Journal of the Korean Society for Aeronautical & Space Sciences (한국항공우주학회지)

The Korean Society for Aeronautical and Space Sciences (한국항공우주학회)
권호 표지
DOI QR코드

DOI QR Code

A Study on Prediction of Acoustic Loads of Launch Vehicle Using NURBS Curve Modeling

넙스(NURBS) 곡선 모델링을 이용한 발사체 음향하중 예측에 대한 연구

  • Received : 2017.05.24
  • Accepted : 2017.12.18
  • Published : 2018.02.01
Download PDF
⟨ Previous Next ⟩

Abstract

The Intense acoustic wave generated by the jet flame at the lift-off causes the vehicle to vibrate in the form of acoustic loads. The DSM-II(Distributing Source Method-II), which is a representative empirical acoustic loads prediction method, is a method of distributing a noise source along a jet flame axis and has advantages in calculation cost and accuracy. However, due to the limitation of the distributing method, there is a limit to accurately reflect the various launch pad configurations. In this study, acoustic loads prediction method which can freely distribute noise sources is studied. by introducing NURBS(Non-Uniform Rational B-Spline) modeling into empirical prediction method. For the verification of the newly introduced analytical technique of the NURBS, the acoustic loads prediction for the Epsilon rocket's low-noise launch pad shape was performed and the results of the analysis were compared with the existing prediction methods and experimental results.

발사체 발사 시 제트화염에 의해 발생하는 강력한 음향파는 음향하중의 형태로 비행체를 가진한다. 대표적인 경험적 음향하중 예측기법인 DSM-II(Distributed Source Method-II)는 제트화염 축을 따라 소음원을 배치하는 방법으로 계산비용 및 정확성 측면에서 장점을 갖는다. 하지만 소음원 배치 방법의 한계로 인해 다양한 발사대 환경을 정확하게 반영하기에는 한계가 있다. 본 연구에서는 넙스(Non-Uniform Rational B-Spline, NURBS) 곡선 모델링을 경험적 예측기법에 도입하여 자유롭게 소음원을 배치할 수 있는 음향하중 예측기법에 대한 연구를 수행하였다. 넙스 기법이 새롭게 도입된 해석기법의 검증을 위하여 Epsilon 로켓의 곡선형 저소음 발사대 형상에 대한 음향하중 예측을 수행하였고 해석 결과를 기존의 예측방법 및 실험 결과와 비교하였다.

Keywords

References

  1. Lighthill, M. J., "On sound generated aerodynamically, part I, general theory," Proceedings of the Royal Society of London, Vol. 211, Mar. 1952, pp.564-587. https://doi.org/10.1098/rspa.1952.0060
  2. Lighthill, M. J., "On sound generated aerodynamically, part II, turbulence as a source of sound," Proceedings of the Royal Society of London, Vol. 222, Feb. 1954, pp.1-32. https://doi.org/10.1098/rspa.1954.0049
  3. West, J., and Strutzenberg, L. L., "Development of Modeling Capailities for Launch Pad Acoustics and Ignition Transient Environment Prediction," 18th AIAA/CEAS Aeroacoustics Conference, 2012.
  4. Tsutsumi, S., Nonomura, T., Fujii, K., Nakanishi, Y., Okamoto, K., Teramoto, S., "Analysis of Acoustic Wave from Supersonic Jets Impinging to an Inclined Flat Plate," Seventh International Conference on Computational Fluid Dynamics, 2012.
  5. Eldred, K., "Acoustic Loads Generated by the Propulsion System," NASA SP-8072, 1971.
  6. Plotkin, K. J., Sutherland, L. C., and Vu, B. T., "Lift-off acoustics prediction for the Ares I launch pad," 15th AIAA/ CEAS Aeroacoustics Conference, 2009.
  7. Varnier, J., "Experimental study and simulation of rocket engine freejet noise," AIAA Journal. Vol. 39, No. 10, Oct. 2001, pp.1851-1859. https://doi.org/10.2514/2.1199
  8. Haynes, J., and Kenny, R. J., "Modifications to the NASA SP-8072 distributed source method II for Ares I lift-off environment predictions," 15th AIAA/CEAS Aeroacoustics Conference, 2009.
  9. Tatsukawa, T., Nagata, Y., Yamamoto, M., Nonomura, T., Oyama, A., Fujii, K., "Aeroacoustic Multiobjective Design Exploration of Rocket Launch Site Design," Institute of Space and Astronautical Science & Japan Aerospace Exploration Agency, 2013.
  10. Sutherland, L. C., "Progress and Problems in Rocket Noise Prediction for Ground Facilities," 15th AIAA Aeroacoustics Conference, 1993.
  11. Peterson, J., "How to use Knot Vectors," Albert Technical Memo, 1990.
  12. Tsutsumi, S., Ishii, T., Ui, K., Tokudome, S., Wada, K., "Study on Acoustic Prediction and Reduction of Epsilon Launch Vehicle at Liftoff," Journal of Spacecraft and Rockets, Vol. 52, No. 2, Mar. 2015, pp.350-361. https://doi.org/10.2514/1.A33010