Effects of Velocity Slip and Temperature Jump on the Boundary Layer Flow and Heat Transfer over a Wedge

Abstract

KnRe 3/2 . This result indicates that for near continuum rarefied large Reynolds number flows, the thermal creep effect can be neglected. The heat transfer over a wedge is affected by, among others, velocity slip and temperature jump. The relative importance of these two effects is also examined. It is found that the ratio of the temperature jump and the velocity slip, Γ, is a function of gas properties only and is independent of wedge angle β. It is further shown that Γ is inversely proportional to Pr, the Prandtl number. For near continuum rarefied flow, Ks < 0.1, the non-dimensional heat transfer to the wall can be expressed as qc(1 + ψKs). ψ is a constant. For small Γ, ψ is positive and for large Γ, ψ is negative. The quantitative value of ψ depends on both β and Γ. A numerical procedure and the solutions for Falkner-Skan flows, including both flat plate (Blasius) flow and stagnation point flow, subject to both velocity slip and temperature jump boundary conditions are presented. The results of this study show that due to the effect of velocity slip, both the boundary layer thickness and the wall shear are reduced in comparison to that of non-slip (continuum) solution and that due to the combined effect of velocity slip and temperature jump, the thermal boundary thickness is reduced. This conclusion applies for all wedge angles.