A comprehensive investigation is carried out to establish best practice guidelines for the modelling of statistically steady-state non-neutral urban boundary layers (UBL) using large-eddy simulation (LES). These steady-state simulations enable targeted studies under realistic non-neutral conditions without the complications associated with the inhe...
A non-linear eddy-viscosity transition model is presented, tuned by a large experimental data set describing transitional boundary layers. Data have been acquired by TR-PIV on a flat plate placed in a 2D converging-diverging channel with variable opening angle, allowing variation of the adverse pressure gradient, the free-stream turbulence intensit...
Alfvénic fluctuations in solar wind are an intrinsic property of fast streams, while slow intervals typically have a very low degree of Alfvénicity, with much more variable parameters. However, sometimes a slow wind can be highly Alfvénic. Here we compare three different regimes of solar wind, in terms of Alfvénic content and spectral properties, d...
This work deals with buoyant tracers floating at the ocean surface, where the geostrophic velocity component is 2D and rotational (non-divergent), and the ageostrophic component can contain comparable in size rotational and potential (divergent) contributions. We consider a random kinematic flow model and study the process of clustering, that is, a...
Sub-mesoscale fronts—with scales from 1 to 50 km are ubiquitous in satellite images of the world oceans. They are known to generate strong vertical velocities with significant impacts on biogeochemical fluxes and pelagic ecosystems. Here, we use a unique data set, combining high-resolution behavioral and physical measurements, to determine the effe...
The energy needed to drive airflow through the trachea normally constitutes a minor component of the work of breathing. However, with progressive tracheal compression, patient subjective symptoms can include severe breathing difficulties. Many patients suffer multiple respiratory co-morbidities and so it is important to assess compression effects w...
This paper presents results of JET ITER-like wall L-mode experiments in hydrogen and deuterium (D) plasmas, dedicated to the study of the isotope dependence of ion heat transport by determination of the ion critical gradient and stiffness by varying the ion cyclotron resonance heating power deposition. When no strong role of fast ions in the plasma...
In a first moment we will be interested in the recovery of the mean-flow quantities from partial or sparse information, ranging from point-wise velocity probes to wall-pressure and friction. This will be achieved by considering the Reynolds-Averaged Navier-Stokes (RANS) equations, completed with a model, here the Spalart-Allmaras. This kind of mode...
We investigate the effect of the wall-scalar fluctuations on passive scalar turbulent fields for a moderate Reynolds number R τ = 395 and for several Prandtl numbers ranging from the very low value P r = 0.01 to the high value P r = 10 by means of DNS simulations. Several cases of plane channel flows are considered. Case I is a channel flow heated ...
