Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
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An Experimental Study on Startup Characteristics of a Center Body Diffuser for High Altitude Simulation

고공환경 모사용 Center Body Diffuser의 시동 특성에 관한 실험적 연구

  • Yeon, Hae In (Dept. of Aerospace Engineering, Chungnam Nat'l Univ.) ;
  • You, Isang (Dept. of Aerospace Engineering, Chungnam Nat'l Univ.) ;
  • Kim, Wan Chan (Dept. of Aerospace Engineering, Chungnam Nat'l Univ.) ;
  • Im, Ji Nyeong (Dept. of Aerospace Engineering, Chungnam Nat'l Univ.) ;
  • Ko, Young Sung (Dept. of Aerospace Engineering, Chungnam Nat'l Univ.)
  • 연해인 (충남대학교 항공우주공학과) ;
  • 유이상 (충남대학교 항공우주공학과) ;
  • 김완찬 (충남대학교 항공우주공학과) ;
  • 임지녕 (충남대학교 항공우주공학과) ;
  • 고영성 (충남대학교 항공우주공학과)
  • Received : 2015.09.08
  • Accepted : 2015.12.27
  • Published : 2016.02.01
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Abstract

An experimental study has been conducted to verify the startup characteristic of a Center Body Diffuser (CBD) for simulating a low pressure environment when at high altitudes. Vacuum chamber pressure and startup characteristics of the CBD were investigated according to various geometries of the center body structure by a cold gas flow test. The test results show that the startup pressure is lowest when the center body contraction angle is approximately $15^{\circ}$. The startup characteristic of the CBDs significantly improves when the diffuser inlet length ($L_d/D_d$) is decreasing and the divergence length ($L_s$) is increasing. Additionally, it is possible to simulate various high altitude, low pressure conditions for various rocket engines that have different nozzle expansion ratios by adjusting the center body's position inside the diffuser.

본 연구에서는 고고도의 저압 환경을 모사하기 위한 CBD(Center Body Diffuser)의 시동특성에 대한 실험적 연구를 수행하였다. Center Body Diffuser의 형상을 다양하게 구성할 수 있도록 실험 장치를 설계/제작하여, 상온 유동 실험을 통해 CBD 형상에 따른 저압환경 구현 성능과 시동 특성을 관찰하였다. 실험 결과 센터바디의 수축각이 약 15도 일 때 시동압력이 가장 낮은 것을 확인하였다. 또한 디퓨저 입구부 길이($L_d/D_d$)가 감소할수록, 확산부 길이($L_s$)가 증가할수록 시동특성이 크게 향상되었다. 또한 디퓨저 입구부 길이($L_d/D_d$) 변화만을 통해 진공 챔버 압력을 조절할 수 있는 CBD만의 설비적 장점을 확인하였다.

Keywords

References

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