侧向膨胀对单边膨胀喷管性能的影响研究

Investigation of Effects of Lateral Expansion on Performance of Single Expansion Ramp Nozzle

关键词:  三维非对称喷管  侧向膨胀  喷管性能  风洞试验

Key words:  Three dimensional asymmetrical nozzle  Lateral expansion  Nozzle performance  Wind tunnel test

摘要:

为研究侧向膨胀规律的变化对单边膨胀喷管性能的影响规律，运用三次曲线参数化方法给定不同的侧向膨胀规律，基于准二维特征线法设计得到相应的带侧向膨胀的三维非对称喷管构型，结合CFD计算结果，分析了直侧壁和曲侧壁两类侧壁型线对喷管性能的影响规律。为验证数值模拟方法的可靠性，选取具有10°膨胀角的直侧壁喷管进行风洞试验，数值模拟结果与实验结果吻合较好。研究结果表明:在给定的设计条件下，侧向膨胀角为6°时直侧壁喷管性能最优，该膨胀角可使喷管长度减短34.05%。侧向膨胀在保证喷管推力性能的同时，对减短喷管长度、减轻喷管重量具有重要意义；曲侧壁喷管侧壁面产生的推力变化趋势与整个喷管构型产生推力的变化趋势一致；“凸曲线”侧壁型线初始膨胀角较大，更有利于提高三维尾喷管的推力性能。

Abstract:

In order to investigate the effects of lateral expansion on the performance of single expansion ramp nozzle，different laws of lateral expansion were given by using cubic parametric approach，and the corresponding three-dimensional asymmetric nozzle configurations with lateral expansion were designed based on the quasi two-dimensional method of characteristics(MOC). Combined with CFD results，the effects of straight sidewalls and curved sidewalls on the performance of nozzle were further investigated. In order to verify the reliability of numerical simulation method，a cold flow wind tunnel experiment of the nozzle with 10° straight sidewalls was carried out. The results of the simulation are in good agreement with experiment data. The results show that，in the given design conditions，the nozzle with 6° straight sidewalls has optimal performance，and the nozzle’s length can be shortened by 34.05%. Lateral expansion can not only guarantee the performance of nozzle，but also be of great significance to shorten the length of nozzle and reduce its weight. For curved-sidewall nozzles，the trend of the thrust produced by sidewall is consistent with the thrust produced by the whole nozzle configuration. “Convex curve”is more helpful to improve the thrust performance of nozzle because of the larger initial expansion angle.