The stability of the unsteady flow of a Newtonian viscous medium, which is a superposition of two one-dimensional orthogonal shears in a layer between parallel planes, relative to the three-dimensional picture of kinematic perturbations, is investigated. Using the method of integral relations, sufficient integral estimates of the development of initial disturbances and their non-growth over an infinite time interval are derived. The cases of stationary main motion, acceleration and deceleration in different directions are considered.
D. V. Georgievskii (Wed,) studied this question.