대한기계학회논문집B (Transactions of the Korean Society of Mechanical Engineers B)

  • 제39권9호
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  • Pages.751-759
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  • 2015
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  • 1226-4881(pISSN)
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  • 2288-5324(eISSN)
대한기계학회 (The Korean Society of Mechanical Engineers)
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정면에 정삼각주를 가진 원주의 유동장 특성실험

Flowfield Experiments for a Circular Cylinder Having a Front Triangular Prism

  • 노기덕 (경상대학교 기계시스템공학과.해양산업연구소) ;
  • 한상윤 (경상대학교 기계시스템공학과) ;
  • 주형관 (경상대학교 기계시스템공학과) ;
  • 강좌운 (경상대학교 기계시스템공학과) ;
  • 배태범 (경상대학교 기계시스템공학과) ;
  • 노우균 (경상대학교 기계시스템공학과)
  • Ro, Ki Deok (Dept. of Mechanical System Engineering.Institute of Marine Engineering, Gyeongsang Nat'l Univ.) ;
  • Han, Sang Yun (Dept. of Mechanical System Engineering, Gyeongsang Nat'l Univ.) ;
  • Ju, Hyung Gwan (Dept. of Mechanical System Engineering, Gyeongsang Nat'l Univ.) ;
  • Kang, Ja Un (Dept. of Mechanical System Engineering, Gyeongsang Nat'l Univ.) ;
  • Bae, Tae Beom (Dept. of Mechanical System Engineering, Gyeongsang Nat'l Univ.) ;
  • Noh, Woo Kyun (Dept. of Mechanical System Engineering, Gyeongsang Nat'l Univ.)
  • 투고 : 2015.05.20
  • 심사 : 2015.07.11
  • 발행 : 2015.09.01
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초록

본 연구는 상류측에 작은 정삼각주를 가진 원주의 유동장 특성을 양 항력측정 실험과 PIV를 이용한 가시화 실험으로 파악한 것이다. 실험 파라메터는 원주의 직경에 대한 정삼각주의 폭비(H/B=0.2~0.6) 및 원주의 전면에서부터 정삼각주까지의 거리 (G/B=0~3) 로 했다. 정삼각주의 폭비를 고정시킨 경우 원주의 항력감소율은 간격비가 증가할수록 증가하다 감소하는 특성을 보였다. 또한 같은 간격비에서는 정삼각주의 폭비가 클수록 원주의 항력감소율이 컸다. 원주의 Strouhal 수는 간격비가 증가할수록 증가하다 감소하는 특성을 보였다. 정삼각주을 설치한 경우 원주 상류측과 하류측에 정체영역이 나타났으며, 그 크기는 상류측은 삼각주의 폭비가 클수록 증가하는데 비해, 하류측은 거의 일정했다.

In this study, we investigate the Characteristics of the flowfields of a circular cylinder having a small triangular prism at the upstream side. We measure the fluid force on the circular cylinder and obtain a visualization of the flow fields using particle image velocimetry (PIV). The experimental parameters employed were the width ratios (H/B = 0.2~0.6) of the triangular prisms to the circular cylinder's diameter, and the gap ratios (G/B = 0~3) between the circular cylinder and the triangular prism. We observed that the drag reduction rate and Strouhal number of the circular cylinder increased and then decreased with G/B in the case of the same H/B. The drag reduction rate increased with H/B in the case of the same G/B. In the case where the circular cylinder had a small triangular prism, the stagnation regions were represented in the upstream and downstream sides of the circular cylinder.

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참고문헌

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