Numerical Study of Flow and Heat Transfer around Single Smooth or Dimpled Sphere in the Square Channel

The purpose of present paper is to investigate the flow and heat transfer characteristics of single smooth or dimpled sphere in the square channel by numerical simulation. Three-dimensional Navier-Stokes equations and SST k-ω turbulence model are adopted for the simulations. The effects of channel to particle diameter ratio and particle surface shape were discussed and presented in the present paper. It is found that, with the same inlet velocity and particle surface shape, when the ratio of channel to particle diameter is less than 4, as W/D decreases, the drag coefficient and Nusselt number increases rapidly. In addition, compared with smooth sphere particles, the presence of dimples decrease flow drag. Furthermore, at Re=29000, although there is little difference of Nusselt number between smooth and dimpled particles, the surface heat transfer characteristics of different particles are quite different.