Simulation of jet-noise excitation in an acoustic progressive wave tube facility

Alexander Steinwolf, Robert G. White, Howard F. Wolfe
2001 Journal of the Acoustical Society of America  
Acoustic excitation produced by jet-engine effluxes was simulated in a progressive wave tube ͑APWT͒ facility with a computer-based control system. The APWT siren is driven by a signal generated numerically in a PC and then converted into analog form. Characteristics of the acoustic pressure measured by a microphone are analyzed in digital form and compared with those prescribed for simulation. Divergence is compensated by immediate modification of the driving signal and this action is repeated
more » ... n the form of iterative process until the test specification is attained. Typical power spectral density ͑PSD͒ shapes with maxima at low and high frequencies were simulated. A "tailoring" approach has been also achieved when a test specification was determined directly from field measurements for the particular aircraft under consideration. Since acoustic pressure signals of high level differ from the Gaussian random process model, particularly in terms of asymmetric probability density function, a method has been developed to make the driving signal also non-Gaussian by simulating skewness and kurtosis parameters of the APWT acoustic excitation simultaneously with PSD control. Experimental results with Gaussian and non-Gaussian characteristics obtained for various PSD specifications including sharp and narrow peaks are presented in the paper.
doi:10.1121/1.1344159 pmid:11303918 fatcat:rbwybpqxz5h3no6bnhl7i4s6oa