航空学报 > 2025, Vol. 46 Issue (2): 130701-130701   doi: 10.7527/S1000-6893.2024.30701

预冷式超声速引射器启动和负载特性

梁涛, 徐万武(), 李智严, 张赛强, 李刚, 张冬冬()   

  1. 国防科技大学 空天科学学院 高超声速技术实验室,长沙 410073
  • 收稿日期:2024-05-17 修回日期:2024-06-14 接受日期:2024-07-31 出版日期:2024-08-06 发布日期:2024-08-05
  • 通讯作者: 徐万武,张冬冬 E-mail:zhangdd0902@163.com
  • 基金资助:
    国家自然科学基金(12002372);中国科协青年人才托举工程(2022QNRC001)

Starting and operating characteristics of precooled supersonic ejector

Tao LIANG, Wanwu XU(), Zhiyan LI, Saiqiang ZHANG, Gang LI, Dongdong ZHANG()   

  1. Hypersonic Technology Laboratory,College of Aerospace Science and Engineering,National University of Defense Technology,Changsha 410073,China
  • Received:2024-05-17 Revised:2024-06-14 Accepted:2024-07-31 Online:2024-08-06 Published:2024-08-05
  • Contact: Wanwu XU, Dongdong ZHANG E-mail:zhangdd0902@163.com
  • Supported by:
    National Natural Science Foundation of China(12002372);Young Elite Scientists Sponsorship Program by

摘要:

超声速引射器在航空航天领域具有广泛应用,一般用于抽吸被动流和产生低压环境。为提升超声速引射器性能,设计了一种新型预冷式超声速引射器。该引射器采用支板结构的双喷管,并引入预冷器来预冷温度超过1 100 K的被动流。基于试验和数值模拟相结合的方法,对预冷式超声速引射器的启动特性、负载特性以及预冷被动流对其性能的影响进行了分析。研究结果表明,当主动流总压超过3.0 MPa时,预冷式超声速引射器能够完全启动,盲腔压力稳定在3.46 kPa。而当引射器处于临界启动状态时,引射流道未达到超声速满流,激波串会影响盲腔压力。在完全启动状态下,两股射流自喷管加速流出后会相互撞击,喷管出口附近的静压呈现先上升再下降的趋势。而当引射器处于负载状态时,喷管出口附近的静压呈现先下降再上升的趋势。同时,无论是启动还是负载状态,引射流道均存在激波的交汇和反射,形成菱形激波区域,但随着被动流流量的增加和温度的提升,这些菱形区域逐渐消失。在低引射系数条件下,预冷被动流有效提升主被动流的混合效率,但在高引射系数下该优势不再凸显。此外,预冷被动流能有效提升引射器的增压比,提升幅度超过33.3%。

关键词: 超声速引射器, 预冷器, 启动特性, 负载特性, 激波

Abstract:

In the field of aerospace engineering, supersonic ejectors find extensive applications, typically for suctioning secondary flows and generating low-pressure environments. To enhance the performance of supersonic ejectors, this paper proposes a novel design of a precooled supersonic ejector. The ejector adopts a dual-nozzle structure with strut and uses a precooler to precool the secondary flows with temperatures exceeding 1 100 K. Through a combined approach of experimental and numerical methods, the starting characteristics, operating characteristics, and the influence of precooling secondary flows on the performance of the precooled supersonic ejector are analyzed. The research findings indicate that when the total pressure of the primary flow exceeds 3.0 MPa, the precooled supersonic ejector can start completely, with the suction chamber pressure becoming stabilized at 3.46 kPa. However, in the critical starting state, the ejector flow channels do not achieve full supersonic flow, and shock trains affect the suction chamber. In the fully started state, the two jets collide after accelerating out of the nozzles, leading to an initial rise followed by a decrease in static pressure near the nozzle exit. Conversely, when the ejector is in the operating mode, there is an initial decrease followed by an increase in static pressure near the nozzle exit. Additionally, regardless of starting or operating conditions, shockwave intersections and reflections exist in the ejector flow channels, forming diamond-shaped regions. These regions gradually disappear with an increase in the secondary flow rate and temperature of the regions. Under the condition of low entrainment ratio, precooling secondary flows effectively enhance the mixing efficiency of the primary and secondary flows, but this advantage diminishes at high ejector coefficients. Furthermore, precooled passive flows can effectively increase the compression ratio of the ejector, with the enhancement exceeding 33.3%.

Key words: supersonic ejector, precooler, starting characteristics, operating characteristics, shock wave

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