Two Computer Programs for the Evaluation of the Acoustic Pressure Amplitude and Phase at the Bottom of a Wedge-Shaped, Fluid Layer Overlying a Fast, Fluid Half Space

摘要

The pressure amplitude and phase distribution along the interface between a tapered fluid layer and an underlying fast fluid bottom were investigated theoretically. Two computer models, both based on the method of images, were designed: WEDGE 1 assumes that the source is at a finite distance from the apex of the wedge, and WEDGE 2 assumes an infinite distance. The pressure amplitude along the interface rapidly falls off for distances closer to the apex than the distance at which adiabatic mode theory predicts cutoff for the lowest mode. This distance is termed the dump distance. The results of the two program agree whenever the source is several dump distances from the apex. The predictions of these programs will be used as input for a further program that will use the Green's function approach to predict the acoustic pressure field in the lower medium. (Author)