Vortices and waves in planar and disk flows

We present and analyse a linear, non-resonant phenomenon of wave generation by vortices in smooth shear flows. The phenomenon is closely related to non-normality of linear dynamics of perturbations in such flows and can be well interpreted by the use of the non-modal approach, i.e. by following in time the linear dynamics of spatial Fourier harmonics of the vortex mode perturbations. We will consider both a planar two-dimensional flow with linear velocity profile and a keplerian disk flow. We will also present numerical simulations in both configurations. These results may be important for the dynamics of accretion disks.