Observed and Computed Waves of Aerodynamic Sound
Evidences are accumulating to show that the theory of vortex sound in the aeroacoustics can describe characteristic features of the waves radiated by a localized vortex motion at low Mach numbers. Examples are given for collisions of two vortex rings and interaction of a vortex ring with a cylinder. An unresolved problem in our study so far is whether there exists a monpolar (i.e. isotropic) component in the radiated waves which can be attributed to the viscous dissipation of kinetic energy. A discussion is given about implication of the octapole component observed in the experiment of oblique collision of two vortex rings.
KeywordsVortex Vorticity sinO Hongo
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