WG
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- Professor
- Supervisor of Doctorate Candidates
- Supervisor of Master's Candidates
- Name (English):Wang Ge
- Name (Pinyin):WG
- School/Department:航天与建筑工程学院
- Degree:Doctoral Degree in Engineering
- Professional Title:Professor
- Status:Employed
- Teacher College:College of Aerospace and Civil Engineering
- Discipline:Fluid Mechanics
Aeronautical and Astronautical Science and Technology
Contact Information
- OfficePhone：
- Telephone：
- Email：
- 0451-82519202：
- 13019008393：
- wangge@hrbeu.edu.cn：
- ZipCode：
- PostalAddress：
- Paper Publications
Experimental study on startup-shutdown process of a planar expansion deflection nozzle
Release time:2025-11-06 Hits:
- Impact Factor:5.7
- DOI number:10.1016/j.cja.2025.103471
- Affiliation of Author(s):哈尔滨工程大学
- Journal:CHINESE JOURNAL OF AERONAUTICS
- Place of Publication:中国
- Key Words:Cold-flow experiment；Expansion deflection nozzle；Mode transition；Shock flapping；Shock waves
- Abstract:Cold-flow experiments on planar Expansion Deflection (ED) nozzle flows are conducted under a simulated startup-shutdown process of rocket motors. The purpose is to investigate the flow and performance characteristics in ED nozzles, capture the behavior of shock flapping, and explore asymmetric flow dynamics utilizing a symmetric nozzle. A total pressure condition, characterized by rapid rise followed by a slow fall, is employed to simulate the continuous startup and shutdown processes. The schlieren imaging technique and high-frequency pressure transducers are employed to obtain the flow information. The experimental results indicate that the flow characteristics differ between the startup and shutdown processes with a hysteresis observed in the nozzle wake mode transition. During the startup process, the shock waves are pushed outward of the nozzle, while during the shutdown process, the flow propagates inward dominated by Mach stems. Counterintuitive results are demonstrated, namely, the mode transition is not the cause of the sudden thrust decrease, and the moment of maximum thrust does not coincide with the moment of maximum total pressure. During the operation of the nozzle, two stages of shock wave flapping occur, accompanied by significant wall pressure oscillations. These oscillation frequencies are demonstrated to be related to the inherent acoustic frequencies of the test chamber. An improved pressure ratio method is proposed to predict the position of the shock oscillation separation point. The prediction results revealed the shock behavior during the flapping process.
- Indexed by:Journal paper
- Discipline:Engineering
- Document Type:J
- Volume:38
- Issue:7
- Translation or Not:no
- Date of Publication:2025
- Included Journals:SCI