An analysis of combined free and forced convection heat transfer from a horizontal circular cylinder to a transverse flow

Combined free and forced convection heat transfer from a horizontal circular cylinder to a transverse flow is analysed for the case when the forced flow is either in the direction of the free convection flow (parallel flow) or in the direction opposite to it (counter flow). The problem is solved for two cases: (1) a specified surface temperature variation and (2) a specified wall heat flux variation along the circumference. A coordinate perturbation method is used to transform the governing set of partial differential equations into a system of ordinary differential equations, which are solved by numerical methods. The numerical work is done for the boundary conditions of constant surface temperature and constant wall heat flux. The variation of local heat transfer coefficient and wall shear stress along the circumference up to the point of separation and velocity and temperature profiles in the boundary layer are obtained for varying values of the governing parameters Gr/Re<SUP>2</SUP> in the constant temperature case (or ̅Gr/Re<SUP>2</SUP> in the constant heat flux case) and Pr