ABSTRACT
Of the three modes of heat transfer (conduction, convection, and radiation), the convection mode has the most varied applications. Convection is the result of two energy transfer mechanisms: fluid motion and molecular motion. The molecular motion at the heat transfer interface is due to conduction through the stagnant thermal boundary layer. Heat transfer through this layer is based upon Fourier's law,1 AT = qL/k Ac. In convective heat transfer, the engineer is faced with estimating the heat transfer coefficient, hc, for a surface. Usually, this coefficient comes from texts of empirical formulas which are based on actual experiments and observations. We cannot calculate the heat transfer coefficient exactly because we can only analytically solve the differential equations governing convection for the simplest flows and geometries. The empirical equations for the Nusselt number2 are often tedious and complex.
