Experimental visualization of acoustic resonances within a stadium-shaped cavity

Abstract

Acoustic resonances of an insonified water-filled stadium-shaped cavity are located and visualized in a noninvasive manner using a schlieren technique. The chaotic nature of the geometry is seen to affect the form of the resonance patterns observed. Individual eigenstates of the cavity can be resolved at low frequencies; in particular, the ``bouncing ball'' modes. In the high frequency (overlapping resonance) regime, nodal patterns are characterized by a network of ridges similar in form to those formed by a random superposition of plane waves. \textcopyright{} 1996 The American Physical Society.