固体火箭冲压发动机绝热层传热特性数值仿真

摘要

研究冲压发动机补燃室的热防护性能,为发动机长时间安全工作提高热防护技术,建立了补燃室三维流场和EPDM(三元乙丙)绝热层的物理数学模型,数值仿真补燃室内燃烧及流动过程.对补燃室内温度变化梯度大,燃气温度在补燃室中部达到极值,化学反应流场在周向存在很大的不对称性.补燃室头部的回流区和输运漩涡对燃烧效率有着重要影响.通过对绝热层和壳体的温度场进行数值仿真,发现绝热层存在两个高温区域:头部回流区域和补燃室中部的燃烧充分区域.计算结果符合物理规律,并与试验结果符合较好.研究结果为冲压发动机补燃室热防护层的设计提供了有效的分析手段.%In order to study thermal - protection function of solid ducked rocket secondary combustion chamber, 3 - D physical and mathematical models of flow field and EPDM insulation were established. Flow field in secondary combustion chamber was simulated. Results show that the temperature gradient of the secondary combustion chamber is large. The highest temperature zone locates in the middle of the secondary combustion chamber. The flow field pa-rameters are asymmetrical. The eddy motion which locates in the front of the secondary combustion chamber and transported swirl has a very important effect on the combustion efficiency. The temperature fields of insulation and metal shell were simulated. It is shown that there are two high temperature zones on the insulation: one locates in the front of the secondary combustion chamber where the eddy motion exits and the other one locates in the middle of the secondary combustion chamber. The calculated result fits physics law, and it fits better with the test result. This re-search offers an effective analytical method for insulation design in the solid ducked rocket secondary combustion chamber.