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Acta Aeronautica et Astronautica Sinica ›› 2024, Vol. 45 ›› Issue (24): 130408.doi: 10.7527/S1000-6893.2024.30408

• Fluid Mechanics and Flight Mechanics • Previous Articles     Next Articles

Mechanism of Bump inlet stable working at supersonic speed

Yu ZHU1, Jianhui CHENG1, Cheng CHEN2, Hexia HUANG2(), Huijun TAN2   

  1. 1.AVIC Shenyang Aircraft Design and Research Institute,Shenyang 110035,China
    2.College of Energy and Power Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China
  • Received:2024-03-18 Revised:2024-04-30 Accepted:2024-06-06 Online:2024-12-25 Published:2024-06-17
  • Contact: Hexia HUANG E-mail:huanghexia@nuaa.edu.cn
  • Supported by:
    Project of Advanced Jet Propulsion Innovation Center(HKCX2022-01-027);National Natural Science Foundation of China(12272177);Young Talents Scholar Lift Project(2021-JCJQ-QT-064)

Abstract:

To ensure the efficient matching of the supersonic Bump inlet with the engine across the entire flight envelope, this paper explores the dominant mechanism for enhancing its stable operational margin. Taking the four-lip forward-swept cowl Bump inlet as the subject of study, the evolution of the three-dimensional flow structure from supercritical to subcritical conditions at the designed Mach number is analyzed. The research findings indicate that under low mass flow (or high back pressure) conditions, the interaction between the normal shock and the boundary layer on the compression surface of the inlet, which combines a forward-swept cowl and a conical bump, generates a three-dimensional separation vortex that is expelled to the exterior of the inlet entrance. In contrast, an inlet with the same forward-swept cowl combined with a flat wedge experiences a “quasi-two-dimensional” flow separation under low mass flow conditions, with most of the separated flow being ingested into the inlet to result in a narrower stable margin as compared with the Bump inlet. Therefore, the generation of a three-dimensional separation vortex and its expulsion out of the entrance of the duct is the core mechanism for enhancing the aerodynamic performance of the Bump inlet and broadening its stable operational margin.

Key words: Bump inlet, shock wave/boundary layer interaction, separated flow, inlet-engine matching, flow control

CLC Number: