Buoyancy-Driven Flow through a Bed of Solid Particles Produces a New Form of Rayleigh-Taylor Turbulence.

@article{Sardina2018BuoyancyDrivenFT,
  title={Buoyancy-Driven Flow through a Bed of Solid Particles Produces a New Form of Rayleigh-Taylor Turbulence.},
  author={Gaetano Sardina and Luca Brandt and Guido Boffetta and Andrea Mazzino},
  journal={Physical review letters},
  year={2018},
  volume={121 22},
  pages={
          224501
        }
}
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… 

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References

SHOWING 1-10 OF 54 REFERENCES

Turbulent channel flow of dense suspensions of neutrally buoyant spheres

Abstract Dense particle suspensions are widely encountered in many applications and in environmental flows. While many previous studies investigate their rheological properties in laminar flows,

Incompressible Rayleigh–Taylor Turbulence

Basic fluid equations are the main ingredient in the development of theories of Rayleigh–Taylor buoyancy-induced instability. Turbulence arises in the late stage of the instability evolution as a

Effects of surface tension on immiscible Rayleigh-Taylor turbulence.

We present phenomenology describing the internal structure of a turbulent zone, produced as the result of the push of a heavy fluid into a light one, for the case of immiscible fluids. One finds that

Heat transfer in laminar Couette flow laden with rigid spherical particles

We study heat transfer in plane Couette flow laden with rigid spherical particles by means of direct numerical simulations. In the simulations we use a direct-forcing immersed boundary method to

Rayleigh–Taylor instability of immiscible fluids in porous media

The time development of an interface separating two immiscible fluids of different densities in heterogeneous two-dimensional porous media is studied. The governing equations are simplified with the

Rotating Rayleigh-Taylor turbulence

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,

Laminar, turbulent, and inertial shear-thickening regimes in channel flow of neutrally buoyant particle suspensions.

The aim of this Letter is to characterize the flow regimes of suspensions of finite-size rigid particles in a viscous fluid at finite inertia. We explore the system behavior as a function of the

International Journal of Heat and Fluid Flow

A review of recent advances in the study of high Reynolds number turbulent boundary layers is given. The emergent regime of very large-scale structures in the logarithmic region and their subsequent

Polymer heat transport enhancement in thermal convection: the case of Rayleigh-Taylor turbulence.

Numerical simulations of complete viscoelastic models provide clear evidence that the heat transport is enhanced up to 50% with respect to the Newtonian case, accompanied by a speed-up of the mixing layer growth.
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