Published in Journal of Fluid Mechanics
Although the relative importance of airborne transmission of the SARS-CoV-2 virus is controversial, increasing evidence suggests that understanding airflows is important for estimation of the risk of contracting COVID-19. The data available so far indicate that indoor transmission of the virus far outstrips outdoor transmission, possibly due to lon...
Published in Journal of Fluid Mechanics
We perform direct numerical simulations of wall sheared Rayleigh–Bénard convection for Rayleigh numbers up to , Prandtl number unity and wall shear Reynolds numbers up to . Using the Monin–Obukhov length we observe the presence of three different flow states, a buoyancy dominated regime ( ; with the thermal boundary layer thickness), a transitional...
Published in Journal of Fluid Mechanics
Data from a direct numerical simulation for channel flow at a friction Reynolds number of 1000 are analysed to derive statistical properties that offer insight into the mechanisms by which large-scale structures in the log-law region affect the small-scale turbulence field close to the wall and the statistical skin-friction properties. The data com...
Published in Journal of Fluid Mechanics
An examination is undertaken of the validity and limitations of the quasi-steady hypothesis of near-wall turbulence. This hypothesis is based on the supposition that the statistics of the turbulent fluctuations are universal if scaled by the local, instantaneous, wall shear when its variations are determined from footprints of large-scale, energeti...
Published in Journal of Fluid Mechanics
The effect of permeability heterogeneities and viscosity variations on miscible displacement processes in porous media is examined using high-resolution numerical simulations and reduced theoretical modelling. The planar injection of one fluid into a fluid-saturated, two-dimensional porous medium with a permeability that varies perpendicular to the...
Published in Journal of Fluid Mechanics
A direct-numerical-simulation-based study is presented, which focuses on the response of near-wall turbulence and skin friction to the imposition of an oscillatory spanwise wall motion in channel flow. One point of contrast to earlier studies is the relatively high Reynolds number of the flow, namely Re
Published in Journal of Fluid Mechanics
Published in Journal of Fluid Mechanics
