Graetz Problem in Curved Square Channels

Abstract

Thermal entrance region heat transfer problem in curved square channels is solved by a numerical method for the two basic thermal boundary conditions of constant wall temperature and uniform wall heat flux by including the curvature ratio effect in the formulation as an independent parameter. Solutions are obtained for Pr = 0.1, 0.7, 5, 10.05 and 500 and Dean numbers ranging from 0–488. Local Nusselt number results are qualitatively similar to those reported in the literature for the case of curved circular pipes. The numerical results for the asymptotic Nusselt number agree well with the only experimental data available for the case of uniform wall heat flux. A correlation equation for the asymptotic Nusselt number is proposed.