The effect of free stream turbulence on heat and momentum transfer to axisymmetric bodies

Effects of free-stream turbulence on heat and momentum transfer to axisymmetric bodies have been investigated. The flow was assumed to be compressible with variable viscosity. Fluid density and viscosity were taken to be proportional to the inverse of enthalpy and enthalpy to same power, respectively, with the exponent equal to 0.5, 0.7, and 1.0. Results were obtained for a wide range of free-stream turbulence intensity and Reynolds number. The results show that wall heat transfer and skin friction can be greatly magnified due to free-stream turbulence. Skin friction was found to increase with increasing ratio of wall to boundary-layer-edge enthalpy where the effect of variable density ratio outweighs the effect of the effective skin-friction coefficient. On the other hand, Nusselt number can either increase or decrease with enthalpy ratio, depending on the value of the viscosity exponent. Results were compared with low-speed experimental data, and good agreement was found.