带侧向膨胀的三维非对称喷管设计和性能分析

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

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 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 asym- metrical nozzles were designed by using this method. And comparisons were made between these nozzles and the optimal configurations designed by optimization method. The compari- sons 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 consist- ent, 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 30.5 h to 2h, presenting a satisfactory approach for the preliminary design.