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本文发展了一个双基推进剂侵蚀燃烧的综合气动热化学模型,分析中包括了对燃烧过程的详细模拟,在气相反应中同时考虑了化学动力学作用与扩散作用,并以三种反应来代表嘶嘶区和终焰区(包括暗区和明亮火焰区)的情况。瞬态偏微分控制方程组采用费弗(Favre)平均以考虑变密度影响。湍流反应边界层模型由两方程(k—ε)湍流闭合模型和费弗平均后的诸守恒方程组成。控制方程组由数值方法求解。对一种不含催化剂的双基推进剂的侵蚀燃速的理论计算结果与布立克(Burick)和奥斯本(Osborn)的实验结果相比较吻合得很好。计算的边界层内温度分布正确地描述了双基推进剂的燃烧特点。理论分析表明,侵蚀燃速增大的主要机理是湍流加强了嘶嘶区内的传递特性和化学反应,导致对燃烧表面热量回传增加的结果。
In this paper, a comprehensive aerodynamic thermochemical model of erosive combustion of double-base propellants is developed. The analysis includes a detailed simulation of the combustion process, taking into account both chemical kinetic and diffusion effects in the gas-phase reaction, represented by three reactions Hysterical and final flame zones (including dark and bright flames). The transient partial differential governing equations use a Favre average to account for variable density effects. The turbulent response boundary layer model consists of two equations (k-ε) turbulence closed model and Faveh’s averaged conservation equations. Control equations are solved numerically. The theoretical calculation of the erosive combustion rate of a catalyst-free double base propellant is in good agreement with the experimental results of Burick and Osborn. The calculated temperature distribution in the boundary layer correctly describes the combustion characteristics of the two-base propellant. Theoretical analysis shows that the main mechanism of the increase of erosion burning rate is that turbulence enhances the transfer characteristics and chemical reactions in the hysteric zone, resulting in the increase of heat transfer back to the combustion surface.