Alfv\'en vortex is a multi-scale nonlinear structure which contributes to intermittency of turbulence. Despite previous explorations mostly on the spatial properties of the Alfv\'en vortex (i.e., scale, orientation, and motion), the plasma characteristics within the Alfv\'en vortex are unknown. Moreover, the connection between the plasma energizati...
A procedure to accurately simulate a free hot supersonic jet and its associated noise, which uses simultaneously a turbulence tripping method and a two-way coupling between a flow solver and a nonlinear acoustic solver, is proposed in this study. A Mach 3.1 overexpanded hot jet is computed via a large-eddy simulation by solving the filtered Navier-...
In this study we generate optimal Runge-Kutta (RK) schemes for converging the Artificial Compressibility Method (ACM) using dual time-stepping with high-order unstructured spatial discretizations. We present optimal RK schemes with between s = 2 and s = 7 stages for Spectral Difference (SD) and Discontinuous Galerkin (DG) discretizations obtained u...
The near wakes of flows past single- and multi-scale arrays of bars are studied by means of planar laser induced fluorescence (PLIF) and particle image velocimetry (PIV). The aim of this research is to better understand dispersion of passive scalar downstream of the multi-scale turbulence generator. In particular, the focus is on plausible manifest...
Confluences play a major role in the dynamics of networks of natural and man-made open channels, and field measurements on river confluences reveal that discordance in bed elevation is common. Studies of schematized confluences with a step at the interface between the tributary and the main channel bed reveal that bed elevation discordance is an im...
© 2018 The Combustion Institute. Focusing on advancing predictive fire modeling, large eddy simulations using improved approaches related to thermophysical, turbulence, combustion and radiation modeling are presented. More specifically, the consideration of a non-unity Lewis number, the use of the Hirschfelder-Curtiss diffusion model, the inclusion...
We prove that statistically stationary martingale solutions of the 3D Navier-Stokes equations on 3 subjected to white-in-time (colored-in-space) forcing satisfy the Kolmogorov 4/5 law (in an averaged sense and over a suitable inertial range) using only the assumption that the kinetic energy is o(ν−1) as ν→0 (where ν is the inverse Reynolds number)....
Une couche limite turbulente se développant le long d'une paroi présente des fluctuations de vitesses et de pression importantes. Si la paroi du profil est suffisamment souple, les fluctuations de pression pariétale peuvent la faire rentrer en vibration ce qui induit un rayonnement acoustique de chaque côté de la paroi. Ce scenario est l'un des méc...
A new set of exact coherent states in the form of a travelling wave is reported in plane channel flow. They are continued over a range in Re from approximately 2600 up to 30 000, an order of magnitude higher than those discovered in the transitional regime. This particular type of exact coherent states is found to be gradually more localised in the...
