The two-dimensional thermal problem due to relative motion of a medium
and a suddenly activated circular heat source is solved for several b
oundary conditions. The solutions can be interpreted as for a moving h
eat source in a stationary medium or a medium moving past a stationary
heat source. Uniform and non-uniform temperature, and uniform and non
-uniform heat flux boundary conditions are considered. The effect of v
elocity and radial direction on the temperature distribution is examin
ed. Average, steady-state Nusselt numbers are derived. The transient r
esponse of a continuous line source is obtained as a limiting case of
the prescribed heat flux solution.