旋转射流对含硼固体火箭冲压发动机二次燃烧的影响

Influence of the swirl injection for secondary combustion ofboron based ducted rocket

关键词:  固体火箭冲压发动机  旋转射流  硼  二次燃烧  数值仿真

Key words:  Ducted rocket  Swirljet  Boron  Secondary combustion  Numerical simulation

摘要:

为提高固体火箭冲压发动机二次燃烧效率,将旋转射流技术引入固体火箭冲压发动机设计,采用Realizable k-ε湍流模型、单步涡团耗散燃烧模型以及KING硼粒子点火和燃烧模型,利用Fluent软件开展了旋转进气和一次燃气旋转含硼固体火箭冲压发动机补燃室三维反应流场流数值分析。研究结果表明,当空气射流切向进入补燃室时,气流产生的旋转均使燃料与空气的混合更充分,燃烧效率更高。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,存在一个使燃烧效率最大的切入角,针对研究的模型发动机结构,此值在20°附近；当一次燃气旋流数的增加,二次燃烧效率呈逐渐增高的趋势。

Abstract:

The swirl injection was introduced into ducted rocket designed to improve secondary combustion efficiency of ducted rocket. Three-dimensional reacting flow was numerically simulated, swirl air-in and gas swirl boron based ducted rocket was numerically simulated by means of Realizable k-ε turbulence model, one-step eddy-dissipation combustion mode1 and the ignition and combustion mode of boron particles of KING．The results show that when air swirl injection enters into secondary chamber, mixing and combustion finish more fully. When the cut-in angle increases, the secondary combustion efficiency increases firstly then falls. There is an angle value that makes secondary combustion efficiency the highest for a certain configuration of ducted rocket. For the motor studied, the angle is about 20°.When the swirl number for the gas from the gas generator increases, the secondary combustion efficiency also increases.