Nearfield of an arbitrary piston in an infinite rigid baffle

Abstract

Numerical calculations of the nearfield of several types of under‐water radiators made in 1965 for NAA Columbus led to this author's rediscovery of the edge integral for pistons in an infinite rigid baffle. Interest in this very efficient numerical method applicable to any shape of plane piston was rekindled in conjunction with an ongoing investigation of the impedance of a plane symmetric axisymmetric stepped piston radiator (LL model 98 underwater loudspeaker). A program was devised for the TRS‐80 Mod III computer and Used to duplicate a recently published absolute pressure field map for the circular piston [New et al., J. Acoust. Soc. Am. 70, 1518–1526 (1981)]. The agreement between the maps will be discussed as well as the cost of computation to a specified accuracy. Real and imaginary components of pressure on the piston face will be given for several values of ka. The value of the edge integral method for understanding certain aspects of diffraction theory more fundamentally than is possible with th...