Performance comparison of aero-ramp and transverse injector based on gas-pilot flame
doi: 10.13224/j.cnki.jasp.2014.02.021
Performance comparison of aero-ramp and transverse injector based on gas-pilot flame
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摘要: A direct performance comparison between the four-hole aero-ramp injector and single transverse injector in a dual-mode scramjet combustor was conducted. The mixing characteristics of two injectors were calculated by solving the three-dimensional (3-D) compressible Reynolds-averaged Navier-Stokes equations (RANS), with the help of the shear-stress-transport (SST) k-ω turbulence model. The numerical results show that the far field mixing efficiency of the aero-ramp injector is higher than that of the single transverse injector. High enthalpy vitiated air was heated to a total temperature of 1200K by hydrogen-oxygen combustion, entering the isolator entrance at a Mach number of 2.0. Non-reacting experimental conditions involved sonic injection of nitrogen to safely simulate ethylene injected into the combustor at a jet-to-free stream momentum flux ratio of 2.6. Schlieren photographs were obtained to analyze the shock structure around the injectors. Reacting test conditions involved sonic injection of ethylene at the jet-to-free stream momentum flux ratios ranging from 0.5 to 2.7. High speed camera was used to capture the flame structures in the near-field combustion. The experimental results show that the aero-ramp injector produce sustained combustion over a wider range of fuel-air ratios than the single transverse injector. At the identical jet-to-free stream momentum flux ratio, the aero-ramp has a larger isolator margin than the single transverse injector, demonstrating a better ability for avoiding overflows. However, the air specific impulse and total temperature recovery of two injectors, which are calculated by the one-dimensional (1-D) performance analysis code, are almost identical.Abstract: A direct performance comparison between the four-hole aero-ramp injector and single transverse injector in a dual-mode scramjet combustor was conducted. The mixing characteristics of two injectors were calculated by solving the three-dimensional (3-D) compressible Reynolds-averaged Navier-Stokes equations (RANS), with the help of the shear-stress-transport (SST) k-ω turbulence model. The numerical results show that the far field mixing efficiency of the aero-ramp injector is higher than that of the single transverse injector. High enthalpy vitiated air was heated to a total temperature of 1200K by hydrogen-oxygen combustion, entering the isolator entrance at a Mach number of 2.0. Non-reacting experimental conditions involved sonic injection of nitrogen to safely simulate ethylene injected into the combustor at a jet-to-free stream momentum flux ratio of 2.6. Schlieren photographs were obtained to analyze the shock structure around the injectors. Reacting test conditions involved sonic injection of ethylene at the jet-to-free stream momentum flux ratios ranging from 0.5 to 2.7. High speed camera was used to capture the flame structures in the near-field combustion. The experimental results show that the aero-ramp injector produce sustained combustion over a wider range of fuel-air ratios than the single transverse injector. At the identical jet-to-free stream momentum flux ratio, the aero-ramp has a larger isolator margin than the single transverse injector, demonstrating a better ability for avoiding overflows. However, the air specific impulse and total temperature recovery of two injectors, which are calculated by the one-dimensional (1-D) performance analysis code, are almost identical.
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[1] Ben-Yakar B, Hanson K.Cavity flame-holders for ignition and flame stabilization in scramjets:an overview[J].Journal of Propulsion and Power, 2001, 17(3):869-876. [2] Lin K C, Tam C J.Flame characteristics and fuel entrainment inside a cavity flame holder in a scramjet combustor[R].AIAA 2007-5381, 2007. [3] Gruber M R, Carter C D.Experimental studies of pylon-aided fuel injection into a supersonic crossflow[J].Journal of Propulsion and Power, 2008, 24(3):460-470. [4] Fuller R P, Wu P K.Comparison of physical and aerodynamic ramps as fuel injectors in supersonic flow[J].Journal of Propulsion and Power, 1998, 14(2):135-145. [5] Abbitt J D, Segal C, McDaniel J C, et al.Experimental supersonic hydrogen combustion employing staged injection behind a rearward-facing step[J].Journal of Propulsion and Power, 1993, 9(3):472-479. [6] Riggins D W, McClinton C R, Rogers R C, et al.Investigation of scramjet injection strategies for high mach number flows[J].Journal of Propulsion and Power, 1995, 11(3):409-418. [7] McMillin B K, Seitzman J M, Hanson R K.Comparison of NO and OH planar fluorescence temperature measurements in scramjet model flow[R].AIAA Journal, 1994, 32(10):1945-1952. [8] Cox S K, Fuller R P, Schetz J A.Vortical interactions generated by an injector array to enhance mixing in a supersonic flow[R].AIAA 94-0708, 1994. [9] Fuller R P, Wu P K, Nejad A S, et al.Fuel-vortex interactions for enhanced mixing in supersonic flow[R].AIAA 96-2661, 1996. [10] Eklund D R, Gruber M R.Study of a supersonic combustor employing an aerodynamic ramp pilot injector[R].AIAA 99-2249, 1999. [11] Anderson C D, Schetz J A.Liquid-fuel aeroramp injector for scramjets[J].Journal of Propulsion and Power, 2005, 21(2):371-374. [12] Olmstead D T, Gruber M R, Collatz M K.Cavity coupled aeroramp injector combustion study[R].AIAA 2009-5227, 2009. [13] Jacobsen L S, Gallimore S D, Schetz J A, et al.An improved aerodynamic ramp injector in supersonic flow[R].AIAA 2001-0518, 2001. [14] Maddalena L, Campioli T L, Schetz J A.Experimental and computational investigation of light-gas injectors in Mach 4.0 crossflow[J].Journal of Propulsion and Power, 2006, 22(5):1027-1037. [15] BonanosA M, Schetz J A, OBrien W F.Dual-mode combustion experiments with an integrated aeroramp-injector/plasma-torch igniter[J].Journal of Propulsion and Power, 2008, 24(2):267-273. [16] Jacobsen L S, Gallimorel S D, Schetz J A, et al.An integrated aeroramp injector/plasma-igniter for hydrocarbon fuels in a supersonic flow[R].AIAA 2001-1766, 2001. [17] YAN Minglei.Supersonic combustion experiments with an integrated aeroramp-injector/gas-portfire[D].Beijing:Beijing University of Aeronautics and Astronautics, 2011.(in Chinese) [18] Bonanos A M, Schetz J A, OBrien W F.Scramjet operability range studies of a multifuel integrated aeroramp injector/plasma igniter[R].AIAA 2005-3425, 2005. [19] Smith S, Scheid A, Eklund D, et al.Supersonic combustion research laboratory uncertainty analysis[R].AIAA-2008-5065, 2008. -
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