Acoustic intensity vector probes

Abstract

Modern acoustic intensity measurement techniques began in the early 1980's with the realization that the imaginary part of the cross-spectral density was directly related to the active intensity component along the axis between two closely-spaced pressure microphones. Since acoustic intensity is a vector quantity, it was obvious that one would like to measure all three orthogonal components and to graphically represent acoustic power flow through space. Needing an interesting topic for a Ph.D. thesis at Penn State (and a way of funding it ..., thank-you US Navy), the task of investigating and developing the estimation of the acoustic intensity vector field fortunately came my way. This talk will present some of the early interesting and fun things that came out of working on in-air acoustic vector sensors. It will conclude with some more recent developments that have direct connections to the early acoustic vector probes that were built, tested, and used at Penn State.