Thermal transfer in turbulent gas streams: Temperature distribution in boundary flows about spheres



A knowledge of the temperature distribution about bodies of revolution, and more particularly about spheres, is of interest in connection with many problems associated with thermal and material transport. The present investigation involved measurements of the temperature distribution in the boundary flows about a 0.5-in. porous sphere and 0.5-in. and 1.0-in. silver spheres. The measurements were made in an air stream at velocities between 4 and 32 ft./sec. under conditions of shear flow, as well as at various positions in the wake of a perforated grid. From these measurements the thickness of the thermal boundary layer was established as a function of polar angle and conditions of flow. The experimental data were correlated upon the assumption that the normalized temperature in the boundary flow is a single-valued function of the position in the thermal boundary layer. It appeared that this simple assumption described the experimental data within the uncertainties of measurement and that the Blasius function provided a reasonable description of the relationship of the normalized temperature to the relative position in the thermal boundary layer.