Asymptotic boundary conditions for the analysis of hydrodynamic stability of flows in regions with open boundaries

A new approach to formulation of asymptotic boundary conditions for eigenvalue problems arising in numerical analysis of hydrodynamic stability of such shear flows as boundary layers, separations, jets, wakes, characterized by almost constant velocity of the main flow outside the shear layer or layers is proposed and justified. This approach makes it possible to formulate and solve completely the temporal and spatial stability problems in the locally parallel formulation, reducing them to the ordinary algebraic eigenvalue problems.