Experimental Validation of a New Intensity Estimation Method

A new method of estimating acoustic intensity has recently been developed in an effort to improve the acoustical measurements of launch vehicles. This new method, known as the phase and amplitude gradient estimation (PAGE) method, improves upon the traditional finite difference p-p method of estimating acoustic intensity. The advantages and limitations of the PAGE method are investigated experimentally using measurements of loud speaker arrays. The measured data is compared qualitatively to the acoustic intensity field determined by modeling the loudspeakers as baffled circular pistons using an extension of the Rayleigh integral. The primary advantage of the PAGE method is that it allows for accurate intensity measurements over a larger frequency band. When measuring smoothly varying broadband sources, it is possible to unwrap the phase component of the PAGE method, allowing for accurate intensity estimates well above previous limitations. [Work supported by NASA.