On Sound Diffraction Caused by Rigid Circular Plate, Square Plate and Semi-Infinite Screen

Abstract

Of the three problems named above, a theoretical solution due to Sommerfeld is known for the case of the semi-infinite screen when the wave front is plane and parallel to the edge of the screen. For the other two problems no theoretical solutions have been given. Both these cases are of interest in connection with the types of diffraction caused by a number of practical acoustic devices. Hence it was thought worthwhile to present some experimental data and to indicate a calculating procedure which, though not at all rigorous, accounts for a number of the observed facts. In the semi-infinite screen problem the theoretical solution is restated in forms suitable for numerical evaluation. Several graphs showing the sound pressure amplitudes in regions of particular interest are given.