Qinyang SONG, Ming DONG, Lei ZHAO
DOI Number: XXX-YYY-ZZZ
Conference number: HiSST2024-00223
Surface vibration, caused by either the mechanical action or the aeroelasticity, is a typical factor to
influence the boundary-layer transition over high-speed flying vehicles. This paper studies the evolution
of non-modal perturbations excited by low-frequency freestream vortical disturbances (FSVDs) in
hypersonic boundary layers with a spanwise vibrating wall. Under the framework of weakly nonlinear
theory, a high-fidelity numerical method based on the harmonic linearized Navier-Stokes equations is
developed to describe the boundary-layer response to the interaction of the FSVDs and the wall
vibration. When the non-modal perturbations accumulate to finite amplitude, the nonlinear parabolized
stability equations (NPSE) are employed to accommodate the nonlinear interaction among different
Fourier components, leading to the emergence of the secondary instability and eventually transition to
turbulence without the attendance of normal modes. It is found that the wall vibration would enhance
the strength of the streaks and the instability property of the secondary instability modes, leading to
premature of transition remarkably.