摘要
火焰面类模型最初是针对低速流动提出的湍流燃烧模型,本文针对其向超声速可压缩流动的推广研究进行了综述。对于火焰面模型,其数据库建立时环境压强为常数以及静焓与混合分数线性关系的假设在超声速流动中均不适用。数值实验发现:一方面,数据库中主要组分浓度对于环境压强的变化并不敏感,但中间产物浓度在不同压强下变化明显;另一方面,静焓与混合分数偏离线性关系这一因素所引起的火焰面模型获得的温度场差别很小。对于火焰面/进度变量模型,其数据库中进度变量的化学反应源项对于压强和静焓-混合分数关系的变化则很敏感,现有考虑这一影响的可压缩修正主要是通过针对利用未经修正的数据库PDF积分后的平均源项进行标度来实现。数值结果表明,可压缩标度方法可有效考虑高马赫数效应对进度变量源项的影响,从而改善火焰面/进度变量模型对超声速燃烧流动的模拟精度。
The flamelet model and flamelet/progress variable model are those turbulent combustion models originally established for low-speed flows.Studies on the extensions of the flamlelet models to supersonic compressible flows are reviewed.For the flamelet model,the assumptions of constant pressure and linear relation of static enthalpy and mixture fraction in the establishment of flamelet library are not suitable in supersonic flows.Numerical experiments reveal that:the main species concentrations in the flamelet library are not sensitive to the given pressure value,while the intermediate species concentration vary obviously with the change of the pressure;the deviation from the linear relation between static enthalpy and mixture fraction result in little influence on the obtained mean temperature field by the flamelet model.For the flamelet/progress variable model,the chemical source terms stored in the library are found very sensitive to the flow compressibility effects.The current compressibility corrections for this problem are designed based on a rescaling to the mean source terms after PDF integration using the library not considering compressibility effects.Numerical results indicate that the compressible rescaling method reasonably incorporates the influences of the high-Mach-number effects on the tabulated source term of the progress variable and effectively improves the simulation accuracy of the flamelet/progress variable model for supersonic combustion flows.
作者
高振勋
蒋崇文
李椿萱
GAO Zhenxun;JIANG Chongwen;LEE Chunhian(National Laboratory for Computational Fluid Dynamics,Beihang University,Beijing 100190,China)
出处
《空气动力学学报》
CSCD
北大核心
2020年第4期651-659,I0001,共10页
Acta Aerodynamica Sinica
基金
国家自然科学基金“面向发动机的湍流燃烧基础研究重大研究计划”面上项目(91641123)。
关键词
超声速燃烧
火焰面模型
火焰面/进度变量模型
可压缩修正
supersonic combustion
flamelet model
flamelet/progress variable model
compressibility correction
