弹用固冲发动机可调喷管气膜冷却数值研究

Numerical Study on Film Cooling of Solid Ramjet Variable Nozzle for Missile

针对弹用固冲发动机鱼鳞片式可调收扩喷管进行气膜冷却研究,采用数值模拟的方法,研究了冷却气进口气流参数及冷却气进口环槽高度对冷却效果的影响。研究表明:冷却气流的总压须大于等于喷管主流总压;进口槽缝高度降低,冷却气流与主流掺混区贴近壁面,壁面气流温度较高;冷却气流和主流掺混区域与壁面不贴合时,随着飞行马赫数的增大,壁面气流温度反而略高。计算获得了能够保证喷管壁面温度低于800K、冷却气流量占主流流量7%的冷却方案,为固冲发动机可调喷管的设计打下基础。

The film cooling scheme of fish-scale variable convergent-divergent nozzle for solid rocket ramjet had been studied.The influences of inlet air flow parameters and inlet annular groove height of cooling gas on cooling effect are studied by numerical simulation.The results show that the total pressure of the cooling air must be greater than or equal to the total pressure of the main flow;the height of the inlet slot decreases,the cooling air and the main flow mixing zone are closer to the wall,and the wall air temperature is higher;when the cooling air and the main flow mixing zone do not fit the wall,the wall air temperature is slightly higher with the increase of flight Mach number.The cooling scheme which can ensure that the wall temperature of nozzle below 800 K and the cooling air flow accounts for 7%of the main flow is obtained,which lays a foundation for the design of variable nozzle of solid ramjet.