Experiments to determine the local convection heat transfer coefficient for uniform flow normal to a heated circular disk have yielded a radial Nusselt number distribution of the form where both n and a are positive. The Nusselt number at the stagnation point is correlated in terms of the Reynolds (ReD VD/ ) and Prandtl numbers Obtain an expression for the average Nusselt number, D D/k, corresponding to heat transfer from an isothermal disk. Typically, boundary layer development from a stagnation point yields a decaying convection coefficient with increasing distance from the stagnation point. Provide a plausible explanation for why the opposite trend is observed for the disk.