Finite-amplitude standing waves in a rigid-walled cavity.

Abstract

Finite-amplitude standing waves in air at ambient temperature contained in a rigid-walled rectangular cavity were experimentally investigated. The pressure waveform in the cavity was analyzed for harmonic content and compared to the theory of Coppens and Sanders as modified to include empirical losses. The waveforms for the nOO and OnO configurations were analyzed at strength parameters of about 0.5, 0.75, and 1.0, where the strength parameter is defined as MQ₁(y+1)/2. M is the Mach number of the fundamental, Q₁ is the quality factor of the fundamental resonance, and y is the ratio of specific heats. It is found that the theoretical model accurately predicts the shape and approximates the amplitudes of the harmonic components of the finite-amplitude standing waves.