Motion of micro-particles in channel flow

The motion of micro-particles in channel flow was investigated using the DNS method for Re=3300 (based on center velocity and half channel width). The calculations used the fractional projection method to directly solve the Navier–Stokes equations, and the explicit third-order Runge–Kutta method for the time integration. A higher order finite difference scheme was used to discretize the fluid dynamics equations. The numerical results provided the two-phase flow field in the near-wall region with micro-particles. The simulation results showed that particles with Stokes number on the order of 0.1 tend to congregate near the wall while the micro-particles 1 μm in diameter distribute homogeneously in the whole flow field. Simulations of micro-particulate matter movement using the κ– turbulence model applied to the same problem as the DNS analysis showed that the turbulence model could not accurately predict the micro-particle motion in the turbulent flow near the wall, with higher particle concentrations close to the centerline and lower concentrations near the wall.