Journal of the Korean Society of Propulsion Engineers (한국추진공학회지)

The Korean Society of Propulsion Engineers (한국추진공학회)
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High Frequency Signal Analysis of Oxidizer Pump for 7-tonf Turbopump

7톤급 터보펌프 산화제펌프의 고주파 신호 분석

  • Bae, Joon-Hwan (Turbopump Team, Korea Aerospace Research Institute) ;
  • Choi, Chang-Ho (Turbopump Team, Korea Aerospace Research Institute) ;
  • Choi, Jong-Soo (Department of Aerospace Engineering, Chungnam National University)
  • Received : 2020.07.22
  • Accepted : 2020.10.27
  • Published : 2020.12.31
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Abstract

7-tonf turbopump real-propellant tests in Naro Space Center were conducted and high-frequency signals from an accelerometer and pressure sensors installed on the casing and the inlet/outlet pipeline of LOX pump were analyzed to estimate the structural and hydrodynamic stabilities. Waterfalls, frequency spectrums and RMS(Root Mean Square) values of the measured signals were calculated and characteristic instability frequencies by the rotating cavitation and the rear floating ring seal(F.R.S) were investigated. Static pressures of the inlet/outlet pipeline and an acceleration of the pump casing are strongly affected on pressure fluctuation induced by the rear floating ring seal in the leakage path. Despite the acceleration RMS value seems totally small, the rotating-speed-related synchronous frequency affecting the shaft instability is distinctly observed in the frequency contour.

7톤급 터보펌프 실매질시험에서 계측된 고주파 신호인 가속도와 압력섭동에 대한 주파수 분석(waterfall, frequency spectrum), 실효값(RMS) 계산 등의 신호 처리를 통해 산화제펌프의 신뢰성을 평가하였다. 계측된 압력섭동 신호 분석을 통해 산화제펌프의 누설 유로에 위치한 산화제 후방 플로팅 링에 의한 강한 압력섭동이 발생하였고 이는 산화제펌프 입구 및 출구 압력과 가속도 신호에도 영향을 주는 것을 확인하였다. 터보펌프의 가속도 실효값 계산을 통해 정격 운용 조건에서의 터보펌프는 양호한 진동 성능을 보여주고 있으며 가속도 회전수 성분 중 축계에 영향을 주는 회전수 동기 주파수 성분이 강하게 나타나는 것을 확인하였다.

Keywords

References

  1. Kim, J.H., "Status of the Development of Turbopump in Korea," Journal of the Korean Society of Propulsion Engineers, Vol. 12, No. 5, pp. 73-78, 2008.
  2. Kim, J.H,, Hong, S.S., Jeong, E.H., Choi, C.H. and Jeon, S.M., "Development of a Turbopump for a 30 Ton Class Engine," AIAA Paper 2007-5516, 43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, Cincinnati, OH, July 2007.
  3. Hong, S.S., Kim, J.S., Kim, D.J. and Kim, J.H., "Performance Test of Turbopump Assembly for 75ton Liquid Rocket Engine Using Model Fluid," Journal of the Korean Society of Propulsion Engineers, Vol. 15, No. 2, pp. 56-61, 2011.
  4. Kim, J.S., Han, Y.M. and Ko, Y.S., "Construction and Validation Test of Turbopump Real-propellant Test Facility," Journal of the Korean Society of Propulsion Engineers, Vol. 19, No. 4, pp. 85-93, 2015. https://doi.org/10.6108/KSPE.2015.19.4.085
  5. Kwak, H.D., Kim, D.J., Kim, J.S., Kim, J.H., Noh, J.G., Park, P.J., Bae, J.H., Shin, J.H., Yoon, S.H., Lee, H.G., Jeon, S.M., Jeong, E.H., Choi, C.H., Hong, S.S., Kim, S.L., Kim, S.H. and Han, Y.M., "Performance Test of a 7 tonf Liquid Rocket Engine Turbopump", Journal of the Korean Society of Propulsion Engineers, Vol. 19, No. 2, pp. 65-72, 2015. https://doi.org/10.6108/KSPE.2015.19.2.065
  6. Jeong, E.H., Kwak, H.D., Kim, D.J., Kim, J.S., Noh, J.G., Park, M.J., Bae, J.H., Shin, J.H., Wang, S.W., Yoon, S.H., Lee, H.G., Jeon, S.M., Choi, C.H., Hong, S.S., Kim, S.L., Kim, S.H., Han, Y.M. and Kim, J.H., "Performance Test of a 75 tonf Rocket Engine Turbopump", Journal of the Korean Society of Propulsion Engineers, Vol. 20, No. 2, pp. 86-93, 2016. https://doi.org/10.6108/KSPE.2016.20.2.086
  7. Kim, D.J., Kang, B.Y., Choi, C.H. and Bae, J.H., "High Frequency Signal Analysis of LOx Pump for Liquid Rocket Engine under Cavitating Condition," Journal of the Korean Society of Propulsion Engineers, Vol. 22, No. 4, pp. 61-67, 2018. https://doi.org/10.6108/KSPE.2018.22.4.061
  8. Choi, C.H., Noh, J.G., Kim, D.J. Hong, S.S. and Kim, J.H., "Effects of floating-ring seal clearance on the performance of the pump," Journal of the Korean Society of Fluid Machinery, Vol. 10, No. 6, pp. 38-43, 2007. https://doi.org/10.5293/KFMA.2007.10.6.038
  9. Lee, Y.B., An, K.M., Kim, C.H. and Ha, T.W., "Comparison of Theoretical analysis with Test Results of Floating Ring Seals for the LRE Turbo Pump," Journal of the Korean Society of Fluid Machinery, Vol. 7, No. 6, pp. 21-27, 2004.
  10. An, K.M., Lee, Y.B., Kim, C.H. and Ha, T.W., "Experiment Study on the Leakage Performance Characteristics of Floating Ring Seal," Journal of the Korean Society of Tribologists and Lubricantion Engineers, Vol. 20, No. 4, pp. 183-189, 2004.
  11. Mariot, A., Arghir, M., Helies, P., and Dehouve, J., "Experimental Analysis of Floating Ring Annular Seals and Comparisons with Theoretical Predictions," ASME Journal of Engineering for Gas Turbines and Power, Vol. 138, No. 4, 042503, 2016. https://doi.org/10.1115/1.4031347
  12. Kim, D.J., Kang, B.Y. and Choi, C.H., "Operational Characteristic of Liquid Rocket Engine by Cavitation Instability at Low Inlet Pressure Condition," 2020 Korean Society of Propulsion Engineers Spring Conference, Korea, 2020-1015, Jul. 2020.
  13. Kang, D.H., "A Cause and Suppression Methods of Cavitation Instabilities in an Inducer for Rocket Engines," Ph.D. Thesis, Osaka University, 2010.