Rayleigh-Taylor (RT) fluid turbulence through a bed of rigid, finite-size spheres is investigated by means of high-resolution direct numerical simulations, fully coupling the fluid and the solid phase via a state-of-the-art immersed boundary method. The porous character of the medium reveals a totally different physics for the mixing process...
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2018 (v1)PublicationUploaded on: April 14, 2023
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2016 (v1)Publication
The turbulent Rayleigh-Taylor system in a rotating reference frame is investigated by direct numerical simulations within the Oberbeck-Boussinesq approximation. On the basis of theoretical arguments, supported by our simulations, we show that the Rossby number decreases in time, and therefore the Coriolis force becomes more important as the...
Uploaded on: March 27, 2023 -
2007 (v1)Journal article
We offer a new example of conformal invariance far from equilibrium -- the inverse cascade of Surface Quasi-Geostrophic (SQG) turbulence. We show that temperature isolines are statistically equivalent to curves that can be mapped into a one-dimensional Brownian walk (called Schramm-Loewner Evolution or SLE$_\kappa$). The diffusivity is close to...
Uploaded on: December 4, 2022 -
2006 (v1)Journal article
Simplicity of fundamental physical laws manifests itself in fundamental symmetries. While systems with an infinity of strongly interacting degrees of freedom (in particle physics and critical phenomena) are hard to describe, they often demonstrate symmetries, in particular scale invariance. In two dimensions (2d) locality often promotes scale...
Uploaded on: December 4, 2022 -
2007 (v1)Book section
International audience
Uploaded on: November 30, 2023 -
August 25, 2006 (v1)Journal article
The small-scale statistics of homogeneous isotropic turbulence of dilute polymer solutions is investigated by means of direct numerical simulations of a simplified viscoelastic fluid model. It is found that polymers only partially suppress the turbulent cascade below the Lumley scale, leaving a remnant energy flux even for large elasticity. As...
Uploaded on: February 22, 2023 -
October 6, 2023 (v1)Journal article
We investigate the statistics of turbulence in emulsions of two immiscible fluids of the same density. We compute velocity increments between points conditioned to be located in the same phase or in different phases, and examine their probability density functions (PDFs) and the associated structure functions (SFs). This enables us to...
Uploaded on: January 24, 2024 -
2006 (v1)Journal article
Physics of Fluids, 18, p. 1702, http://dx.doi.org./10.1063/1.2349587
Uploaded on: December 3, 2022 -
2005 (v1)Journal article
The statistical geometry of dispersing Lagrangian clusters of four particles (tetrahedra) is studied by means of high-resolution direct numerical simulations of three-dimensional homogeneous isotropic turbulence. We give the first evidence of a self-similar regime of shape dynamics characterized by almost two-dimensional, strongly elongated...
Uploaded on: December 4, 2022