Stabilization of the Hypersonic Boundary Layer by Finite-Amplitude Streaks

Authors: Ren, J., Fu, S., Hanifi, A.
Document Type: Article
Pubstate: Published
Journal: Physics of Fluids
Volume: 28(2)  
Year: 2016


Stabilization of two-dimensional disturbances in hypersonic boundary layer flows by finite-amplitude streaks is investigated using nonlinear parabolized stability equations. The boundary-layer flows at Mach numbers 4.5 and 6.0 are studied in which both the first- and second modes are supported. The streaks considered here are driven either by the so-called optimal perturbations (Klebanoff-type) or the centrifugal instability (Görtler-type). When the streak amplitude is in an appropriate range, i.e., large enough to modulate the laminar boundary layer but low enough to not trigger secondary instability, both the first- and second modes can effectively be suppressed.