Numerical modeling of unsteady gas-particle flows around rectangles inside channels

This paper presents numerical solutions for gas-particle flows around rectangles inside two-dimensional channels. Vortex shedding frequencies are seen to compare well with the results of a wind tunnel experiment. Trajectories of individual physical particles through this highly unsteady flow are presented for varying combinations of Stokes number and gravitational force. The numerical scheme utilizes an explicit Leith-type of temporal differencing and quadratic upwind differencing for convection. A fast direct method is used to solve the Poisson equation for pressure at each time step. An infinite-to-finite mapping is employed near the downstream boundary of the computational mesh. This enables a fully-developed parabolic velocity profile to be prescribed at the mesh exit. The computational results indicate the presence of possible surface erosion problems for some combinations of the tested parameters.