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Flow Characteristics and Drag Reduction at Different Pressures of Counterflow Air Jets in Supersonic Flow

초음속 환경에서 역분사 공기 제트의 압력 변화에 따른 유동 특성 및 항력 감소

  • Choi, Jongin (Department of Aerospace Engineering, Graduate School of Chungnam National University) ;
  • Lee, Jaecheong (Department of Aerospace Engineering, Graduate School of Chungnam National University) ;
  • Kang, Seungwon (Department of Aerospace Engineering, Graduate School of Chungnam National University) ;
  • Huh, Hwanil (Department of Aerospace Engineering, Chungnam National University)
  • Received : 2017.11.16
  • Accepted : 2018.01.08
  • Published : 2018.02.01

Abstract

To improve the performance of high-speed vehicles, various studies have been carried out on the head of vehicles. In this study, tests are conducted on flow characteristics and drag reduction using counterflow air jets in supersonic flow. The flow is visualized by the Schlieren method using a high-speed camera, and the drag is measured using a torque sensor according to the injection pressure conditions. The results of the measurements indicate that the flow changes from unsteady state to steady state for injection pressure ratios between 1.58 and 1.70, and drag reduction is observed as the pressure of the counterflow air jets increases.

초고속 비행체의 성능을 향상시키기 위해 비행체 선두부에 대한 연구가 다양하게 수행되고 있다. 본 연구에서는 초음속 영역에서 역분사 공기 제트를 활용하여 유동 특성 및 항력 감소에 대한 실험 연구를 수행하였다. 고속카메라를 활용한 쉴리렌 가시화 방법으로 분사 유동을 가시화 하였으며, 토크센서를 이용해 분사 압력 조건에 따른 항력 변화를 측정하였다. 측정 결과, 분사 압력비 1.58 ~ 1.70 조건에서 비정상 상태의 유동이 정상 상태로 변화하였으며, 역분사 공기 제트의 분사 압력이 높을수록 항력이 감소하는 경향을 보였다.

Keywords

References

  1. Finley, P., "The Flow of a Jet from a Body opposing a Supersonic Free Stream," Journal of Fluid Mechanics, Vol. 26, Issue 2, pp. 337-368, 1966.
  2. Morimoto, N., Yamashita, J., Aso, S. and Tani, Y., "An Expedient for Alleviating Aerodynamic Heating and Drag on Capsule Forward Heat Shield," 53rd Aerospace Sciences Meeting, Kissimmee, Florida, U.S.A., AIAA 2015-2080, Jan. 2015.
  3. Shang, J.S., Hayes, J., Wurtzler, K. and Strang, W., "Jet-spike Bifurcation in High-speed Flows," AIAA Journal, Vol. 39, No. 6, pp. 1159-1165, 2001. https://doi.org/10.2514/2.1430
  4. Shang, J.S., "Plasma Injection for Hypersonic Blunt-body Drag Reduction," AIAA Journal, Vol. 40, No. 6, pp. 1178-1186, 2002. https://doi.org/10.2514/2.1769
  5. Kim, J.H., Kang, S.W., Lee, J.C. and Huh, H.I., "Key Parameters and Research Review on Counterflow Jet Study in USA for Drag Reduction of a High-speed Vehicle," Journal of The Korean Society for Aeronautical and Space Sciences, Vol. 44, No. 1, pp. 23-32, 2016. https://doi.org/10.5139/JKSAS.2016.44.1.23
  6. Kang, S.W., Choi, J.I., Lee, J.C. and Huh, H.I., "Preliminary Results on Plasma Counterflow Jets for Drag Reduction of a High Speed Vehicle," Journal of the Korean Society of Propulsion Engineers, Vol. 20, No. 6, pp. 101-112, 2016. https://doi.org/10.6108/KSPE.2016.20.6.101
  7. Choi, J.I., Kang, S.W., Lee, J.C. and Huh, H.I., "The Configuration and Fundamental Test of Plasma Counterflow Jet," Proceeding of The Korean Society for Aeronautical and Space Sciences Fall Conference, Jeju, Korea, pp. 1160-1161, Nov. 2016.
  8. Choi, J.I., Lee, J.C., Kang, S.W. and Huh, H.I., "Research Trends on Heating and Drag Reduction of High-Speed Vehicles Using Counter-Flow Jets in Japan," The KIMST Spring Conference, Jeju, Korea, pp. 1111-1112, Jun. 2017.
  9. Anderson, J.D. JR., Fundamental of Aerodynamics, 5th ed., Textbooks, Seoul, Korea, Ch. 8, 2011.