ECHOES FROM HOLLOW ALUMINUM SPHERES IN WATER,

Abstract

Recorded far-field echoes from precision hollow aluminum spheres in water, with different shell thicknesses and with either water or air in the hollow interior, are compared with calculated echoes. Steady state echoes are investigated over a range of ka from 6 to 27, and individual pulsed echoes at ka = 20. Excellent verification is obtained for the features predicted by the theory. It is shown that the echoes are sensitive to changes in the elastic properties of the shell, particularly when the shell is thin. The experiments showed moreover that the echoes are dependent on the orientation of the sphere. This is due presumably to asymmetries in the structure and properties of the shell and emphasizes again the strong interrelation between sonar echoes and the nature of the material in the target. (Author)

Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1966
Accession Number
AD0634546

Entities

People

  • K. Jerome Diercks
  • Robert Hickling

Organizations

  • California Institute of Technology

Tags

DTIC Thesaurus Topics

  • Absorbers (Materials)
  • Advanced Materials
  • Aluminum
  • Asymmetry
  • Attitude (Inclination)
  • Elastic Properties
  • Engineered Materials
  • Far Field
  • Materials
  • Orientation (Direction)
  • Precision
  • Sonar Echoes
  • Steady State
  • Thickness
  • Verification

Readers

  • Acoustical Oceanography.
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering