航空模型燃料与氢气掺混微尺度燃烧数值模拟  

Numerical simulation of micro-scale combustion characteristics of jet fuel surrogate/hydrogen mixtures

作　　者：陈星赫 苏晟 王娟 CHEN Xinghe;SU Sheng;WANG Juan(School of Energy and Power Engineering,Beihang University,Beijing 100191,China;National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics,Beihang University,Beijing 100191,China)

机构地区：[1]北京航空航天大学能源与动力工程学院,北京100191 [2]北京航空航天大学航空发动机气动热力国家级重点实验室,北京100191

出　　处：《航空动力学报》2024年第10期263-273,共11页Journal of Aerospace Power

基　　金：国家自然科学基金(U2032119)。

摘　　要：对二维三级后台阶微燃烧器中以3种碳氢化合物(69%C_(10)H_(22)、11%C_(9)H_(18)、20%C_(9)H_(12))混合的Jet A-1模型燃料与氢气的掺混在纯氧中的燃烧进行了数值模拟,分析了燃料掺氢比、进气流速对微燃烧器内燃烧特性的影响。结果表明,所有火焰均可以稳定在微燃烧器第一后台阶(距离微燃烧器入口3 mm处)之前。随着掺氢比增加,火焰位置逐渐前移,火焰长度缩短,且微燃烧器内部的高温区面积减少,最高温度降低,上游燃烧强度更高但下游更低,CO和CH_(4)质量分数减小,裂解反应的发生位置前移且裂解产物的质量分数降低。随着入口进气流速增加,燃烧反应的高温区扩大,火焰中心位置和火焰前沿向微燃烧器出口移动和拉伸,掺氢比对壁面温度的影响减小,微燃烧器中心线OH质量分数整体增加,CO_(2)质量分数减小,CH_(4)质量分数增加,且裂解反应的发生位置后移且产物质量分数增加。结果表明:低速下可以掺混少量氢气得到更高的壁温从而获取更多能量。低速可能影响燃烧区燃料燃烧时的化学反应,从而造成上游的OH生成量减小。掺氢比的增加以及流速的降低会使CO质量分数波动更加明显。CO_(2)的质量分数最高时的掺氢比为25%。在高掺氢比和低进气流速下,乙炔大部分是靠燃料直接裂解生成,只有少量是通过丙烯的二次裂解生成。The combustion of a Jet A-1 surrogate(69%C_(10)H_(22),11%C_(9)H_(18)and 20%C_(9)H_(12))and hydrogen in pure oxygen was simulated in a two-dimensional three-step back stage micro-scale combustor.The effects of hydrogen mixing ratio and inlet gas flow rate on the combustion characteristics in the combustor were analyzed.The results showed that all the flames can be stabilized before the first stage of the micro burner(3 mm away from the micro burner inlet).With the increase of hydrogen mixing ratio,the flame position gradually moved towards the micro burner inlet,the flame length was shortened,and the high-temperature area inside the micro burner reduced,the maximum temperature decreased,the upstream combustion intensity was higher but the downstream combustion intensity was lower,the mass fractions of CO and CH_(4)decreased,the fuel cracking occurred closer to the micro burner inlet and the mass fractions of the cracking products decreased.With the increase of inlet gas flow rate,the high temperature zone of combustion reaction expanded,the flame center position and flame front moved and stretched towards the micro burner outlet,the influence of hydrogen mixing ratio on the wall temperature decreased,the OH mass fraction along the micro burner centerline increased,the CO_(2)mass fraction decreased,the CH_(4)mass fraction increased,and the cracking reactions occurred closer to the micro burner outlet and the mass fractions of the products increased.These results indicated that at low inlet gas flow rate,mixing a small amount of hydrogen can obtain high wall temperature and high energy.Low inlet gas flow rate may affect the chemical reaction in the combustion zone and reduce the amount of OH generated upstream.The increase of hydrogen mixing ratio and the decrease of flow rate can cause more obvious fluctuation of CO mass fraction.The hydrogen mixing ratio was 25%when the CO_(2)mass fraction reached the highest amount.At high hydrogen mixing ratio and low inlet gas flow rate,acetylene was mostly generated by direct

关 键 词：微尺度燃烧 掺氢比 燃烧特性 火焰位置 裂解 

分 类 号：V219[航空宇航科学与技术—航空宇航推进理论与工程]