Transition under elevated free-stream turbulence
Elevated free-stream turbulence accelerates the process of laminar-to-turbulent transition by the selective inclusion of low-frequency disturbances into the boundary layer. As these amplify, they form longitudinal streaks that rapidly break-down into localized regions of turbulence that resemble the turbulent spots studied here under low free-stream turbulence. The manner in which free-stream turbulence alters the spot-growth […]
Laminar-to-turbulent transition in separation bubbles
The transition of fluid flows from a laminar behaviour to turbulence–referred to as laminar-to-turbulent transition–is one of the chief difficulties in classical physics. While laminar flows are orderly, turbulence involves irregular velocity fluctuations over a wide range of spatial and temporal scales. The fluctuations enhance the transfer of momentum and energy so that the drag […]
Instability of planar free shear layers
The instability of planar free shear layers is an important consideration in a broad range of applications, such as heat exchangers, chemical reactors, building wakes, and aerofoils. A planar free shear layer is primarily unstable through an inviscid Kelvin-Helmholtz mode that exists due to the inflectional shape of the shear-layer velocity profile. The OKCFD Lab performs detailed numerical research […]