Journal of the Korean Society for Aeronautical & Space Sciences (한국항공우주학회지)

The Korean Society for Aeronautical and Space Sciences (한국항공우주학회)
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A Numerical Investigation of the Main Rotor Tip-vortex and Counter-rotating Vortex during Hovering Flight

주로터 제자리 비행 시 익단 와류와 Counter-rotating Vortex의 수치적 관찰

  • Jun, Jonghyuk (Division of Aerospace Engineering, Korea Advanced Institute of Science and Technology(KAIST)) ;
  • Chung, In Jae (Agency for Defense Development(ADD)) ;
  • Lee, Duck Joo (Division of Aerospace Engineering, Korea Advanced Institute of Science and Technology(KAIST))
  • Received : 2013.03.07
  • Accepted : 2013.09.30
  • Published : 2013.10.01
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Abstract

Effects of helicopter wakes on helicopter aerodynamics are serious, but the wake configuration is very complicated and hard to predict. The purpose of this study is the detailed observation of wake using numerical methods. Vortex lattice method and freewake method are used to track the vortices in the wake. In this paper, the wake configuration is observed during hovering flight. In the case of hovering flight at the moderate thrust level, besides tip vortex, counter-rotating vortex can be observed at the inboard part of blade. When the vortices move downward, tip vortex and counter-rotating vortex get close and influence to each other. Therefore, vortices are highly distorted due to their own instability.

헬리콥터의 후류가 공기력에 미치는 영향은 매우 크다. 하지만 후류의 형상은 매우 복잡하며 예상하기 힘들다. 본 연구에서는 수치적인 방법을 통하여 후류를 자세히 관찰할 것이다. 후류에서의 와류를 자세히 관찰하기 위한 수치적 방법으로는 와류격자법과 자유후류법을 사용하였다. 본 연구에서 제자리 비행에서의 후류 형상을 관찰하였다. 적절한 추력계수를 갖는 제자리 비행에서는 익단 와류 뿐 아니라 블레이드의 안쪽에서 발생하는 counter-rotating vortex도 관찰할 수 있다. 이러한 와류들이 아래로 내려가면서 익단 와류와 counter-rotating vortex가 서로 가까워지며 서로에게 영향을 끼치게 된다. 이에 따라 와류들은 자체적인 불안정성으로 인해 형상이 변한다.

Keywords

References

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