H_2O/CO_2组分对氢和乙烯超声速燃烧室性能影响数值模拟

Numerical Investigation of Effects of H_2O/CO_2 Vitiation on Performance of Hydrogen and Ethylene Supersonic Combustors

文章采用数值计算方法,评估了H2O与CO2两种污染组分对氢、乙烯超声速燃烧室性能的影响。针对纯净空气和含H2O/CO2污染空气,在来流总温、总压、马赫数、氧气摩尔含量、燃料当量油气比相当的条件下对氢、乙烯超声速燃烧室分别进行了三维、二维燃烧流场数值模拟,其中氢气当量比为0.42,乙烯当量比为0.57。计算中考虑的H2O组分摩尔含量包括7.5%和17.5%,CO2组分摩尔含量为7.5%。最后,将数值计算结果与相应实验测量值进行了对比分析。研究结果表明:数值计算结果与实验测量值比较接近,反映的H2O、CO2污染组分影响趋势一致的,计算结果可以有效分辨出污染组分对燃烧室性能的影响;H2O、CO2污染组分的存在降低了燃烧总温升、燃烧效率,进而降低了燃烧室壁面压力,总体上造成燃烧室性能的下降。

Section 1 of the full paper explains the method of numerical investigation mentioned in the title.Its core consists of：（1） we perform the 3D simulation of the combustion flow field of hydrogen-fueled supersonic combustor and the 2D simulation of ethylene-fueled supersonic combustor under the conditions of clean airstream and H2O/CO2 vitiated airstream in terms of total temperature,total pressure,Mach number,21% oxygen content and equivalent ratio;the equivalent ratio of hydrogen is 0.42 and that of ethylene is 0.57;the H2O content for contaminated airstream is 7.5% and 17.5% by mole,and the CO2 content is 7.5% by mole.Section 2 compares the simulation results with the results of experiments performed by us,as shown in Figs.3,4 and 10;the investigation results show that：（1） the simulated wall-pressure agrees well with the experimental wall-pressure;（2） the simulation results effectively identify the effects of H2O/CO2vitiation on the performance of supersonic combustor;（3） the presence of H2O and CO2 contaminants lowers down the total temperature rise and combustion efficiency and raises the Mach number in the flow field of the combustor,thereby reducing the wall pressure of the combustor in comparison with clean airstream;（4） the overall performance of the combustor gets poorer due to H2O/CO2 contamination.