以美国Sandia实验室火焰D为研究对象,在采用κ-ε湍流模型、概率密度函数(PDF)法及详细化学反应机理模拟湍流燃烧的基础上,研究了辐射换热对湍流射流燃烧过程的影响。模拟中采用离散坐标法(DOM)求解辐射传递方程,并分别采用普朗克平均吸收系数和箱带模型计算燃烧气体的辐射特性参数。结果表明,考虑辐射换热的影响时,火焰温度及组分浓度分布计算值与实验值吻合更好,且采用考虑气体光谱辐射效应的箱带模型比仅随温度变化的普朗克平均吸收系数的计算值更接近实验值。因此,研究燃烧气体的辐射换热问题具有重要意义,同时需要考虑其光谱辐射效应。
Taken Sandia flame D as an example,the thermal radiation effects of turbulent jet flame was numerically investigated.Based on the turbulence and combustion modelling with realizableκ-εturbulence model,probability density function(PDF) model and detailed chemical mechanism, thermal radiative transfer equation(RTE) was solved by discrete ordinate method(DOM),and the radiative properties of combustion gases were calculated using Planck mean absorption and box model respectively.It shows that the estimated temperature and species concentration distribution of the flame agree well with the experimental data when the gas thermal radiation effect is considered. Furthermore,the result with box model which takes both the spectral effect and temperature into accounts is better than that of the Plank mean absorption coefficient method which is merely related with temperature.Therefore,thermal radiation effects of combustion gases are very important in the simulation of turbulent flame,and the spectral effects of combustion gases should be considered in detail.