Abstract: To investigate the mechanism of scalar transport, the methane fuel concentration and temperature transport and diffusion in ramjet dump combustor was simulated by large eddy simulation. The numerical results reveal the behavior of large eddy structures in the chamber and instantaneous distribution of fuel and temperature. Simulations show that large eddy structures dominate the diffusion of fuel and similarly affect intensively the transport of temperature. This provides a basis for the further design of ramjet dump combustor and for improvement of combustion status.

Key words: Ramjet engine;Dump combustion chamber;Fuel;Turbulent diffusion;Transport property;Numerical simulation

摘要： 为弄清突扩燃烧室内标量输运机理,采用大涡模拟方法数值模拟了几何结构简化的冲压发动机突扩燃烧室内湍流流动中燃料浓度以及温度等标量的扩散和输运过程。研究了大尺度涡结构随时间在空间的演化过程,给出了燃料浓度和温度场的瞬时空间分布。研究表明燃料的扩散特征直接决定于大涡结构,大涡结构也强烈的影响温度的输运过程。该研究结果为冲压发动机突扩燃烧室设计和改进燃烧状况提供了细观依据。

关键词: 冲压喷气发动机;突扩燃烧室;燃料;湍流扩散;输运性质;数值仿真