双侧切向进气固冲发动机二次燃烧仿真

Simulation of Secondary Combustion for Zygomorphic Tangential Air-in Solid Rocket Ramjet

研究发动机性能优化问题,燃烧是关键技术。为提高固冲发动机二次燃烧效率,提出了一种新型切向进气方式,采用Realizablek-ε湍流模型及单步涡团耗散燃烧模型,对双侧切向进气式固冲发动机补燃室内三维反应流场进行了数值仿真,研究了切向进气对固冲发动机二次燃烧的影响。当空气射流以切向进入补燃室时,气流产生旋转,燃料与空气的混合更充分,燃烧效率更高,并且有利于发动机壁面热防护。当气流切入角度增大时,补燃效率先升后降,对于具体发动机结构,存在一使燃烧效率最大的切入角,根据研究的模型发动机结构进行仿真,结果表明,提高了发动机性能,加快了燃烧的速度,对固冲发动机设计提供重要依据。

A new tangential air-in mode was presented to improve the secondary combustion efficiency of solid ducted rocket motor.The 3D reaction flow field in the afterburning chamber of solid ducted rocket motor with zygomorphic mode was numerically simulated by means of Realizablek-εturbulence model and onestep eddy-dissipation combustion mode1.The effects of swirl flow aroused by air injection cutting into combustion on secondary combustion were investigated.The results show that when air swirl injection enters into secondary chamber,blending rate and combustion are finished fully,furthermore,being good for the thermal protection of wall.When the tangential duct intake angle increasing,the secondary combustion efficiency increasd then fell,there is an angle value that makes secondary combustion efficiency impulse higest for a certain configuration of solid rocket ramjet.The motor we studied is about 15 degree.The conclusion is important for the design of solid ducted rocket motor.