Effective Fluid Temperature for Heat Transfer by Laminar Free Convection

Abstract

With the use of integrated momentum and energy equations for the boundary layer, a calculation was carried out for the heat transfer to the laminar free-convection flow on a vertical flat plate submerged in a fluid with vertically ununiform temperature. The average heat transfer coefficients applicable to the cases of free convection in the fluid of uniform temperature was shown to be applied also to the present case, provided that the fluid temperature at (0.2 to 0.3)×(plate height) from the bottom end was taken as the effective fluid temperature. This conclusion was fairly ascertained by experiments.