Prediction of Spin-Decay of Liquid-Filled Projectiles.

Abstract

An accurate method for predicting the spin-decay of liquid-filled projectiles throughout their flight is described. The method is based on Wedemeyer's model for the spin-up of the liquid payload. The in-bore spin-up process is predicted using numerical solutions of the Navier-Stokes equations and Wedemeyer's equation. Spin-decay calculations are compared to spin histories obtained from test firings of 155mm liquid-filled projectiles equipped with yawsondes. The 100%-filled cases show excellent agreement between the theory and the measurement throughout the entire flight; the errors being less than 0.8% of the measured spin rate. The errors are no larger than about 1% for 90%-filled cases. The theory is used to calculate the spin-up time of the liquid; defined as the time when 99% of the instantaneous rigid-body angular momentum is achieved. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1977
Accession Number
ADA043275

Entities

People

  • Clarence W. Kitchens Jr.
  • Nathan Gerber

Organizations

  • Ballistic Research Laboratory

Tags

Communities of Interest

  • Weapons Technologies

DTIC Thesaurus Topics

  • Aeronautics
  • Aircrafts
  • Angular Momentum
  • Boundary Layer
  • Differential Equations
  • Engineering
  • Equations
  • Free Flight
  • Jet Propulsion
  • Liquid Filled Projectiles
  • Materials Science
  • Measurement
  • Mechanical Engineering
  • Momentum
  • Navier Stokes Equations
  • Reynolds Number
  • Turbulent Mixing

Fields of Study

  • Physics

Readers

  • Control Systems Engineering.
  • Military History of the United States in the 20th Century.
  • ballistics.