Incompressible turbulent flow in a permeable-walled duct

An analysis is made of fully developed turbulent flow in a parallel-plate channel having one porous bounding wall. A velocity slip model is employed to characterize the boundary condition at the porous surface. The turbulent transport processes in the. channel are represented via the Prandtl mixing length concept in conjunction with a modified form of the Van Driest damping factor. Numerical results are obtained for Reynolds numbers ranging from 5000 to 200,000 and for a wide range of values of a dimensionless slip grouping. The results show that velocity slip at the porous surface brings about a reduction in the friction factor, the extent of the reduction being accentuated with increasing Reynolds number. The velocity slip also causes a skewing of the velocity profiles, such that the location of the maximum velocity is shifted toward the porous wall.