超声速支板燃烧室中氢气火焰的超大涡模拟  

Very-large eddy simulation of hydrogen flames in strut-based supersonic combustor

作　　者：延冲 朴英[1] YAN Chong;PIAO Ying(School of Aerospace Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学航天航空学院,北京100084

出　　处：《航空动力学报》2023年第9期2142-2152,共11页Journal of Aerospace Power

摘　　要：采用超大涡模拟(VLES)方法对德国宇航中心(DLR)支板燃烧室中的超声速火焰进行了数值模拟,并使用基于守恒变量的爆炸模态分析方法(CCEMA)对火焰的稳定机理进行了分析。研究中采用了基于k-ω切应力输运(SST)模型的VLES湍流模型,以及基于Ingenito超声速燃烧模型(ISCM)和部分搅拌反应器(PaSR)模型的混合湍流燃烧模型。数值模拟方法预测的时间平均温度和流向速度分布与实验数据的吻合度较高。离散方法方面,提出了一种改进的低耗散激波捕捉格式,拥有更好激波分辨能力。相比原始格式,改进的格式进一步提高了燃烧室支板下游点火区内湍流/火焰结构的模拟保真度。火焰诊断结果表明:在着火点前,组分扩散、化学反应和激波压缩效应都对爆炸模态(CEM)起到正面促进作用。另外热爆炸效应相比自由基爆炸更为剧烈,说明了DLR燃烧室内的火焰稳定模式为扩散和压缩效应协助点火模式。The very-large eddy simulation(VLES)method was used to simulate the supersonic flames in the strut-injection hydrogen combustor of Germany’s Aerospace Centre(DLR),and the flame stabilization mechanism was analyzed by the conservative representation of chemical explosive mode analysis(CCEMA)method.The VLES turbulent model based on the k-ωshear stress transport(SST)model and the hybrid turbulent combustion model based on the Ingenito supersonic combustion model(ISCM)along with the partially stirred reactor(PaSR)model were adopted in this study.The timeaveraged temperature and streamwise velocity profiles predicted by the numerical methods were in good agreement with the experiment.In terms of discretization method,a modified low dissipation shockcapturing scheme with better shock-capturing ability was proposed.Compared with the original scheme,the simulation fidelity of turbulence/flame structures in the ignition zone was further improved by the modified shock-capturing scheme.The flame diagnostic also showed that the component diffusion,chemical reaction and shock compression effects played positive roles in promoting the explosion mode before the flame onset location.In addition,the thermal explosion effect was more intensive than the radical explosion,indicating that the flame stability mode in the DLR combustor is a diffusion and compression effects assisted-ignition mode.

关 键 词：超大涡模拟方法 超声速燃烧 激波捕捉格式 化学爆炸模态分析 高保真度数值模拟 

分 类 号：V411.3[航空宇航科学与技术—航空宇航推进理论与工程]