Free convection effects on the flow past a vertical porous plate set impulsively into motion with negligible dissipation

Abstract

The flow induced by the impulsive motion of a vertical porous plate is analysed under the following assumptions: (i) that the flow is incompressible, (ii) that the suction normal to the plate is constant, (iii) that the temperature difference between the plate and the free-stream,T _w −T _∞, is large enough for free convection currents to flow, and (iv) that the flow is slow enough for dissipation to be neglected. By employing the Laplace transform techniques solutions for the linear coupled differential equations are obtained in a closed form. It is observed that the temperature distribution (and hence the heat transfer at the wall) is unaffected by the free convection currents. Only the velocity and the shear stress vary with free convection currents.