Oblique-mode breakdown in hypersonic and high-enthalpy boundary layers over a blunt cone

Autor: Xianliang Chen, Dongxiao Xu, Song Fu
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Advances in Aerodynamics, Vol 3, Iss 1, Pp 1-15 (2021)
Druh dokumentu: article
ISSN: 2524-6992
DOI: 10.1186/s42774-021-00076-9
Popis: Abstract The nonlinear analyses of the hypersonic and high-enthalpy boundary-layer transition had received little attention compared with the widely-studied linear instabilities. In this work, the oblique-mode breakdown, as one of the most available transition mechanisms, is studied using the nonlinear parabolized stability equations (NPSE) with consideration of the thermal-chemical non-equilibrium effects. The flow over a blunt cone is computed at a free-stream Mach-number of 15. The rope-like structures and the spontaneous radiation of sound waves are observed in the schlieren-like picture. It is also illustrated that the disturbances of the species mass and vibrational temperature near the wall are mainly generated by the product term of the wall-normal velocity disturbance and the mean-flow gradient. In comparison to the CPG flow, the TCNE effects destabilize the second mode and push upstream the N factor envelope. The higher growth rate of the oblique wave leads to stronger growth of the streamwise vortices and harmonic waves.
Databáze: Directory of Open Access Journals
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