Accession Number:

AD0686003

Title:

INADEQUACIES OF ACOUSTIC APPROXIMATIONS IN FLUID-SHELL INTERACTIONS,

Descriptive Note:

Corporate Author:

POLYTECHNIC INST OF BROOKLYN FARMINGDALE NY DEPT OF AEROSPACE ENGINEERING AND APPLIED MECHANICS

Personal Author(s):

Report Date:

1969-04-01

Pagination or Media Count:

37.0

Abstract:

Both results and discussions of investigations for the submerged circular cylindrical shell and the spherical shell were enumerated. They point to the limitations of the plane and cylindrical wave approximations, and clarify the reasons for these limitations. It should be noted that when non-radiating components of the shell-fluid response are significant, then the acoustic approximations inadequately predict the interaction phenomenon. Such components are significant when the motion of the structure induces closely-spaced when compared to the fluid wavelength adjacent compressed and rarified regions in the fluid. This is accompanied by an axial flow from the adjacent compressed and rarified regions. At high frequencies short fluid wavelengths this does not occur since sufficient time is not available. Thus, although the relative simplicity of the acoustic approximations make them attractive, one should be wary of using them when it is suspected that closely-spaced adjacent compressed and rarified regions are induced in the fluid. Author

Subject Categories:

  • Aerodynamics
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE