MECHANISMS FOR SOUND GENERATION IN INVISCID TWO-DIMENSIONAL VORTEX INTERACTIONS

Theoretical and numerical results obtained in the present investigation illustrate that the motions of the vorticity centroids and the unsteady deformation of the vortex cores are the sources of sound in the inviscid two-dimensional vortex interactions at low Mach number. A theory for the sound generation, based on the low Mach number vortex sound theory, is developed and the relationship between the core deformation and sound radiation for slightly deformed vortices is explicitly found. The unsteady vortex core deformation is also found to be important in all the interaction cases discussed.