Near-Slit Effects on the Flow and Heat Transfer from a Stretching Plate in a Porous Medium

Abstract

The flow and heat transfer characteristics over a linearly stretching surface with suction or injection at the surface in a porous medium with internal heat generation or absorption are studied numerically for uniform surface temperature. The full governing equations are all considered for mapping out the solution near the slit and far away downstream from the extrusion slit. The effects of different parameters such as Darcy resistance (k ₁), Prandtl number (Pr), heat generation or absorption (Q), suction or injection (f _w ), and Reynolds number (Re) on the flow and heat transfer are studied. The results are presented in dimensionless forms of the skin friction coefficients and Nusselt numbers . Critical Reynolds numbers are obtained to distinguish between the self-similar and the nonsimilar regions using the various parameters mentioned earlier. The region very close to the slit is characterized by a large heat transfer rate to the porous medium, which increases with increasing absorption, Prandtl number, suction, and Darcy resistance. However, downstream, where the similarity solution is valid, both the heat transfer coefficient and the skin friction coefficient reach asymptotic values depending on the other parameters mentioned earlier and are Reynolds number-independent. Finally, results for the skin friction coefficient near the slit are also obtained with the critical Reynolds number to distinguish between the nonsimilar and similar regions.