HYDRODYNAMIC PRESSURE MEASUREMENTS OF THE VERTICAL WATER ENTRY OF A SPHERE

Abstract

The phenomena associated with the vertical water entry of 2-inch- diameter aluminum spheres striking the water surface at 28 feet per second were investigated by the use of hydrophones placed below the water surface. The pressure recordings from the hydrophones were analyzed for the three distinct phases of the water-entry problem: namely, (1) impact phase, (2) cavity flow phase, and (3) cavity collapse. The impact phase was analyzed by means of a dipole theory and a momentum equation. The cavity flow phase was analyzed by the potential theory of a half-body placed in a uniform flow since the shape of the water-entry cavity is very similar to a half-body. A comparison of actual pressures recorded with those as predicted by the half-body theory show agreement within ten percent both outside and inside the cavity.

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Document Details

Document Type
Technical Report
Publication Date
Oct 26, 1966
Accession Number
AD0658323

Entities

People

  • V. C. D. Dawson
  • W. R. Hoover

Organizations

  • Naval Ordnance Laboratory

Tags

Communities of Interest

  • Weapons Technologies

DTIC Thesaurus Topics

  • Base Closures
  • Cameras
  • Dynamic Pressure
  • Energy
  • Equations
  • Flow
  • Geometry
  • Impact Point
  • Measurement
  • Measuring Instruments
  • New York
  • Ordnance Laboratories
  • Photographs
  • Pressure Distribution
  • Pressure Gages
  • Pressure Measurement
  • Resonant Frequency

Readers

  • Combustion and Flow Dynamics.
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • ballistics.