航空学报 > 2025, Vol. 46 Issue (8): 631009-631009   doi: 10.7527/S1000-6893.2024.31009

两级膨胀喷管设计方法及数值模拟

裴文倩, 俞凯凯(), 刘增旭, 宁琪月, 徐惊雷   

  1. 南京航空航天大学 能源与动力学院,南京 210016
  • 收稿日期:2024-07-30 修回日期:2024-08-21 接受日期:2024-09-20 出版日期:2024-09-27 发布日期:2024-09-25
  • 通讯作者: 俞凯凯 E-mail:yukk@nuaa.edu.cn
  • 基金资助:
    航空发动机及燃气轮机基础科学中心项目(P2022-B-I-006-001)

Two-stage expansion nozzle design method and numerical simulation

Wenqian PEI, Kaikai YU(), Zengxu LIU, Qiyue NING, Jinglei XU   

  1. College of Energy and Power Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China
  • Received:2024-07-30 Revised:2024-08-21 Accepted:2024-09-20 Online:2024-09-27 Published:2024-09-25
  • Contact: Kaikai YU E-mail:yukk@nuaa.edu.cn
  • Supported by:
    Aviation Engine and Gas Turbine Basic Science Center(P2022-B-I-006-001)

摘要:

为了提升宽空域(0~24 km)、宽速域(马赫数0~5)内喷管的性能,利用高度补偿和反设计概念进行了两级膨胀喷管设计方法的研究。首先,介绍了两级膨胀喷管的设计方法和步骤,两级膨胀喷管型线分为基础段和延伸段型线,其中基础段型线利用基于壁面压力的反设计方法生成,以此来改变激波位置和强度进而缩短喷管负推力面,达到在低速飞行状态下提高喷管推力性能的目的;喷管延伸段型线采用基于强几何约束的最大推力喷管设计方法,满足高超声速飞行器后体一体化设计目的。其次,为了验证所提设计方法的有效性,采用数值模拟方法对提出的设计方法进行了研究,在此过程中,介绍并验证了数值计算方法并确定了网格分辨率。进一步,对控制壁面压力分布反设计喷管基础段型线的设计方法进行了验证,并实现了激波前移/后移的目标。同时,对关键设计参数——位置控制因子和压力控制因子对喷管的性能影响开展了研究。最后,为验证所提设计方法的有效性和优越性,将其与全几何约束的最大推力喷管设计方法进行对比分析。结果表明,在典型设计工况下该喷管相对于全几何约束的最大推力喷管在过膨胀状态下推力性能提高了7.86%,而在欠膨胀状态下推力性能只降低了0.75%,为高超声速飞行器排气系统提供了理论基础。

关键词: 两级膨胀, 正反设计, 特征线法, 全几何约束, 最大推力理论

Abstract:

To enhance the performance of the nozzle in a wide airspace (0–24 km) and wide speed domain (Mach number 0–5), a two-stage expansion nozzle design methodology is investigated by utilizing altitude compensation and inverse design concepts. Firstly, the design method and steps of the two-stage expansion nozzle are introduced. The two-stage expansion nozzle profiles are divided into the base section and extension section profiles. The base section profiles are generated by the reverse design method based on the wall pressure, which is used to shorten the negative thrust surface of the nozzle by changing the position and strength of the shock wave and to improve the thrust performance of the nozzle under the low-speed flight condition. The nozzle extension profile adopts the maximum thrust nozzle design method based on strong geometric constraints to meet the purpose of hypersonic vehicle afterbody integration design. Secondly, the validity of the proposed design methodology is verified using numerical simulation, in which the numerical calculation methodology is introduced and verified, and the grid resolution is determined. Further, the design method for the reverse design of nozzle base profile for controlling wall pressure distribution is validated, and the goal of forward/backward shifting of the shock wave is achieved. At the same time, a study is conducted on the influence of the two key design parameters, i. e., the position control factor and the pressure control factor, on the the performance of the nozzle. Finally, comparative analysis of the proposed method and the maximum thrust nozzle design method with full geometric constraints is performed to verify the effectiveness and superiority of the new method. The results show that compared to the fully geometrically constrained maximum-thrust nozzle, the nozzle designed with the proposed method improves the thrust performance by 7.86% in the over-expansion state and decreases the thrust performance by only 0.75% in the under-expansion state under typical design conditions, which provides a theoretical basis for the design of the exhaust system of hypersonic vehicles.

Key words: two-stage expansion, forward and reverse design, method of characteristics, full geometric constraint, maximum thrust theory

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