RESONANCE INSTABILITY OF THE FLOWS WITH CLOSED STREAMLINES.

This paper deals with the three-dimensional instability of two-dimensional incompressible flows where the streamlines represent ellipses with small eccentricities. The presence of instability which we call 'resonance' or 'parametric' one, is shown both theoretically and experimentally. The predictions of the linear theory developed here are in good agreement with the experimental data. The present paper is a continuation of the cycle of works.