A one-man portable sonic boom simulator

• Published in: Journal of sound and vibration 1975-05, Vol.40 (1), p.41-50
• Main Authors: Ellis, N.D., Rushwald, I.B., Ribner, H.S.
• Format: Article
• Language: English
• ISSN: 0022-460X; 1095-8568
• DOI: 10.1016/S0022-460X(75)80229-X

A portable sonic boom simulator has been developed for field tests on wildlife. Previous portable simulators have been mobile only by truck or trailer; the present device weighs 24·4 pounds including peripherals and is easily carried by one person. It consists of a shock tube charged by a compressed air bottle, coupled to an exponential horn. A low-pass acoustic filter is mounted in the horn; it serves to increase the ultra-short rise time of the shock waves (∼10 μs) to a value more nearly characteristic of sonic booms (∼0·5 ms). The simulated sonic booms mimic the loudness of typical sonic booms and have comparable overpressure and rise times. Calibration of the effective loudness is by subjective comparison with idealized standard sonic booms (N-waves). The calibration is carried out in the recently developed UTIAS loudspeaker driven sonic boom booth. The loud-speakers accurately reproduce the signatures to be compared which have been tape recorded, and they are judged against the N-waves for equal loudness by an observer in the booth. The outcome is expressed as equivalent sonic boom overpressure ( Δp) as a function of shock-tube driver pressure and observer position relative to the portable simulator.