Classroom exercise programs for numerically predicting and graphically displaying propagation characteristics of sound

Abstract

Several computer programs will be described which were developed for an introductory graduate course in underwater acoustics that was offered at a government laboratory (DTNSRDC) where Tektronix or H.P. graphics computers were available to most of the students. One program numerically solves the acoustic field equations in one dimension by a finite difference method. This program has been used to illustrate the reflection of sound at boundaries and effects of transmission into a second (or third) medium where the acoustic impedance and sound speed might differ. A second program numerically solves the acoustic field equations in two spatial dimensions. A ray tracing program will be described which illustrates the major features of sound propagation in inhomogeneous media and a program which plots beam patterns for an array with an arbitrary number of elements spaced at arbitrary distances apart will also be presented. The programs are written in BASIC and include interactive features which allow the studen...