Effect of corrugated wall on the stability of plane channel flow

摘要

In order to clarify effects of distributed roughness on the instability of wall-bounded shear flows, the instability of laminar channel flow bounded by corrugated wall is investigated experimentally. The experiment is conducted at subcritical Reynolds numbers for the linear instability of plane Poiseuille flow. The non-dimensional wavenumber of the corrugated wall is 1.02 and the amplitude is 4% of the channel half height. It is shown that such a slight waveness of the wall surface reduces the critical Reynolds number down to about 4000.