• Title/Summary/Keyword: 회전체 동역학

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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)

  • Jeon, Seong Min;Yoon, Suk-Hwan;Kim, Jinhan
    • Journal of the Korean Society of Propulsion Engineers
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    • v.18 no.2
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    • pp.35-41
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    • 2014
  • 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.

Rotor Dynamic Analysis of the High Speed Centrifugal Chiller (고속회전용 터보냉동기의 회전체 동역학 해석)

  • 이준근;박용석
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.4 no.3
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    • pp.193-198
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    • 2003
  • A rotor dynamic analysis is implemented to confirm the vibration stability of the high speed centrifugal chiller coupled with gear system. As the rotating speed of the centrifugal chiller under investigated is increased up to 17,605 rpm at the pinion rotating part, the bearing instability is getting higher and, furthermore, the rotor-bearing system might experience a few critical speed which lead to system failure due to the excessive vibration. In this study, considering the loading capacity and stability conditions, offset journal bearings are adopted for the pinion rotating system and general cylindrical bearing are used for motor part. From the modal analysis, the system is found to be stable as the synchronous rotating frequency does not come across with any whirl natural frequency and, in addition, the critical damping ratio which shows the damping characteristics of the system are positive over the all operating ranges. From these results the authors confirm the vibration stability of the rotor-bearing system suggested in this study.

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A study on the Modeling for Rotors Control with Dynamics Analysis S/W (동역학 S/W와 연계한 회전체 제어의 모델링에 관한 연구)

  • Lee W.C.;Kim S.W.;Kim J.S.;Park H.O.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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    • pp.906-909
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    • 2005
  • This study provides the method to build the rotor system model using dynamic analysis software. also, it introduces the traditional methods of the rotor system modeling and informs the each merits and demerits. We will make up the flexible system of rotor system model with ADAMS, multi-body dynamics S/W, in order to develop dynamics model and get the response of plant model near to real model through connection the SIMULINK of MATLAB. We will develop the computing dynamics-controling model possible controlled simulation similar to a real model with controlling the plant model.

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Rotordynamic Analysis of a High Thrust Liquid Rocket Engine Turbopump (고추력 액체 로켓 엔진용 터보펌프의 회전체동역학 해석)

  • Jeon, Seong-Min;Kwak, Hyun-Duck;Yoon, Suk-Hwan;Kim, Jin-Han
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.7
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    • pp.688-694
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    • 2008
  • A rotordynamic analysis is performed for a high thrust class liquid rocket engine turbopump considering the dynamic characteristics of ball bearings and pump noncontact seals. Complex eigenvalue problems are solved to predict the rotating natural frequencies and damping ratios as a function of rotating speeds. Synchronous rotor mass unbalance response and time transient response analyses are also performed to figure out the rotor critical speed and the onset speed of instability. From the numerical analysis, it is found that the rear bearing stiffness is most important parameter for the critical speed and instability because the 1st mode is turbine side shaft bending mode. The pump seal effect on the critical speed is enlarged as the rear bearing stiffness decreases and the front bearing stiffness increases.