On The Effect of Flow Direction on Mixed Convection Around Heated Circular Cylinder

Abstract

A numerical investigation of laminar mixed convection around horizontal isothermal cylinder is presented. The free stream direction varies between the vertically upward (assisting flow) and vertically downward (opposing flow). The governing equation in terms of the stream function, vorticity and temperature are expressed in a body-fitted coordinate system and solved numerically by explicit method. Results are presented for Reynolds number from 20 to 300 with Grashof numbers from 0 to 120000. The Prandtl number was kept constant at 0.7. Correlation for the average Nusselt number around the cylinder in the forced and mixed convection regime is suggested. Comparison with previous theoretical and experimental results shows good agreement. It was established that the maximum heat transfer from cylinder occurs in case of assisting flow.