
Accession Number : AD0636532
Title : DIFFRACTION OF PULSES BY OBSTACLES OF ARBITRARY SHAPE WITH A ROBIN BOUNDARY CONDITION. PART B. SEMIFREE CASE.
Descriptive Note : Technical rept.
Corporate Author : STATE UNIV OF NEW YORK BUFFALO DIV OF INTERDISCIPLINARY STUDIES AND RESEARCH
Personal Author(s) : Shaw, Richard P.
Report Date : APR 1966
Pagination or Media Count : 43
Abstract : The velocity field resulting from the diffraction of a plane acoustic wave by a scattering obstacle of arbitrary shape with a Robin boundary condition, is found as the solution to an integrodifferential equation. Numerical values are found for the velocity on the surface of a long cylinder of square cross section struck longitudinally by a plane pulse through an approximation of the integral by finite summations over specified steps in space and time. Comparison with exact solutions available for certain regions of spacetime indicate good agreement. The solution for small values of K does not differ greatly from that for K = 0 indicating that the free boundary condition is a reasonable approximation for many physical problems. Values of K up to 1.0 (in appropriate nondimensional form) seem to give most reasonable rsults in terms of velocity; for K > 10 a formulation in terms of pressure seems more appropriate and for values 1 > K > 10 either form will do. (Author)
Descriptors : (*SOUND, *DIFFRACTION), (*BOUNDARY VALUE PROBLEMS, DIFFRACTION), INTEGRAL EQUATIONS, DIFFERENTIAL EQUATIONS, POTENTIAL THEORY
Subject Categories : Acoustics
Distribution Statement : APPROVED FOR PUBLIC RELEASE