Noise Source Identification in a Highly Reverberant Enclosure by Inverse Frequency Response Function Method: Numerical Feasibility Study

In highly reverberant enclosures, the identification of noise sources is a difficult and time consuming task. One effective approach is the Inverse Frequency Response Function (IFRF) method. This technique uses the inverse of an acoustic FRF matrix, that when multiplied by operating pressure response data reveals the noise source locations. Under highly reverberant conditions the deployment of a sound absorbing body is especially useful in reducing the effects of resonant modes that obscure important information in the FRFs. Without the absorption, the IFRF method becomes practically difficult to perform in these environments due to poor conditioning of the FRF matrix. This study investigates the feasibility of using Boundary Element and Finite Element Methods to establish the frequency response functions between selected panel points and microphones in the array. The advantage of numerical FRF development is a practical savings of time and physical effort by reducing the amount of data that must be acquired by experimental testing. By providing additional flexibility in the design of the test, the material selection for the absorptive center body, as well as the strategy of microphone deployment, could be made through use of numerical analyses without additional physical setup demands.