Buoyancy-Driven Flow through a Bed of Solid Particles Produces a New Form of Rayleigh-Taylor Turbulence
Journal article, 2018

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 when compared to the well-known phenomenology of classical RT mixing. For sufficiently small porosity, the growth rate of the mixing layer is linear in time (instead of quadratical) and the velocity fluctuations tend to saturate to a constant value (instead of linearly growing). We propose an effective continuum model to fully explain these results where porosity originated by the finite-size spheres is parametrized by a friction coefficient.


Gaetano Sardina

Chalmers, Mechanics and Maritime Sciences, Fluid Dynamics

Royal Institute of Technology (KTH)

Luca Brandt

Royal Institute of Technology (KTH)

G. Boffetta

University of Turin

A. Mazzino

University of Genoa

Physical Review Letters

0031-9007 (ISSN) 1079-7114 (eISSN)

Vol. 121 22 224501

Driving Forces

Sustainable development

Subject Categories

Applied Mechanics

Computational Mathematics

Fluid Mechanics and Acoustics

Areas of Advance




Basic sciences



More information

Latest update

1/3/2019 9