phases (gravel and fine material suspension) with a third unmixed phase representing the air and the free surface. We link all rheological parameters to the material composition, i.e., to water content, clay content and mineral composition, content of sand and gravel, and the gravel's friction angle; the user must specify only a single free model parameter. The Volume-Of-Fluid (VOF) approach is used to combine the three phases into a single cell-averaged Navier-Stokes equation for incompressible flow, based on code adapted from standard solvers of the Open-Source CFD software OpenFOAM. We present a stable implementation of a Coulomb-Viscoplastic model that represents the pressure-dependent flow behavior of the granular phase, and a Herschel-Bulkley representation of the interstitial fluid. The VOF method saves computational costs compared to drag-force based multiphase models. Thus depthaveraging is not necessary and complex three-dimensional flow structures can be simulated. [ABSTRACT FROM AUTHOR]