Journal of Energy Engineering (에너지공학)

The Korean Society for Energy (한국에너지학회)
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Experimental Study of Flow Characteristics with Swirl Number on Dump Combustor

모형 가스터빈 연소기에서 스월수에 따른 유동 특성에 관한 실험적 연구

  • Park, Jae-Young (Graduate School of Mechanical Engineering, Pusan National University) ;
  • Han, Dong-Sik (Graduate School of Mechanical Engineering, Pusan National University) ;
  • Kim, Han-Seok (Korea Institute of Machinery & Materials) ;
  • Song, Ju-Hun (School of Mechanical Engineering, Pusan National University) ;
  • Chang, Young-June (School of Mechanical Engineering, Pusan National University) ;
  • Jeon, Chung-Hwan (School of Mechanical Engineering, Pusan National University)
  • Received : 2011.06.15
  • Accepted : 2011.11.18
  • Published : 2011.12.31
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Abstract

The swirl flow applied for high efficiency and reduction of emission such as NOx, CO in a gas turbine engine makes recirculation zone by shear layer in the combustion chamber. This recirculation zone influences a decreasing flame temperature and flame length by burned gas recirculation. Also it is able to suppress from instability in lean-premixed flame. In this study, it was found that the swirl flow field was characterized as function of swirl number using PIV measurement in dump combustor. As increasing swirl number, a change of flow field was presented and recirculation zone was shifted in the nozzle exit direction. Also turbulent intensity and turbulent length scale in combustor were decreased in combustion. It has shown reduction of eddies scale with swirl number increasing.

희박예혼합 가스터빈 연소기에 적용되는 스월 유동은 연소효율증가와 배기가스저감을 목적으로 적용된 것로 연소기 내 유동장의 전단층생성에 의한 재순환영역이 생성되게 한다. 이러한 재순환영역은 연소가스 재순환에 의한 화염온도와 화염길이를 낮추는 효과를 가지고 있다. 또한 희박연소에서 연소불안정성 억제효과도 있다. 본 연구에서는 모형가스터빈연소기에서 스월러를 이용하여 스월유동을 유도하고, 연소기 노즐에서 평균속도가 일정 할 때의 스월수 증가에 따른 유동장의 속도분포 특성을 분석하였으며 이때 PIV 계측 실험과 난류통계기법을 이용하여 난류인자들을 도출하였다. 스월수의 증가는 연소기 내부 유동장의 형태가 바뀌게 되고, 재순환영역의 위치가 연소기 노즐방향으로 이동하게 되어 화염길이를 줄여 주며, 난류강도와 난류길이 스케일이 감소하게 되어 에디의 크기가 작아짐을 확인하였다.

Keywords

References

  1. Gupta, A. K., Lilley, D. G. and Syred, N., 1984, "Swirl flows," Abacus Press, Turhbridge Wells, England.
  2. Coghe, A., Solero, G., and Scribano, G. Recirculation phenomena in a natural gas swirl combustor. Expl Thermal Fluid Sci., 2004, 28, 709-714. https://doi.org/10.1016/j.expthermflusci.2003.12.007
  3. Nejad, A. S. and Ahmed,S. A. Flow field characteristics of an axisymmetric udden-expansion pipe flow with different initial swirl distribution. Int. J. Heat Fluid Flow, 1992, 13(4), 314-321. https://doi.org/10.1016/0142-727X(92)90001-P
  4. Nejad, A. S. and Ahmed, S. A. Swirl affects on confined flows in axisymmetric geometries. J. Propuls. Power, 1992, 8(2), 339-345. https://doi.org/10.2514/3.23483
  5. Reddy, A. P., Sujith, R. I., and Chakravarthy, S. R. Swirler flow field characteristics in sudden expansion combustor geometry. J. Propuls. Power, 2006, 22(4), 800-808. https://doi.org/10.2514/1.15940
  6. Ahmed, S. A. Velocity measurements and turbulence statistics of a confined isothermal swirling flow. Expl Thermal Fluid Sci., 1998, 17, 256-264. https://doi.org/10.1016/S0894-1777(97)10039-5
  7. Brum, R. D. and Samuelsen, G. S. Two-component laser anemometry measurements of non-reacting and reacting complex flows in a swirl stabilized model combustor. Expl Fluids, 1987, 5, 95-102. https://doi.org/10.1007/BF00776179
  8. Sheen, H. J., Chen, W. J., and Jeng, S. Y. Recirculation zones of unconfined annular swirling jets. AIAA J., 1996, 34(3), 572-579. https://doi.org/10.2514/3.13106
  9. Sarpkaya, T. Vortex breakdown in swirling conical flows. AIAA J., 1971, 9(1), 1792-1799. https://doi.org/10.2514/3.49981
  10. So, R. M. C., Ahmed, S. A., and Mongia, H. C. Jet characteristics in confined swirling flow. Expl Fluids, 1985, 3, 221-230. https://doi.org/10.1007/BF00265105
  11. Turns, S. R., "An Introduction to Combustion : Concepts and Applications," 2nd Edition.