高含铝推进剂低压固体火箭发动机尾流场复燃数值模拟与实验研究

Numerical Simulation and Experimental Investigation on Plume Afterburning of Low-Pressure Solid Rocket Motor with Highly Aluminized Propellant

关键词:  含铝推进剂  低压  固体火箭发动机  尾流场  复燃

Key words:  Aluminized-propellant  Low-pressure  Solid rocket motor  Exhaust plume  Afterburning

摘要:

为研究高含铝推进剂低压固体火箭发动机的尾流场特性，利用流体计算软件Fluent，采用三维雷诺平均N-S方程和标准k-ε湍流模型，对高含铝固体推进剂低压发动机尾流场复燃进行了数值模拟和实验研究。结果表明:低压下高含铝固体推进剂羽流复燃时，温度分布呈现“双峰”的现象，第一温峰是纯气相燃烧形成的，第二温峰是铝粒子燃烧形成的；且铝粒径越小，第二温峰出现的位置离喷管越近，铝粒子温度越高，最高可达1124K；燃烧室压强越高，第二温峰出现的位置离喷管越远。发动机试车试验中也出现“双峰”的羽流温度场，且测得粒子最高温度为1141K，与模拟结果吻合较好。

Abstract:

In order to study the combustion characteristics of the exhaust plume in a low-pressure solid rocket motor with highly-aluminized propellant，the afterburning behavior at low combustion pressure in the exhaust plume of a solid rocket motor with highly-aluminized propellant was simulated through the establishment of three-dimensional Reynolds-averaged N-S equations and the standard k-ε model by way of the computational fluid dynamics software (Fluent) and verified by experimental tests. The simulation results show that the temperature distribution of afterburning plume with highly-aluminized solid propellant under low pressure appears dual temperature peaks when the afterburning considered. The first peak is produced by the combustion of the gas components，while the second one by aluminum particles. The position where the second peak appears will be closer to the nozzle as the particle sizes of aluminum get smaller，so does the maximum temperature of particles，which can reach up to 1124K. In the meanwhile，when the chamber pressure gets higher，the second peak will appear further to the nozzle. The results obtained are of accordance with those of the solid rocket motor experimental results，which shows similar dual temperature peaks and the maximum temperature of particles of 1141K in the plume.