A Chebyshev matrix method for the spatial modes of the Orr–Sommerfeld equation

Abstract
The Chebyshev matrix collocation method is applied to obtain the spatial modes of the Orr‐Sommerfeld equation for Poiseuille flow and the Blasius boundary layer. The problem is linearized by the companion matrix technique. For semi‐infinite domains a mapping transformation is used. The method can be easily adapted to problems with boundary conditions requiring different transformations.