Journal of the Korean Society of Propulsion Engineers (한국추진공학회지)

The Korean Society of Propulsion Engineers (한국추진공학회)
권호 표지
DOI QR코드

DOI QR Code

Effect of Fuel Equivalence Ratio on Scramjet-to-Ramjet Mode Transition

스크램-램제트 모드 천이에 미치는 연료 당량비의 영향

  • Ha, Jeong Ho (Department of Mechanical Engineering, Andong National University) ;
  • Yoon, Youngbin (Department of Mechanical and Aerospace Engineering, Seoul National University) ;
  • Ladeinde, Foluso (Department of Mechanical Engineering, The State University of New York) ;
  • Kim, Tae Ho (Department of Mechanical Engineering, Andong National University) ;
  • Kim, Heuy Dong (Department of Mechanical Engineering, Andong National University)
  • Received : 2017.03.01
  • Accepted : 2017.08.10
  • Published : 2018.02.01
Download PDF
⟨ Previous Next ⟩

Abstract

The generation mechanism of NAR is not yet understood. In the present study, an in-depth analysis of the computational results previously obtained by the authors is conducted to investigate the flow mechanism responsible for NAR. A theoretical analysis has also been performed to understand the gas dynamic features during transition from scramjet to ramjet mode. It is known that there exists a critical value of the fuel equivalence ratio at which the flow states at the inlet of isolator remain unchanged. An increase in the equivalence ratio over the critical value leads to a sudden change in the static pressure and the Mach number at the inlet of the isolator, which is responsible for the generation of NAR.

최근 이중모드 램제트 엔진에서 모드 천이는 격리부 출구 마하수의 불연속적인 변화를 일으킨다고 보고된 바 있다. 이 현상을 격리부 입구와 출구에서의 유효 유동 단면적과 압력비에 따라 나타내었으며, 이는 Non-Allowable Region (NAR)으로 설명되었지만, NAR의 발생 기구에 대한 이해는 여전히 부족한 실정에 있다. 본 연구에서는 NAR의 발생 원인에 대한 유동 메커니즘을 조사하기 위해, 앞서 수행한 수치해석 결과들의 상세 연구가 수행되었으며, 스크램제트에서 램제트로의 모드 천이발생 동안 기체역학적 특성에 대한 이해를 돕기 위해 이론해석도 수행되었다. 격리부 입구에서 유동 상태량이 수용할 수 있는 당량비의 임계값이 정해져 있는데, 이 임계값을 초과하는 당량비의 증가는 격리부 입구에서의 정압뿐만 아니라 마하수의 급격한 변화를 발생시키게 되며, 이는 NAR의 발생 원인이 된다.

Keywords

References

  1. Le, D.B., Goyne, C.P., Krauss, R.H. and McDaniel, J.C., "Experimental Study of a Dual- Mode Scramjet Isolator," Journal of Propulsion and Power, Vol. 24, No. 5, pp. 1050-1057, 2008. https://doi.org/10.2514/1.32591
  2. Sullins, G.A., "Demonstration of Mode Transition in a Scramjet Combustor," Journal of Propulsion and Power, Vol. 9, No. 4, pp. 515-520, 1993. https://doi.org/10.2514/3.23653
  3. Ha, J.H., Das, R., Ladeinde, F., Kim, T.H. and Kim, H.D., "Numerical Study on Mode Transition in a Scramjet Engine," Journal of the Korean Society of Propulsion Engineers, Vol. 21, No. 6, pp. 21-31, 2017. https://doi.org/10.6108/KSPE.2017.21.6.021
  4. Micka, D.J. and Driscoll, J.F., "Dual-Mode Combustion of a Jet in Cross-Flow with Cavity Flameholder," 46th AIAA Aerospace Sciences Meeting and Exhibit, Reno, N.V., U.S.A., AIAA 2008-1062, Jan. 2008.
  5. Fotia, M.L., "Mechanics of Combustion Mode Transition in a Direct-Connect Ramjet-Scramjet Experiment," Journal of Propulsion and Power, Vol. 31, No. 1, pp. 69-78, 2015. https://doi.org/10.2514/1.B35171
  6. Yang, Q., Hu, J., Chang, J., Zong, Y. and Bao, W., "Experimental Study on Combustion Mode Transition Effects in a Strut-Based Scramjet Combustor," Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, Vol. 229, No. 4, pp. 764-771, 2015. https://doi.org/10.1177/0954410014539288
  7. Heiser, W.H. and Pratt, D.T., Hypersonic Airbreathing Propulsion, 5th ed., AIAA Education Series, Reston, V.A., U.S.A., Ch. 6., 1994.
  8. Shapiro, A.H., The Dynamics and Thermodynamics of Compressible Fluid Flow, 1st ed., The Ronald Press Company, New York, N.Y., U.S.A., pp. 219-260, 1953.
  9. Liepmann, H.W. and Roshko, A., Elements of Gasdynamics, 1st ed., Dover Publications, New York, N.Y., U.S.A., pp. 39-61, 1957.
  10. Oosthuizen, P.H. and Carscallen, W.E., Introduction to Compressible Fluid Flow, 2nd ed., CRC press, New York, N.Y., U.S.A., pp. 305-372, 2013.