Thermal radiation effects on free convection over a rotating axisymmetric body with application to a rotating hemisphere

Abstract

This paper deals with the interaction of thermal radiation with free convection, laminar boundary-layer flow past a heated rotating axisymmetric round-nosed body of uniform surface temperature. The fluid considered is a gray, absorbing-emitting but nonscattering medium, and Rosseland approximation is used to describe the radiative heat flux. The difficulty of having a unified mathematical treatment of this problem is due to the nonsimilarity nature of the governing equations arising from the buoyant force-field and the transverse curvature of the body. The important parameters of this problem are the Planck number, R_d, the buoyancy parameter, λ, and the wall to free stream temperature ratio, θ_w. Numerical solution of the boundary-layer equations are performed using the Keller-box method as well as the local nonsimilarity method. The theory is applied to a rotating hemisphere for a gas with Prandtl number of 0.72. The effects of the parameters λ, R_d and θ_w are shown on the velocity and temperature profiles, as well as on the local skin friction coefficient and local rate of heat transfer.