COMPUTATION OF FLOW AND HEAT TRANSFER AROUND A VERTICAL DISCRETE PROTRUDING HEATER USING AN OPERATOR-SPLITTING ALGORITHM

Abstract

Steady mixed convection around a heated block placed in a vertical channel is numerically studied. The block aspect ratio is taken as I / 3. The following range of parameters has been considered: 200 ≤ Re.≤ 1000 and Gr = 0 and 10⁵. The governing equations have been solved using an operator-splitting technique. This method splits the equations into advection, diffusion, and source terms and solves each component in an implicit time-marching scheme as accurately as possible. The results obtained using this method have been compared with those obtained using the second upwind procedure for the advection terms. The overall distribution of the local flow quantities around the heater is seen to be quite similar for the two methods. However, the average Nusselt number computed using the two methods has significant differences. The operator-splitting method shows that the mixed convection Nusselt number can fall below that of the forced convection value for a certain range of parameters. A comparison of CPU times also shows the operator-splitting method to be superior to upwinding.