EFFECTS OF CAVITATION ON PERIODIC WAKES BEHIND SYMMETRIC WEDGES,

Abstract

Measurements of the shedding frequency and spacing of cavitating vortex street wakes were made for four wedge models having apex angles of 15, 30, 60 and 90 degrees. The wake pattern made visible by the presence of cavitation bubbles enabled measurements of the shedding frequency and vortex street spacing to be taken. It was found that the cavitation produced negligible effects on the shedding frequency with decreasing cavitation number down to as low as half the incipient cavitation number. Further decrease in the cavitation number produced an increase in the shedding frequency to a maximum value followed by a decrease with a general decay to random shedding. The analysis of high speed motion pictures demonstrated a general decrease in the cross-stream spacing of the two rows of vortices with decreasing cavitation number. The longitudinal spacing of vortices in the same row also decreased with decreasing cavitation number followed by a rapid increase at cavitation numbers lower than that producing the peak frequency. (Author)

Document Details

Document Type
Technical Report
Publication Date
Feb 24, 1965
Accession Number
AD0612108

Entities

People

  • J. O. Young

Organizations

  • Pennsylvania State University

Tags

DTIC Thesaurus Topics

  • Cavitation
  • Frequency
  • Measurement
  • Motion Pictures

Fields of Study

  • Physics

Readers

  • Fluid Mechanics and Fluid Dynamics.
  • Marine Propulsion Engineering and Naval Architecture

Technology Areas

  • Space
  • Space - Hall-Effect Thruster