Numerical Solutions of the Perturbation Equation for Linear Flow

Two-dimensional nondivergent perturbations of linear flow are considered. By means of a simple numerical treatment indications concerning the conditions of exponentilal instability are obtained. Numerical solutions are further used to represent the approximate development of initial perturbations up to a certain time. The correctness of this procedure is shown in the case of the Couette flow. Finally perturbations of a symmetrical harmonic velocity profile are considered in relation to the question about the instability in a barotropic atmosphere.