Average effects of forced convection over a flat plate with an unheated starting length

Parallel flow over a flat plate with an unheated starting length is a good approximation of actual conditions in many engineering applications. A single general closed-form analytical solution for the average heat transfer coefficient for either an isothermal or isoflux boundary condition and for either laminar or turbulent flow is presented. For a smooth surface experiencing a uniform heat flux, the average surface temperature is also of interest. Individual analytical expressions are presented for the average temperature of a flat plate with an isoflux boundary condition for both laminar and turbulent flow. These expressions provide an expeditious means of determining average conditions for convective flow over a partially heated flat plate.