Microscopic investigation of Rayleigh-Taylor instability in a sedimenting suspension

We investigate Rayleigh-Taylor instability in a sedimenting suspension by the numerical calculation of the microscopic particle and fluid dynamics. Because of the availability of very fast and massively parallel machines of the lattice Boltzmann method combined with the immersed boundary method, the GPU accelerates particle-based mesoscale hydrodynamic simulations. When we use the immersed boundary-lattice Boltzmann method, we observe the boundary slips on the solid-liquid interface that cause the significant error in the computation of the suspension system. In order to solve the velocity slip problem, we apply two relaxation times collision operator to the lattice Boltzmann method, and demonstrate that our numerical method based on the implicit correction method with the two relaxation times succeeds in preventing the flow penetration through the solid surface as well as unphysical velocity slips.