James P. Cottingham
Shenobie Gresham
Joshua W. Mackenzie
Phys. Dept., Coe College, Cedar Rapids, IA 52402
Previous studies of a Helmholtz resonator excited by an air jet explored the dependence of the frequency and amplitude of the Helmholtz mode on jet speed. It was observed that there are domains of jet speed, separated by narrow transition regions, for which a single frequency Helmholtz mode occurs [R. Khosropour and P. Millet, J. Acoust. Soc. Am. 88, 1211--1221 (1990)]. In the current investigation, a series of measurements were made exploring the dependence of amplitude, frequency, and domain width on the jet angle as well as jet speed and jet width. In addition, the amplitude variations of the harmonics of the Helmholtz mode and the appearances of the first standing wave mode were studied, especially near transition regions.