几何尺寸约束的超燃冲压发动机推力喷管设计

New design method for scramjet nozzles with strong geometric constraints

针对机体/推进系统一体化要求,提出了一种几何尺寸约束的超燃冲压发动机推力喷管设计方法,以实现在满足几何约束条件下优化喷管的气动性能。采用数值模拟对提出的设计方法展开了研究,在此过程中,首先校核了数值方法有效性并确定了网格分辨率。进一步就喷管设计过程中2个关键设计因子——比例因子和非对称因子开展了影响研究。最后为验证本文提出的设计方法的有效性和优越性,将其与典型截短设计方法进行对比分析。结果表明,相比截短方法,本文提出的设计方法不仅能够获得满足几何约束的喷管,同时可使喷管推力系数、升力和俯仰力矩分别提升33.36%、265.75%和37.21%。此外,本文提出的设计方法还可以通过调整设计因子来获得不同气动性能的喷管,进而满足应用过程中的实际需求。

In view of the requirement of nozzle/afterbody integration,a new design method for scramjet nozzles with geometric constraints is proposed to optimize the nozzle aerodynamic performance.The proposed design method is investigated using numerical simulation,and its validity attested.Furthermore,the grid resolution is determined.The influence study of the two key design factors in the nozzle design process,i.e.,the proportional factor and the asymmetric factor,is then conducted.Finally,comparative analysis of the proposed method and the typical truncation method is performed to verify the effectiveness and superiority of the new method.The results show that the new design method can obtain a nozzle satisfying the geometric constraints with the thrust coefficient,the lift,and the pitch moment increasing by 33.36%,265.75% and37.21%respectively.In addition,the design factors of this method can be adjusted to obtain nozzles with different aerodynamic performance to meet the actual requirements of the application.