Abstract: In order to study the effects of mixing fraction probability density function on the turbulent combustion，supersonic diffusion combustion was investigated based on steady flamelet model. Two turbulence flamelet databases obtained from ensemble averaging laminar flamelet database using [β]-PDF and [δ]-PDF，respectively，were compared. Furthermore，based on RANS/LES method，DLR(German Aerospace Center) hydrogen fueled scramjet combustor was intruduced to verify two different flamelet databases. It is found that intermediate component of the former database varies greater with variance of the mixture fraction. Compared with the [δ]-PDF，the fluctuating velocity of [β]-PDF is greater and it is in agreement with experimental results closely.

Key words: Supersonic diffusion combustion；PDF；Turbulence flamelet database

摘要： 为了研究混合分数概率密度函数对湍流扩散燃烧的影响，采用稳态火焰面模型描述超声速扩散燃烧过程，分别采用[β]-PDF和[δ]-PDF方法对层流火焰面数据库积分得到两种湍流火焰面数据库，并对比分析了湍流火焰面数据库。结合混合RANS/LES程序，利用DLR氢燃料超燃燃烧室算例进一步对比验证采用不同PDF方法生成的湍流火焰面数据库。研究结果表明，混合分数[β]分布数据库中间组分随混合分数方差变化大，采用混合分数[β]分布的算例计算结果脉动速度较大，与实验结果符合得更好。

关键词: 超声速扩散燃烧；概率密度函数；湍流火焰面数据库