带侧向膨胀的三维非对称喷管设计和性能分析

针对带侧向膨胀的三维矩形截面非对称喷管，提出了一种基于准二维特征线法的喷管设计方法，获得了基于准二维特征线法的非对称喷管设计程序.然后，根据给定的几种侧向膨胀规律，通过该设计方法获得了相应的非对称喷管构型，并将该构型与通过优化算法获得的最优构型进行了比较，结果表明:两种方法所设计的非对称喷管的上、下壁面型面基本重合，喷管壁面压力分布趋势基本一致，验证了准二维特征线法的可靠性.与最优构型的性能相比，该方法所设计的喷管构型，推力偏差低于0.60%，升力偏差低于8.07%，且该设计法将设计耗时由30.5h减少到2h，可方便地应用到带侧向膨胀喷管的初期设计中. 

Design and performance analysis of the three-dimensional asymmetric nozzle with lateral expansion

Design method based on the quasi two-dimensional method of characteristics (MOC) was proposed for the three-dimensional (3-D) rectangular cross-section asymmetrical nozzle with lateral expansion. The corresponding asymmetrical nozzle design program based on MOC was obtained. Then, according to different lateral expansion laws, a series of asymmetrical nozzles were designed by using this method. And comparisons were made between these nozzles and the optimal configurations designed by optimization method. The comparisons show that:the up and down ramps of asymmetrical nozzles designed by the two methods are basically coincident and the pressure distributions on the expansion ramp are consistent, verifying the reliability of quasi-two-dimensional method of characteristics; the difference in thrust between the MOC design and the optimization design is lower than 0.60% and in lift is lower than 8.07%. This design method can reduce the time spent by the design from 30.5h to 2h, presenting a satisfactory approach for the preliminary design.