The heat transfer coefficient, h, captures both heat conduction and flow effects. Thus, in the case when flow is negligible, this coefficient would measure only the effect of conduction. This can be...

The heat transfer coefficient, h, captures both heat conduction and flow effects. Thus, in the case when flow is negligible, this coefficient would measure only the effect of conduction. This can be demonstrated by solving a pure conduction problem. A heated sphere at temperature Ts is in a large, motionless fluid at temperature T 00 far from the sphere. Find the expression for the heat transfer coefficient over this sphere surface in terms of its diameter, D, and the thermal conductivity of the fluid, k. (Hint: Starting from the governing equation, set up the heat conduction problem (without bulk flow or convection)for the fluid in spherical coordinates with temperature Ts at a radius D/ 2 and temperature T 00 at infinity.)