来流条件对SFRJ燃速及自持燃烧性能的影响

为了研究来流条件对固体燃料燃速以及自持燃烧性能的影响规律,采用3阶单调迎风格式(MUSCL)重构方法,AUSMPW⁺通量分裂格式,k-w剪切应力输运(SST)湍流模型,7组分3反应有限速率化学反应模型以及2阶矩湍流燃烧模型,编制了二维轴对称湍流燃烧仿真程序。仿真结果显示:来流质量流率和总温的增加会提高燃速,温度和质量通量的影响指数大约为0.95~1.00和0.67;来流条件影响燃速的主要机理是壁面附近温度和湍流黏性的变化,其中湍流黏性是主要影响因素;随着质量流率的增加,特征速度逐渐降低,当入口马赫数接近1时,特征速度大约为850 m/s,固体燃料将无法自持燃烧。

Effect of inlet flow condition on regression rate and self-sustained combustion of solid fuel ramjet

In order to investigate the influence of inlet flow condition on regression rate and self-sustained combustion of solid fuel ramjet, a 2d axisymmetric turbulent flow and combustion program is developed. The equation is solved using MUSCL reconstruction method and AUSMPW⁺ flux splitting technique, with k-w shear stress transport (SST) turbulence model, 7 species/3 reaction kinetics finite rate model and second-order moment turbulence-chemistry model. The simulation results show that the increases of air mass rate and total temperature enhance the regression rate and the exponents for them are 0.95-1.00 and 0.67. The variation of regression rate for different inlet flow conditions is caused by the variation of temperature and turbulent viscosity while turbulent viscosity is the predominant factor. Characteristic velocity decreases with the increase of air mass rate. The characteristic velocity is about 850 m/s and combustion could not sustain when the Mach number at inlet reaches about 1.