Stability and admittance of a channel flow over a permeable interface

Abstract

The stability and the admittance analysis are considered for a Poiseuille flow running over a permeable slab. The case where a suction, due to a cross flow, is present through both the channel and the porous slab is also dealt with. An analytic solution is found for the basic flow in the entire field whereas the stability analysis and the evaluation of the admittance at the interface are numerically carried out. The errors made in the usually simplified analyses are fully discussed