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

The Korean Society of Mechanical Engineers (대한기계학회)
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Change of Vortex Dynamics in the Cylinder Wake by the Lock-on to Oscillatory Incident Flow

진동 유동장에서 유동공진에 의한 실린더 후류의 와류 특성 변화

  • 김원태 (서울대학교 대학원 기계항공공학부) ;
  • 성재용 (순천대학교 기계자동차공학부) ;
  • 유정열 (서울대학교 기계항공공학부)
  • Published : 2003.11.01
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Abstract

When vortex shedding is locked-on to a single frequency oscillatory flow, the variations of vortex dynamics are investigated using a time-resolved PIV system. Wake regions of recirculation and vortex formation, dynamic behavior of the shed vortices and the Reynolds stress fields are measured in the wake-transition regime at the Reynolds number 360. In the lock-on state, reduction of the wake region occurs and flow energy distributed downstream moves upstream being concentrated near the cylinder base. To observe the dynamic behavior of the shed vortices, the trajectory of the vortex center extended to the inside of the wake bubble is considered, which describes well the formation and evolution processes. The Reynolds stresses and their contributions to overall force balance on the wake bubble manifest the increase of the drag force by the lock-on.

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References

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