EFFECT OF COUPLING AND LINEAR TRANSFORMATION OF WAVES IN SHEAR FLOWS

A new linear mechanism of reciprocal transformation of waves and a cor responding energy transfer in shear flows is discovered. The effect is demonstrated on the simplest example - the two-dimensional waves in u nbounded, parallel hydromagnetic flow with uniform velocity shear. The phenomenon discovered is of importance for magnetohydrodynamics and f usion plasma devices and for various terrestrial and astrophysical she ar flows. Grasping the result became possible thanks to the nonmodal a nalyses of the perturbation evolution in the flow.