Journal of the Korean Society of Propulsion Engineers (한국추진공학회지)

The Korean Society of Propulsion Engineers (한국추진공학회)
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The Comparison of Spray Characteristics between FOOF and FOF Injectors used in Liquid Rockets

액체로켓용 FOOF와 FOF 인젝터의 분무특성 비교

  • 임병직 (서울대학교 기계항공공학부) ;
  • 정기훈 (서울대학교 기계항공공학부) ;
  • 윤영빈 (서울대학교 기계항공공학부)
  • Published : 2003.06.01
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Abstract

Triplet(FOF or OFO) injectors are commonly applied to liquid rockets which use LOX and hydrocarbon propellants. The FOF type injector has been known to have an advantage for the although to show lower combustion performance as compared by the OFO type. However, a large disparity between oxidizer and fuel orifice diameters of the FOF type injector may reduce both the combustion efficiency and stability so that as FOOF split triplet injector which splits a single oxidizer orifice into double orifices was designed. In the present study, spray characteristics of the FOOF injector were investigated and compared with those of the FOF injector undo. cold flow conditions. Mass distributions of oxidizer and fuel for both injectors were measured by using a PLLIF (Planar Liquid Laser Induced Fluorescence)technique, and each drop size was also measured by using an instantaneous photographic method. From the experimental results, we found out that FOOF shows more stable mixing efficiencies than the FOF. As for the drop size of both oxidizer and fuel, there was not a large difference between two injector types.

액체 산소와 탄화수소계 연료를 사용하는 로켓에서 삼중 충돌형(FOF, OFO) 인젝터가 흔히 사용된다. 일반적으로 FOF 형태가 OFO에 비해 낮은 성능을 보인다는 것이 알려져 있지만, 벽면 열전달에 있어서 보다 효율적인 방식이다. 한편, 산화제와 연료 분사구 직경 차가 큰 FOF 형태에서 산화제 분사구가 분리된 분리 삼중 충돌형 FOOF 인젝터(이하 FOOF 인젝터)가 제안된 바 있다. 본 연구에서는 비반응 분무 실험을 통해 FOOF 인젝터의 분무 특성을 FOF와 비교하였다. PLLIF 기법을 이용하여 산화제와 연료의 질량 분포를 측정하였고, 순간사진을 이용하여 액적의 크기를 측정하였다. 실험결과를 통해 FOOF 형태의 인젝터가 FOF에 비해 보다 안정적인 혼합 효율을 나타내며 액적 크기는 두 형태의 인젝터가 큰 차이 없이 비슷한 경향을 보임을 알 수 있었다.

Keywords

References

  1. D.T.Harrje et al, 'Liquid Propellant Rocket Combustion Instability', NASA SP-194, 1995
  2. J.PiePer et al, 'Performance and Stability Characterization of Liquid Oxygen/Kerosene Injectors at Aerojet', Liquid Propellant Rocket Combustion Instability, AIAA, 1995
  3. G.S.Gill and W.H.Nurick, 'Liquid Rocket Engine Injectors', NASA SP-8089, 1976
  4. A.Ferrenberg et al, 'Atomization and Mixing Study', NASA CR 178751, 1985
  5. AJ.Ravli, 'Design and Evaluation of High Performance Rocket Engine Injectors for Use with Hydncarbon Fuels', NASA TM 79319, 1979
  6. J.H.Rupe, 'A Gorrelation between the Dynamic Properties of a Pair of Impinging Streams and the Uniform of Mixture-Ratio Distribution in the Resulting Spray', JPL 20-209, 1956
  7. G.W.Elverum and T.F.Morey, 'Criteria for Optimum Mxture-Ratio Distribution Using Several Types of Impinging-Stream Injector Elements, JPL 30-5, 1959
  8. V.McDonell, V.Phi, and S.Samuelsen, 'Sturucture of Sprays Generated by Single Unlike Doublet Injectors', JPC 99-2464, 1999
  9. D.Talley et al, 'Accounting for Laser Sheet Extinction in Applying PLLJF to Sparys', JPC 96-0469, 1996
  10. V.McDonell and S.Samuelsen, 'Assessment of Liquid Fuel Distribution in Sprays using Planar Imaging Methods', Preceeding of the 1st Asia-Pacific Conference on Combustion 30-33, 1997
  11. W.E.Anderson et al, 'Impinging Jet Injector Atomization', Liquid Propellant Rocket Combustion Instability, AIAA, 1990
  12. L.Zajac, Correlation of Spray Drop Sze Distribution and Injector Variables' NASA 7-726, 1971
  13. R.McHale et al, 'Nonlinear Orifice Holes and Advanced Fabrication Techniques for Liquid Rocket Injectos', CR R 9271, 1974