Experimental and numerical study of the subaqueous granular dam-break flow

Subaqueous granular flow is of great interesting in geophysics flow and coastal engineering. Despite its simple configuration, the underwater granular dam-break problem involves many mechanisms in a single event and thus could serve as a benchmark case for different numerical models. Here we carried out a series of experiments using the refractive index matching technique to obtain the motion of the spherical particle and the velocity field of the ambient liquid simultaneously. Then a three-dimensional two-phase continuum model is developed based on SedFOAM to simulate this high concentration granular flow. It is found that this dam-break granular flow could be divided into three regions including a liquid flow controlled surface, a slide dominated shallow layer beneath it, and a particle solid phase at the bottom. Thus, the dividing of the granular pressure, i.e. the permanent contact-induced component and the collision-induced component, is necessary for the numerical model to correctly represent the experimental data.