Unsteady heat transfer in non-axisymmetric Homann stagnation-point flows

Abstract

An analysis is carried out to study the unsteady non-axisymmetric Homann’s stagnation-point flow and heat transfer of an incompressible viscous fluid over a rigid plate in the presence of time-dependent free stream. The temperature of the plate is assumed to be higher than the ambient fluid temperature. Using similarity variables, the governing partial differential equations are transformed into nonlinear ordinary differential equations. These equations are then solved numerically using fourth-order Runge–Kutta method with shooting technique. The effects of the shear-to-strain rate ratio parameter $\gamma$ ($\gamma =b/a$ where a and b are the strain rate and shear rate of the stagnation-point flow, respectively) and the unsteadiness parameter $\lambda$ on wall shear stress parameters, dimensionless velocities, rate of heat transfer at the wall and dimensionless temperature are analysed. It is found that the large-$\gamma$ asymptotes do not depend on the parameter $\lambda$.