Flow structures and unsteadiness in hypersonic shock wave/turbulent boundary layer interaction subject to steady jet

• Published in: Acta mechanica Sinica Vol. 39; no. 12
• Main Authors: Liu, Qiang, Xie, Wei, Luo, Zhenbing, Sun, Mingbo, Cheng, Pan, Deng, Xiong, Zhou, Yan
• Format: Journal Article
• Language: English
• Published: Beijing The Chinese Society of Theoretical and Applied Mechanics; Institute of Mechanics, Chinese Academy of Sciences 01.12.2023; Springer Nature B.V
• Edition: English ed.
• Subjects: Boundary layer interaction; Boundary layer thickness; Classical and Continuum Physics; Coefficient of friction; Computational Intelligence; Direct numerical simulation; Engineering; Engineering Fluid Dynamics; Flow control; Flow separation; Hypersonic flow; Hypersonic shock; Power spectral density; Research Paper; Shock wave interaction; Skin friction; Stanton number; Theoretical and Applied Mechanics; Turbulence; Turbulent boundary layer; Wall pressure; Unsteadiness; Direct numerical simulation; STBLI; Steady jet; Hypersonic flow; Pressure fluctuating; Flow structure
• ISSN: 0567-7718; 1614-3116
• DOI: 10.1007/s10409-023-23202-x

Direct numerical simulations of Mach 6 hypersonic flow over a 34° compression corner subject to steady jet are conducted. Distributions of skin friction coefficient, wall pressure, mean velocity and temperature, boundary layer thickness and Stanton number demonstrate that the flow changes dramatically in the shock wave/turbulent boundary layer interaction area. It is found that the steady jet has no effect on suppressing flow separation unexpectedly, but increases its spatial scale instead. Instantaneous flow structures show that the turbulence amplification can be observed after the application of flow control, and abundant Gortler-like vorticities appear, but the strength of the main shock decreases. Analyzing the wall fluctuating pressure signals using weighted power spectral density, we found an interesting thing. That is, although the low-frequency oscillation phenomenon induced by separation shock is suppressed by the steady jet, wall fluctuating pressure beneath the jet shock is oscillating at a frequency lower than 0.1 u ∞ / δ ref . Results of coherent and intermittency factor reveal that it is related to the backand- forth movement of the jet shock itself.