Transition Prediction in Incompressible Boundary Layer with Finite-Amplitude Streaks

Modulating the boundary layer velocity profile is a very promising strategy for achieving transition delay and reducing friction of plate. By perturbing flow with counter-rotating vortices that undergo transient, non-modal growth, streamwise-aligned streaks are formed inside layer, which have been proved (theoretical experimentally) to be robust structures. In this paper, we employ efficient numerical methods perform parametric stability investigation three-dimensional incompressible flat-plate finite-amplitude streaks. For purpose, Boundary Region Equations (BREs) applied solve nonlinear downstream evolution finite amplitude Regarding analysis, linear plane-marching Parabolized Stability (PSEs) concept constitutes best candidate task. Therefore, thorough study presented, analyzing instability characteristics respect critical conditions modified zero-pressure-gradient by means linearly optimal suboptimal disturbances or The parameter space extended from low- high- streaks, accurately documenting low-amplitude threshold streak shear bypass transition, drastically displaces front upstream.