Abstract: Exhaust plume from the rocket engine produced strong infrared radiation signals， widely used for target detecting and identifying. For a model solid rocket motor， the Euler Discrete Phase model was used to describe the interaction between gases and solid particles. The detailed chemical reaction mechanism was used to calculate the afterburning in the plume. Based on the line by line integration method and Mie theory， the gases and solid particles radiation properties were solved. The radiation transmission was calculated by the light of sight method， and the applicability of the model was verified by the measured data. The effects of different flight heights on the gas-solid two-phase plume flow and radiation characteristics were simulated. The results show that： as the height increases， the interaction between the gas and the solid particles in the plume is weakened， and the larger the particle size， the greater the difference between the particles and the gas. The two-phase plume is affected by the difference in mixing and afterburning effects at different heights， resulting in significant differences in temperature and concentration of different gases. The radiation spectrum at each height exhibits a gas selective emission spectrum structure. The contribution of high temperature Al₂O₃ to radiation is mainly concentrated in short waves， and the higher the height， the smaller the influence. The radiation characteristics between different bands are affected by the emission bands of different gases， and the radiation peaks of the two main emission bands of 2.7μm and 4.3μm may appear at different flight heights.

Key words: Solid rocket motor;Two-phase flow;Exhaust plume;Flight height;Flow characteristics;Radiation characteristics

摘要： 针对某模型固体火箭发动机，基于欧拉离散相模型描述气-固两相相互作用，采用详细化学反应机理计算喷焰复燃效应，基于逐线积分法加米散射理论求解气体及粒子辐射物性参数，通过视在光线法计算辐射传输，并利用测量数据验证了模型的适用性，仿真分析了不同飞行高度对气固两相喷焰流动及辐射特性的影响。研究结果表明：随着飞行高度增加，喷焰中燃气与固体颗粒间相互作用减弱，且粒径越大的粒子与燃气间差异越大；两相喷焰受不同飞行高度上掺混与复燃效应程度差异的影响，致其温度分布和不同组分浓度分布存在显著差异；各高度下两相喷焰光谱辐射呈现气体选择性发射谱结构，其中高温Al₂O₃对辐射贡献主要集中在短波，且高度越高，影响越小；不同谱带间辐射特性受不同组分发射带影响而存在差异，且2.7μm和4.3μm两个主要发射带的辐射峰值出现在不同飞行高度。

关键词: 固体火箭发动机;两相流;喷焰;飞行高度;流场特性;辐射特性