Direct numerical simulation of channel flow with permeable walls

Abstract

A series of direct simulations of a fully-developed turbulent flow over a mesh-screen type permeable plate whose geometrical property is systematically changed is performed to identify the relationship between the wall pore structure and the flow characteristics in a wall-bounded turbulent flow. The flow resistance is found to be increased by increasing the porosity of the plate or by decreasing the pore size, and to be closely associated with the blowing/suction intensity through the pores. However, there exists a certain critical pore size, below which the flow resistance is decreased by decreasing the pore size, and the flow goes back to the classical impermeable channel ow. It physically means that, below the critical pore size, the pore is too small for fluid to go through it freely.