Transport at large downstream distances in mixed convection flow adjacent to a vertical uniform-heat-flux surface

Abstract

A perturbation analysis of mixed convection flow over a vertical semi-infinite surface with uniform heat flux is presented. A matched asymptotic expansion technique is used to construct inner and outer expansions including, for the first time, both mixed convection and higher-order boundary layer effects. It is shown that these effects must be simultaneously included to obtain consistent higher-order approximations to mixed convection boundary layer flow at large downstream distances. Numerical calculations are presented for Pr = 0.733 and 6.7 which indicate the relative magnitudes of mixed convection and non-boundary layer effects. In addition, new experimental measurements of surface heat transfer rates and velocity and temperature profiles are presented for mixed convection flow adjacent to a vertical uniformheat-flux surface in air. The measured profiles are found to be in excellent agreement with those predicted by the analysis. The predicted variation of the Nusselt number is also seen to agree well with the values inferred from the measurements.