冲压发动机燃烧不稳定性数值研究

Numerical investigations on the combustion instability for a ramjet engine

关键词:  冲压喷气发动机  燃烧室  燃烧稳定性  数值仿真

Key words:  Ramjet engine  Combustion chamber  Combustion instability  Numerical simulation

摘要:

使用FLUENT CFD计算软件开展了号冲压发动机燃烧不稳定性问题的数值研究。采用Finite-Rate/Ed-dy-Dissipation燃烧模型,随机轨道颗粒模型,考虑燃油液滴的一次雾化、二次雾化、蒸发和掺混,计算获得燃烧室内部热释放率、压力随时间的变化曲线,依照瑞利准则讨论了该型号发动机燃烧不稳定性的机理。

Abstract:

In the present paper,numerical investigations on the combustion instability of a ramjet engine have been conducted using the Fluent CFD software. The Finite-Rate/Eddy-Dissipation model is selected. The stochastic tracking model which mimics the effects of turbulence on the liquid fuel droplet motion trajectory is adopt. The atomization,the evaporation and mixing of the liquid fuel droplet are simulated in the present calculation. The variations of the heat release rate and pressure in the combustion chamber with time are obtained. The mechanism of the combustion instability occurring in the ramjet engine is discussed.