UBC-Okanagan Computational Fluid Dynamics Laboratory

Okanagan Computational Fluid Dynamics Laboratory

Laminar-to-turbulent transition on a plate with a blunt leading edge
Video of laminar-to-turbulent transition on a plate with a blunt leading edge. A favorable/adverse pressure distribution is imposed by a contoured ceiling. Iso-contours of the Lambda2-criterion illustrate the onset of turbulence due to separated-flow transition near the blunt leading edge, dampening of the turbulent structures by the flow acceleration, and re-amplification by the flow deceleration. […]
Laminar-to-turbulent transition on a NACA0018 airfoil
Laminar-to-turbulent transition on a NACA0018 airfoil at Re = 100,000 and 5 degrees incidence. Iso-contours are Q-criterion coloured by streamwise velocity. Airfoil surface is shaded with instantaneous wall shear stress.
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 […]
Growth mechanisms of a turbulent spot
Hairpin-like vortices have been identified as the dominant coherent flow structures in transitional and turbulent boundary layers and free shear layers. To better understand the characteristics of these flows, it is important to study the creation and growth mechanisms of the hairpin vortices and the resultant wave packets containing multiples of these flow structures. A turbulent spot in […]

The UBC-Okanagan Computational Fluid Dynamics (CFD) Laboratory has a focus on performing computational research on fundamental questions in fluid mechanics. The primary research focus is on how flow instabilities, transition, and turbulence affects the performance and efficiency of the turbomachinery equipment used in the aerospace, nuclear, and energy industries. I am further interested in the simulation of multiphase turbulent flows, wind energy systems, compressed and liquefied natural gas (CNG and LNG) systems, hydrogen storage, hydrogen blending and safety, and buildings employing passive ventilation technologies.

Laminar-to-turbulent transition on a plate with a blunt leading edge

Laminar-to-turbulent transition on a NACA0018 airfoil

Transition under elevated free-stream turbulence

Laminar-to-turbulent transition in separation bubbles

Instability of planar free shear layers

Growth mechanisms of a turbulent spot