저선회 연소기에서 난류생성기 판 형상에 의한 연소특성 : Part I 비반응장 유동
Combustion Characteristics by Plate Shape of Turbulence Generator in Low Swirl Combustor : Part I Non-reactive Isothermal Flow
1
조회
0
다운로드
3
인용
0
참고문헌
키워드
초록
This paper investigates the concept of fractal grid as turbulence generator which has constant reduce rate of grid thickness in low swirl combustor. Turbulence performance comparison of with and without swirler in a non-reactive isothermal flow of model nozzle was investigated using a fractal grid with various RRBT ratios and a general grid with conventional perforated hole configuration. As comparison barometers of turbulence performance, turbulence mean velocity(), turbulence fluctuation(′) and turbulence intensity(′) were investigated. For all the case, the turbulence intensity of fractal grid was higher than the general grid based on perforated holes. A maximum ′ showed to locate at a minimum position of , which is consistent with wake interaction theory. Also, the turbulence intensity increased with smaller value of RRBT in fractal grid. With a constant bulk velocity of 6 m/s, the inner recirculation zone was not detected by using a PIV system and a hot-wire anemometry analysis with radial direction, which is a very important phenomenon to meet the low swirl combustion.
Abstract
This paper investigates the concept of fractal grid as turbulence generator which has constant reduce rate of grid thickness in low swirl combustor. Turbulence performance comparison of with and without swirler in a non-reactive isothermal flow of model nozzle was investigated using a fractal grid with various RRBT ratios and a general grid with conventional perforated hole configuration. As comparison barometers of turbulence performance, turbulence mean velocity(), turbulence fluctuation(′) and turbulence intensity(′) were investigated. For all the case, the turbulence intensity of fractal grid was higher than the general grid based on perforated holes. A maximum ′ showed to locate at a minimum position of , which is consistent with wake interaction theory. Also, the turbulence intensity increased with smaller value of RRBT in fractal grid. With a constant bulk velocity of 6 m/s, the inner recirculation zone was not detected by using a PIV system and a hot-wire anemometry analysis with radial direction, which is a very important phenomenon to meet the low swirl combustion.
참고문헌 (21)
- R. K. Cheng, "Scaling and Development of Low-Swirl Burners for Low-Emission Furnaces and Boilers", Proc. combust. Inst, 28, pp.1305~1313 (2000)
- Developmet of a Vane-Swirler for use in a Low NOx Weak-swirl Burner, "D.T. Yegian", AFRC, 1~20 (1996)
- Y. Deng, "Combustion and Exhaust Emission Charact eristics of Low Swirl Injector", Appl. Therm. Eng, 110, pp.170~180 (2017)
- M. R. Johnson, "A Comparison of the Flowfields and Emissions of High-swirl Injectors and Low-swirl Injectors for Lean Premixed Gas Turbines", Proc. Combust. Inst, 30(2), pp.2867~2874 (2005)
- 정황희, "An experimental study on the effect of a turbulence generating plate in low swirl combustor", Journal of Mechanical Science and Technology, 31(12), pp.6077~6084 (2017), 대한기계학회
- Derek Dunn-Rankin, "Lean Combustion Technology and Control", pp.161~178 (2016), Elsevier
- S. Laizet, "Low Mach Number Prediction of the Acoustic Signature of Fractal- Generated Turbulence", Int. J. Heat Fluid Flow, 35, pp.25~32 (2012)
- A. A. El-Azm Aly, "Experimental Study of the Pres sure Drop after Fractal-shaped Orifices in Turbulent Pipe Flow", Exp. Therm Fluid Sci., 34, pp.104~111 (2010)
- P. -A. Krogstad, "Freely Dec aying, Homogeneous Turbulence Generated by Multi-scale Grids", J. Fluid Mech, 680, pp.417~434 (2011)
- P.C. Valente, "Universal Dissipation Scaling for Nonequilibrium Turbulence", Phys. Rev. Lett., 108(21), pp.1~5 (2012)
- D. Hurst, "Scalings and Decay of Fractal-Generated Turbulence", Phys. Fluids, 19(3), pp.1~31 (2007)
- J. F. Ravoux, "An Embedding Method for Bluff Body Flows : Interaction of Two Side-by-Side Cylinder Wakes", Theor. Comput. Fluid Dynamics, 16, pp.433~466 (2003)
- 정황희, "저선회 모델 연소기의 연소특성 및 선회각도 영향", 한국추진공학회지, 20(4), pp.40~49 (2016), 한국추진공학회
- M. Han, "A Study on the Pattern s and Porosities of Turbulence Generator in Low-Swirl Combustor", The 55th KOSCO symposium, pp.167~169 (2017)
- A. A. Verbeek, "Fractal Turbulence Enhancing Low-Swirl Combustion", Combust. Flame, 162, pp.129~143 (2015)
- D. Littlejohn, "Fuel Effects on a Low-swirl Injector for Lean Premixed Gas Turbines", Pro. Combust. Inst., 31, pp.3155~3162 (2007)
- R.K. Cheng, "Laboratory Studies of the Flo w field Characteristics of Low-Swirl Inject ors for Adaptation to Fuel-Flexible Turbin es", J. Eng. Gas Turb. Power, 130, pp.1~10 (2008)
- M. Koyama, "Techincal A pplicability of Low-swirl Fuel Nozzle for Liquid-fueled Industrial Gas Turbine Comb ustor", Fuel, 107, pp.766~776 (2013)
- P.L. Therkelsen, "Parametric Study of Low-swirl Injector Geometry on its Operability", Proc. ASME, pp.1~10 (2012)
- M. Day, "A Combine d Computational and Experimental Charact erization of Lean Premixed Turbulent Low Swirl Laboratory Flame Ⅱ. Hydrogen Flames", Combust. Flame, 162, pp.2148~2165 (2015)
- G. E. Ballachey, "Prediction of Blowoff in a Fully Controllable Low-swirl Burner Burning Alternative Fuels: Effects of Burner Geometry, Swirl, and Fuel Composition", Proc. Combust. Inst., 34, pp.3193~3201 (2013)