Diffracted Edge Wave Prediction of Finite, Rectangular Rigid Plates using the Physical Theory of Diffraction

In noise control engineering and architectural acoustics, efficient predictions of sound diffraction around objects are of critical significance. An advanced diffraction theory has recently been explored for potential applications in architectural acoustics [Xiang, N. and Rozynova, A. J. Acoust. Soc. Am., 141, pp. 3785 (2017)] for some canonical objects of infinite sizes and for finite-sized rectangular plates [Rozynova, A. and Xiang, N. J. Acoust. Soc. Am., 142, (to appear 2018)]. This paper will report on further solutions of diffraction problems on finite, rectangular rigid plates. For purpose of numerical efficiency, the physical theory of diffraction (PTD) is applied to approximate the solutions of a finite-sized, rigid rectangular plate. The application of the PTD allows sound diffraction contributions to be determined separately from two pairs of edges of the rigid plate, while ignoring the edge waves around the corner in far-field. This paper will use numerical implementations of the theoretical predictions to show the efficiency of the application of the PTD in finite-sized objects. The numerical results implemented will also be compared with some preliminary experimental results carried out using an acoustical goniometer.