Direct numerical simulation of supersonic boundary layers over a microramp: effect of the Reynolds number

Microvortex generators are passive control devices smaller than the boundary layer thickness that energise the boundary layer to prevent flow separation with limited induced drag. In this work, we use direct numerical simulations (DNS) to investigate the effect of the Reynolds number in a supersonic turbulent boundary layer over a microramp...

Low-frequency unsteadiness mechanisms in shock wave/turbulent boundary layer interactions over a backward-facing step

The low-frequency unsteady motions behind a backward-facing step (BFS) in a turbulent flow at and are investigated using a well-resolved large-eddy simulation. The instantaneous flow field illustrates the unsteady phenomena of the shock wave/boundary layer interaction (SWBLI) system, including vortex shedding in the shear layer, the flapping...

Boundary-layer stability of supercritical fluids in the vicinity of the Widom line

We investigate the hydrodynamic stability of compressible boundary layers over adiabatic walls with fluids at supercritical pressure in the proximity of the Widom line (also known as the pseudo-critical line). Depending on the free-stream temperature and the Eckert number that determines the viscous heating, the boundary-layer temperature...

Scaling and modelling of turbulence in variable property channel flows

We derive an alternative formulation of the turbulent kinetic energy equation for flows with strong near-wall density and viscosity gradients. The derivation is based on a scaling transformation of the Navier-Stokes equations using semi-local quantities. A budget analysis of the semi-locally scaled turbulent kinetic energy equation shows that...

A scaling analysis for turbulent shock-wave/boundary-layer interactions

A model based on mass conservation properties is developed for shock-wave/boundarylayer interactions (SWBLIs), aimed at reconciling the observed great diversity in flow organization documented in the literature, induced by variations in interaction geometry and aerodynamic conditions. It is the basis for a scaling approach for the interaction...