Numerical Experiments on the Study of Mixed Convection Flow in Cylindrical Geometry

Steady, laminar flow of an incompressible fluid with mixed convection over an isothermal circular cylinder is considered. The governing full nonlinear Navier-Stokes equations with energy equation are solved by using a high-accuracy finite difference scheme in cylindrical polar coordinates. The results are discussed in detail for 5 <= Re <= 40, 0.7 <= Pr <= 7, and 0 <= Ri <= 4 and the results are in agreement with the experimental and other computed data. An increase in the mixed convection parameter leads to reduction of the drag coefficient. The fluid with higher Pr generates vortices that destabilize the flow. The local Nu for the mixed convection cases are higher than the pure forced convection counterparts. The normalized mean Nusselt number (N-m) does not significantly change for flows with very small Richardson numbers. However, for larger Ri, it increases linearly with Ri.