激光辐射下AP/HTPB复合推进剂低压燃烧特性数值模拟

Numerical Simulation of Low Pressure Combustion Characteristics of AP/HTPB Composite Propellant under Laser Radiation

关键词:  激光辐射  复合推进剂  低压燃烧特性  激光助燃  自持燃烧

Key words:  Laser radiation  Composite propellant  Low pressure combustion characteristics  Laser-assisted combustion  Self-sustained combustion

摘要:

为了研究激光辐射对AP/HTPB复合推进剂低压燃烧的作用机理，建立二维三明治稳态燃烧模型进行数值仿真研究。针对激光辐射强度1.4W/mm²，压强30~90kPa的工况下推进剂的燃烧进行仿真计算，并与130~160kPa压强下自持燃烧的仿真结果进行差异分析。结果表明，激光助燃工况下，仿真计算所得燃速与实验基本一致，最大误差不超过4.2%。在激光助燃和自持燃烧工况下，组分扩散速度快，气相火焰均为预混结构。激光助燃工况下，激光辐射的能量使得近燃面处的反应比较充分，初扩散反应在气相反应中占主导地位，气相火焰高温区域离燃面近；自持燃烧工况下，AP预混反应和初扩散反应共同主导气相反应过程，气相火焰温度在垂直于燃面方向上增长缓慢且高温区域离燃面远。激光助燃比自持燃烧时的压强指数低，推进剂燃烧对压强的敏感性较弱。

Abstract:

In order to study the mechanism of laser radiation on low pressure combustion of AP/HTPB composite propellant， a two-dimensional sandwich steady-state combustion model was used for numerical simulation. The simulation calculation was carried out under the condition of laser radiation intensity of 1.4W/mm² and pressure of 30~90kPa， and compared with the simulation results of self-sustained combustion under the pressure of 130~160kPa. The results show that the burning rate calculated by simulation is basically consistent with the experiment， and the maximum error is no more than 4.2%. Under the conditions of laser-assisted combustion and self-sustained combustion， the component diffusion is fast， and the gas phase is premixed structure. Under the laser-assisted combustion condition， the energy of laser radiation makes the reaction near the burning surface more sufficient， the initial diffusion reaction is dominant in the gas phase reaction， and the high temperature region of the gas phase flame is close to the burning surface. Under the self-sustained combustion condition， AP premix reaction and initial diffusion reaction jointly dominate the gas-phase reaction process. The gas-phase flame temperature increases slowly in the direction perpendicular to the combustion surface， and the high temperature area is far from the combustion surface. The pressure exponent of laser-assisted combustion is lower than that of self-sustained combustion， and the combustion of propellant is less sensitive to pressure.