|在纯净空气与H2O/ CO2污染空气来流对比试验结果基础上,采用数值计算方法和化学动力学方法,研究了H2O和CO2污染组分对煤油燃料超声速燃烧的影响,获得了试验手段难以得到的燃烧室流场参数和性能数据。完成了相应的煤油燃料超声速燃烧室二维数值计算,其中匹配了进口总温、总压、马赫数、氧气摩尔分数和工作当量油气比。将数值计算结果与相应试验测量值进行了对比分析,并结合燃烧室流场数据、性能参数分析了H2O和CO2污染的动力学影响、以及对燃烧室性能的影响。研究表明:(1)数值计算结果与实验测量值总体上吻合,两种手段均体现了纯净空气来流时不同煤油当量油气比的燃烧室性能,并反映了一致的“污染效应”影响趋势；(2) H2O污染、H2O+ CO2污染的存在降低了煤油燃料超声速燃烧室性能,体现在燃烧诱导压升、燃烧效率、流向冲量增量的下降,而且随着污染组分含量的增加,燃烧室性能下降越加显著。
|关键词: 超声速燃烧 煤油燃料 污染效应 化学动力学 数值计算
|Numerical Investigation of H2O/CO2Vitiation Effects on Kerosene-Fueled Supersonic Combustion
LI Jian-ping, SONG Wen-yan, LUO Fei-teng, CHEN Liang
School of Power and Energy, Northwestern Polytechnical University, Xi’an 710072, China
|Based on the comparative experiment results, the effects of H2O and CO2contaminants on kerosene-fueled supersonic combustion were carefully investigated by numerical approaches and chemical kinetics analysis method, which can provide detailed insight into the vitiation effects on flow field and combustion chemistry that cannot be resolved by experimental instruments available. The two-dimensional reacting flow simulation of kerosene-fueled combustor flowpath was completed. During the present studies, the inflow total temperature, total pressure and oxygen mole fraction at combustor entrance were strictly matched between clean airstream and various vitiated airstream, and the working fuel equivalence ratio was also an important parameter to be strictly matched. The numerical results were compared with experimental data to validate the accuracy of the numerical modeling, and then the kinetics effects of H2O and CO2contaminants and the resulting combustion performance change were analyzed and discussed. The present efforts suggest that:(1) the numerical wall-pressure profiles agree well with the experimental measurement, both of which indicate the same combustor performance in clean air inflow and the same trend of vitiation effects in vitiated air inflow; (2) the presence of H2O or H2O+CO2contaminants results in combustor performance deterioration characterized by the decreases of combustion induced pressure-rise, combustion efficiency and streamwise impulse relative to those in clean air.
|Key words: Supersonic combustion Kerosene Vitiation effects Chemical kinetics Numerical simulation