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PIV Measurements of Non-cavitating and Cavitating Flow in Wake of Two-dimensional Wedge-shaped Submerged Body

PIV를 이용한 2차원 쐐기형 몰수체 후류의 비공동 및 공동 유동장 계측

  • Hong, Ji-Woo (Department of Naval Architecture and Ocean Engineering, Chungnam National University) ;
  • Jeong, So-Won (Department of Naval Architecture and Ocean Engineering, Chungnam National University) ;
  • Ahn, Byong-Kwon (Department of Naval Architecture and Ocean Engineering, Chungnam National University)
  • 홍지우 (충남대학교 선박해양공학과) ;
  • 정소원 (충남대학교 선박해양공학과) ;
  • 안병권 (충남대학교 선박해양공학과)
  • Received : 2018.08.08
  • Accepted : 2018.12.13
  • Published : 2019.02.28

Abstract

The vortex flow behind a bluff body has been a subject of interest for a very long time because of its engineering applicability such as to vortex induced vibration. In the near wake of a bluff body, vortices are periodically shed in two shear layers, which originate in the trailing edges. The far wake is made up of the classical Karman vortices, which are connected together by streamwise and spanwise vortices. These vortex formations have been studied in many experimental and numerical ways. However, most of the studies considered non-cavitating flow. In this study, we investigated cavitating flow in the wake of a two-dimensional wedge. Experiments were conducted in a cavitation tunnel of Chungnam National University. Using a particle image velocimetry (PIV), we measured the velocity fields under two different flow conditions: non-cavitating and cavitating regimes. We also investigated the vortex shedding frequencies using an absolute pressure transducer mounted on the top of the test window. Throughout the experiments, it was found that the shedding frequency of the vortex was strongly affected by cavitation, and the Strouhal number could exceed its value in the non-cavitating regime.

Keywords

Particle image velocimetry;Wake flow;Cavitation;Vortex street

Acknowledgement

Supported by : 산업통상자원부

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