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

The Korean Society for Aeronautical and Space Sciences (한국항공우주학회)
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Effect of Injector Geometry on Cryogenic Jet Flow

극저온 제트 유동에 대한 분사기 형상의 영향

  • 조성호 (서울대학교 기계항공공학부) ;
  • 박구정 (서울대학교 기계항공공학부) ;
  • 길태옥 (서울대학교 기계항공공학부) ;
  • 윤영빈 (서울대학교 기계항공공학부, 항공우주신기술연구소)
  • Received : 2011.01.20
  • Accepted : 2011.03.28
  • Published : 2011.04.01
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Abstract

Characteristics of cryogenic single jet flow were investigated. Liquid nitrogen was injected into a high-pressure chamber and formed single jet. Ambient condition around jet was changed from subcritical to superctirical condition of nitrogen. Injector geometries also were changed. A shape of the jet and core diameter were measured by flow visualization technique, and core spreading angle was calculated. Flow instability was found at atmospheric pressure condition. As ambient pressure increased, core spreading angle was increased and maintained after certain pressure.

액체 질소를 이용하여 극저온 단일 제트 유동의 특성을 관찰하였다. 고압 챔버 내부에 액체 질소를 분사하여 단일 제트를 생성, 주위기체압력을 변화시킴으로써 아임계 조건부터 초임계 조건의 주위 환경에 따른 제트의 특성 변화를 확인하였다. 또한 분사기의 길이 대 직경비 및 분사기 내부 형상의 변화에 따른 제트의 특성 변화를 파악하였다. 유동 가시화를 통하여 극저온 제트의 형상 및 액주의 지름을 측정하였으며, 이로부터 액주의 확산각을 계산하여 이전 연구 결과와 비교하였다. 아임계 조건 및 초임계 조건에서의 제트의 형상 변화를 관찰하였으며, 주위기체압력이 대기압과 동일할 경우 제트 유동에서 불안정이 발생함을 확인하였다. 또한 주위기체압력이 증가함에 따라 액주의 확산각이 점차 증가하다가 일정 압력 이상에서 거의 일정하게 유지됨을 확인하였다.

Keywords

References

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