Radiated sound energy of a fluid-loaded cylinder as a function of force time duration and multiple pulse time spacing.

Abstract

Transfer functions measured by near-field acoustical holography (NAH) are used to simulate the sound radiated by a point-driven, fluid-loaded cylindrical shell with spherical end caps in the time domain for a variety of force inputs [J. Acoust. Soc. Am. 90, 1656–1664 (1991)]. The accuracy of time and frequency domain processing is reviewed. Radiated sound energy as a function of the time duration of a single pulse driving force is studied. The results are partially explained by looking at the output sound power as a function of frequency. Radiated sound energy as a function of the time spacing between multiple pulses is also studied. Sound radiation from the entire shell, the ends, and the driver alone are used to explain results. Frequencies determined by modal analysis as structurally resonant, acoustically radiating, both resonant and radiating, and neither resonant nor radiating were simulated for both single and multiple pulse forces. Instantaneous acoustic intensity, instantaneous power, and the time integral of these quantities are analyzed. Conclusions on the importance of time-domain analysis are made.