DIFFRACTION OF PULSES BY OBSTACLES OF ARBITRARY SHAPE WITH A ROBIN BOUNDARY CONDITION. PART B. SEMI-FREE CASE.

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 integro-differential 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 space-time 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)

Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1966
Accession Number
AD0636532

Entities

People

  • Richard P. Shaw

Organizations

  • University at Buffalo

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Acoustic Waves
  • Agreements
  • Boundaries
  • Differential Equations
  • Diffraction
  • Equations
  • Integrals
  • Mathematics
  • Scattering
  • Stratified Fluids
  • Waves

Fields of Study

  • Mathematics

Readers

  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Fluid Dynamics.

Technology Areas

  • Space
  • Space - Hall-Effect Thruster