Acoustic radiation from line excited plates—Asymptotic series

Abstract

The theoretical analysis for predicting the acoustic radiation from an infinite fluid‐loaded, elastic plate excited by a line force is presented. The acoustic pressure radiated by this coupled plate‐fluid system is given in an integral representation. A uniformly asymptotic series solution, obtained by the use of the modified saddle point and subtraction of poles method, is valid in the farfield and the nearfield, and is especially accurate at the coincidence angle where the first‐order approximation by the saddle point method overpredicts the acoustic pressure. The uniformly asymptotic series solution also predicts a decaying but nonvanishing surface acoustic pressure while the approximate solution from the saddle point method vanishes at the grazing angle. The solution was also obtained by numerical integration along the steepest descent path. Results obtained from the numerical integration are compared with the uniformly asymptotic series solution and excellent agreement has been observed.