Journal of the Korean Society of Propulsion Engineers (한국추진공학회지)

The Korean Society of Propulsion Engineers (한국추진공학회)
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A Study on the Turbopump Rotordynamic Characteristics due to Bearing Housing Structural Flexibility

베어링 하우징의 구조 유연성에 따른 터보펌프 회전체동역학 특성 연구

  • Received : 2013.06.05
  • Accepted : 2014.03.09
  • Published : 2014.04.01
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Abstract

A rotordynamic analysis is performed for a turbopump of 7 ton class liquid rocket engine considering bearing housing structural flexibility. Stiffness and damping characteristics of ball bearings and pump noncontact seals are reflected in a rotordynamic model. A dynamic model of bearing housing with lumped mass and stiffness is also applied to the rotordynamic analysis. Rotor critical speed and onset speed of instability are predicted from synchronous rotor mass unbalance response and complex eigenvalue analyses. The bearing housing structural flexibility effect on rotordynamic characteristics is investigated for both of bearing loaded and unloaded conditions respectively. From the numerical analysis, it is found that the effect of the housing structural flexibility significantly reduces the rotor critical speed and onset speed of instability.

베어링 하우징의 구조 유연성을 고려하여 7톤급 액체 로켓 엔진용 터보펌프의 회전체동역학 해석이 수행되었다. 볼 베어링과 펌프 비접촉 실의 강성 및 감쇠 특성이 회전체동역학 모델에 반영되었으며, 베어링 하우징의 동특성이 집중 질량 및 강성으로 모델링 되어 해석에 반영되었다. 동기 회전체 질량 불평형 응답 해석과 회전 속도에 따른 복소 고유치 해석으로부터 회전체의 임계속도와 불안정 운전 시작 속도를 예측하였다. 회전체동역학적 특성에 베어링 하우징이 미치는 영향이 베어링 부하 조건 및 무부하 조건에서 각각 검토되었다. 수치 해석 결과 베어링 하우징의 구조 유연성은 회전체의 임계속도와 불안정 운전 속도를 의미있게 감소시킬 수 있는 것으로 확인되었다.

Keywords

References

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