Experimental Investigation of Cavitation in Flow around an Extended Wedge

Authors

1 semnan

2 sharif

Abstract

To establish a variety of cavitating flow regimes, the combined body with wedge nose and rectangular afterbody is usually used. In this research work, the nose angle and the afterbody dimensions of model were 60° and 22cmx10cmx1cm, respectively. Its fabricated material is nearly smooth steel with roughness of 0.01mm. Also, another model with 30° nose angle and the same dimensions of the afterbody is tested. Two mentioned bodies were installed at the test section of a high speed cavitation tunnel. If the speed and pressure of the flow in the tunnel are varied, first cavitation inception occurs, such as a white band at the interface. Then, a little decrease the cavitation number causes the sheet cavitation along the surfaces of the afterbody. However, they are not established simultaneously at the upper and lower planes of the afterbody. By increasing the length of the sheet cavitation, regular oscillation occurs. Observed cloud cavitation is due to the separation of sheet regime which occurs by the re-entrant jet. If cavitation number is decreased slowly, then the vapor sheet covers the upper and lower planes of the afterbody. At the same cavitation numbers, cloud cavitation regimes on the two mentioned planes are not equal. At an especial length of the sheet cavity, the rate of length increase will be intensified.

Keywords

References

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History

  • Receive Date: 19 March 2017
  • Revise Date: 19 February 2019
  • Accept Date: 19 September 2018
  • Publish Date: 22 June 2018

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