Control of laminar streaks and Görtler vortices in pre-transitional boundary layers

Maintaining persistent laminar flow over high-speed vehicles and in supersonic wind-tunnel nozzles is essential: for vehicles, it minimizes friction drag and thermal load, while for wind tunnels, it ensures the development of facilities with low background turbulence. This thesis investigates the effects of active and passive control techniques on the receptivity and growth of laminar streaks and Görtler vortices in pre-transitional compressible boundary layers using asymptotic and numerical methods.