타원형 고리와에 의한 음향 반사(II) : 두 타원형 고리와의 상호 관통

Abstract

A vorticity field of the elliptic 팩tex filament in the low Mach number flow is generated when the configuration of the cold jet exit is elliptic shape. The leap-frogging motion, as it is sometimes called, is the `mutual threading motion` is developed between two vortex rings, and affects the far field acoustic signals significantly. In this study, the far field acoustic signals is validated by comparisons with the analytic solution of circular vortex ring interaction. And after that, flow and far field acoustic calculations for two elliptic vortex rings are investigated numerically. Vortex motions and acoustic signals from two identical elliptic vortex rings, placed initially with selected separation distances, are calculated. The characteristics of the kinematic motions of two elliptic vortex rings is that t재 elliptic 패rtex rings hate different eigenfrequencies: the first from the axis switching phenomena of elliptic 패rtex ring and the second from the leap-froggingphenomenon. The acoustic signals are accompanied with these characteristics. Especially, strong acoustic signals are generated at thin instant of leaf-frogging motion.