Investigation of the combustion process in an ethylene-fueled scramjet combustor
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摘要: 在来流马赫数2.0的直连式燃烧设备上，研究了氢气引燃条件下带凹腔的超燃冲压发动机燃烧室内，从氢点火到氢与乙烯混合燃烧，再到乙烯单独燃烧的全过程的燃烧流动特性，通过纹影、火焰自发光、CH自发光以及OH-PLIF等手段瞬时同步研究了流场结构和火焰发展。先锋氢与乙烯的当量比分别约为0.33和0.10。整个燃烧过程分6个阶段，第一阶段为先锋氢注入之前的无反应流动，试验测定振荡频率约为400 Hz。第二阶段用于揭示先锋氢被点燃之前的流动特性，由于先锋氢的注入而产生的激波在下壁面反射并与凹腔内的激波相互作用，导致监测点压力增大。第三阶段描述了先锋氢的燃烧过程，从点火、火焰稳定直到壁面压力稳定，历时约26.0 ms。在0.1 ms内先锋氢点火对燃烧流场及流动结构产生重大影响，试验测量先锋氢燃烧产生的激波串的运动速度约为20 m/s，先锋氢稳焰模式为凹腔回流区稳定燃烧。第四阶段为氢气和乙烯混合燃烧，此阶段燃烧变得更加剧烈，激波串被推入隔离段内，以至于超出了观测范围，该阶段乙烯稳焰模式为剪切层稳定燃烧。第五阶段为乙烯的燃烧流动，当先锋氢停止喷注后，乙烯火焰在凹腔内的位置由上游向下游移动。最后一个阶段是乙烯单独燃烧直到火焰熄灭。初步分析表明，乙烯燃烧的CH自发光图片能定性研究其燃烧效率。Abstract: An experimental investigation was conducted in a direct-connect supersonic combustion facility simulating the inflow condition of Ma=2.0 to investigate the combustion process in an ethylene-fueled scramjet combustor with cavity and pilot hydrogen. The structure of the flow field and the flame development were visualized using the schlieren imaging, the flame luminosity imaging, the CH luminosity imaging and the planar laser-induced fluorescence (PLIF) of the OH radical. The equivalence ratios of pilot hydrogen and ethylene were about 0.33 and 0.10, respectively. The whole combustion process could be divided into six stages. In the first stage, there was a non-reaction cold flow before the hydrogen injection. And the frequency of oscillation was measured to be around 400 Hz, experimentally. In the second stage, the flow characteristics before the pilot hydrogen ignition were revealed, due to the hydrogen injection an oblique shock wave was generated, reflected on the bottom wall, and then interacted with the shock waves below the cavity, thus leading to the increase of the monitor pressure. The third stage was the hydrogen combustion, including ignition and flame stabilization. The process from the ignition of pilot hydrogen to the combustion stabilization lasted around 26.0 ms. In the first 0.1 ms, the ignition of pilot hydrogen had great effect on the flow field structures. The moving speed of the shock train caused by the combustion of pilot hydrogen was around 20 m/s. The stabilization mode of the pilot hydrogen flame was cavity recirculation stabilized combustion. The fourth stage was the intense combustion process of hydrogen and ethylene. The shock waves were pushed into the isolator, and thus exceeded the observation range. The ethylene flame stabilization mode was shear layer stabilized combustion. The combustion characteristics of ethylene were revealed in the fifth stage. When the pilot hydrogen was ceased, the ethylene flame moved from the cavity step to the cavity ramp. The last stage involved the combustion and flame blowout of pure ethylene. Preliminary analysis indicates that the CH luminosity images of ethylene combustion can be used to investigate combustion efficiency qualitatively.
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Key words:
- scramjet combustor /
- ethylene /
- ignition /
- flame stabilization /
- combustion charac-teristics
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图 1 中国空气动力研究与发展中心直连式脉冲燃烧风洞
Figure 1. Direct-connected pulse combustion wind tunnel of CARDC
图 2 超燃冲压发动机内流道型面及燃烧室示意图
Figure 2. Geometry of internal flow passage and the schematic diagram of a scramjet combustor
图 3 燃料(氢气、乙烯)、加热器和监测点压力随时间的变化
Figure 3. Pressure of fuel (hydrogen, ethylene), heater and monitor point variation over time
图 4 各阶段上壁面中心线时均沿程压力分布
Figure 4. The average pressure distribution on the centre line of the stages
图 5 第一阶段凹腔内的纹影图和计算流线图
Figure 5. The schlieren image and the streamline of cavity in the first stage
表 1 试验操作时序
Table 1. Experimental operation sequence
操作
时序流场
建立先锋氢
喷注火花塞
工作乙烯
喷注先锋氢
停止乙烯
停止t/ms －32.0 0 27.0 100.0 207.0 308.0 
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表 2 试验过程的描述
Table 2. Description of the test process
阶段 t/ms 描述 Part 1 －32.0~0 氢气未喷注前的无反应流 Part 2 0~27.0 氢气喷注但未点火的无反应流 Part 3 27.0~100.0 氢气单独燃烧 Part 4 100.0~207.0 氢气和乙烯共同燃烧 Part 5 207.0~308.0 乙烯单独燃烧 Part 6 308.0~398.0 燃烧熄灭过程
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[1] URZAY J. Supersonic combustion in air-breathing propulsion systems for hypersonic flight[J]. Annual Review of Fluid Mechanics, 2018, 50(1): 593-627. doi: 10.1146/annurev-fluid-122316-045217 [2] 田野, 乐嘉陵, 杨顺华, 等. 氢燃料超燃燃烧室流场结构和火焰传播规律试验研究[J]. 实验流体力学, 2019, 33(1): 72-78. doi: 10.11729/syltlx20180027TIAN Y, LE J L, YANG S H, et al. Experimental study on flow structure and flame development in a hydrogen-fueled supersonic combustor[J]. Journal of Experiments in Fluid Mechanics, 2019, 33(1): 72-78. doi: 10.11729/syltlx20180027 [3] 吴戈, 李韵, 万明罡, 等. 平面激光诱导荧光技术在超声速燃烧火焰结构可视化中的应用[J]. 实验流体力学, 2020, 34(3): 70-77. doi: 10.11729/syltlx20190168WU G, LI Y, WAN M G, et al. Visualization of flame structure in supersonic combustion by Planar Laser Induced Fluorescence technique[J]. Journal of Experiments in Fluid Mechanics, 2020, 34(3): 70-77. doi: 10.11729/syltlx20190168 [4] RUAN J L, DOMINGO P, RIBERT G. Analysis of combustion modes in a cavity based scramjet[J]. Combustion and Flame, 2020, 215: 238-251. doi: 10.1016/j.combustflame.2020.01.034 [5] GORDON R L, STÅRNER S H, MASRI A R, et al. Further characterisation of lifted hydrogen and methane flames issuing into a vitiated coflow[C]//Proc of the 5th Asia-Pacific Conference on Combustion. 2005. [6] GORDON R L, MASRI A R, MASTORAKOS E. Simu-ltaneous Rayleigh temperature, OH- and CH2O-LIF imaging of methane jets in a vitiated coflow[J]. Combustion and Flame, 2008, 155(1-2): 181-195. doi: 10.1016/j.combustflame.2008.07.001 [7] MASTORAKOS E. Ignition of turbulent non-premixed flames[J]. Progress in Energy and Combustion Science, 2009, 35(1): 57-97. doi: 10.1016/j.pecs.2008.07.002 [8] 张弯洲, 乐嘉陵, 杨顺华, 等. Ma4下超燃发动机乙烯点火及火焰传播过程试验研究[J]. 实验流体力学, 2016, 30(3): 40-46, 84. doi: 10.11729/syltlx20150161ZHANG W Z, LE J L, YANG S H, et al. Experimental research on ethylene ignition and flame propagation processes for scramjet at Ma4[J]. Journal of Experiments in Fluid Mechanics, 2016, 30(3): 40-46, 84. doi: 10.11729/syltlx20150161 [9] BRIESCHENK S, O'BYRNE S, KLEINE H. Laser-induced plasma ignition studies in a model scramjet engine[J]. Combustion and Flame, 2013, 160(1): 145-148. doi: 10.1016/j.combustflame.2012.08.011 [10] BRIESCHENK S, O'BYRNE S, KLEINE H. Ignition charac-teristics of laser-ionized fuel injected into a hypersonic crossflow[J]. Combustion and Flame, 2014, 161(4): 1015-1025. doi: 10.1016/j.combustflame.2013.09.024 [11] KUMARAN K, BABU V. Investigation of the effect of chemistry models on the numerical predictions of the supersonic combustion of hydrogen[J]. Combustion and Flame, 2009, 156(4): 826-841. doi: 10.1016/j.combustflame.2009.01.008 [12] NAKAYA S, TSUE M, KONO M, et al. Effects of thermally cracked component of n-dodecane on supersonic combustion behaviors in a scramjet model combustor[J]. Combustion and Flame, 2015, 162(10): 3847-3853. doi: 10.1016/j.combustflame.2015.07.021 [13] 何粲, 邢建文, 肖保国, 等. 矩形截面超燃发动机不同燃烧模态下的流场特征[J]. 实验流体力学, 2018, 32(4): 12-19. doi: 10.11729/syltlx20180022HE C, XING J W, XIAO B G, et al. Investigation on flow field characteristics of a rectangular scramjet in different combustion modes[J]. Journal of Experiments in Fluid Mechanics, 2018, 32(4): 12-19. doi: 10.11729/syltlx20180022 [14] QIN Q Y, AGARWAL R, ZHANG X B. A novel method for flame stabilization in a strut-based scramjet combustor[J]. Combustion and Flame, 2019, 210: 292-301. doi: 10.1016/j.combustflame.2019.08.038 [15] FÖRSTER F J, DRÖSKE N C, BVHLER M N, et al. Analysis of flame characteristics in a scramjet combustor with staged fuel injection using common path focusing schlieren and flame visualization[J]. Combustion and Flame, 2016, 168: 204-215. doi: 10.1016/j.combustflame.2016.03.010 [16] AN B, YANG L C, WANG Z G, et al. Characteristics of laser ignition and spark discharge ignition in a cavity-based supersonic combustor[J]. Combustion and Flame, 2020, 212: 177-188. doi: 10.1016/j.combustflame.2019.10.030 [17] TIAN Y, YANG S H, LE J L, et al. Investigation of combustion process of a kerosene fueled combustor with air throttling[J]. Combustion and Flame, 2017, 179: 74-85. doi: 10.1016/j.combustflame.2017.01.021 [18] TIAN Y, XIAO B G, ZHANG S P, et al. Experimental and computational study on combustion performance of a kerosene fueled dual-mode scramjet engine[J]. Aerospace Science and Technology, 2015, 46: 451-458. doi: 10.1016/j.ast.2015.09.002 [19] TIAN Y, YANG S H, LE J L. Numerical study on effect of air throttling on combustion mode formation and transition in a dual-mode scramjet combustor[J]. Aerospace Science and Technology, 2016, 52: 173-180. doi: 10.1016/j.ast.2016.02.027 [20] 钟富宇, 乐嘉陵, 韩亦宇, 等. 当量比对氢燃料超燃燃烧室流场结构和燃烧模态影响研究[J]. 推进技术, 2019, 40(2): 324-330. doi: 10.13675/j.cnki.tjjs.170776ZHONG F Y, LE J L, HAN Y Y, et al. Investigation for effects of equivalence ratio on flow structure and combustion mode in a hydrogen fueled scramjet combustor[J]. Journal of Propulsion Technology, 2019, 40(2): 324-330. doi: 10.13675/j.cnki.tjjs.170776 -
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