可渗透喷管动态工作特性数值研究

Numerical study on dynamic operating characteristics of permeable nozzle

可渗透喷管是一种新型的高度补偿喷管,能够实现自适应高度补偿,在单级入轨技术领域有重要研究意义。采用建立瞬态模型的方法对一定落压比范围的可渗透喷管进行数值模拟,通过动态分析,明确了可渗透喷管内部波系结构的生成及演化规律,并进行相关推力性能分析。研究结果表明:当NPR达到72.7时,喷管内出现无附着激波US。NPR较低时,US的产生机理为气动机理;NPR较高时,US的产生机理除气动机理外,还受到喷管壁面形状的影响。US激波起点在可渗透喷管内部时,喷管呈现推力补偿状态,反之则呈现推力损失状态。当NPR小于372.69时,可渗透喷管推力性能优于传统喷管。且可渗透喷管推力补偿最佳的工况是NPR等于70时,该工况下推力系数可提升24%以上。

Permeable nozzle is a new type of altitude compensation nozzle,which can achieve adaptive altitude compensation,which has important research significance in the field of single-stage orbit technology.In this paper,the method of establishing a transient model is used to numerically simulate the permeable nozzle in a certain pressure ratio range,and the generation and evolution law of the internal wave system structure of the permeable nozzle are clarified through dynamic analysis,and the relevant thrust performance analysis is carried out.The results show that when the NPR reaches 72.7,there is unattached shock US in the nozzle.When the NPR is low,the mechanism of US is pneumatic;When the NPR is high,the generation mechanism of US is affected by the shape of the nozzle wall in addition to the pneumatic mechanism.When the starting point of the US shock wave is inside the permeable nozzle,the nozzle shows a thrust compensation state,and vice versa.When the NPR is less than 372.69,the thrust performance of the permeable nozzle is better than that of the traditional nozzle.The best working condition for permeable nozzle thrust compensation is when NPR is equal to 70,and the thrust coefficient can be increased by more than 24%under this working condition.