Effects of particle settling on Rayleigh-Bénard convection

Abstract

The effect of particles falling under gravity in a weakly turbulent Rayleigh-B´enard gas flow is studied numerically. The particle Stokes number is varied between 0.01 and 1 and their temperature is held fixed at the temperature of the cold plate, of the hot plate, or the mean between these values. Mechanical, thermal, and combined mechanical and thermal couplings between the particles and the fluid are studied separately. It is shown that the mechanical coupling plays a greater and greater role in the increase of the Nusselt number with increasing particle size. A rather unexpected result is an unusual kind of reverse one-way coupling, in the sense that the fluid is found to be strongly influenced by the particles, while the particles themselves appear to be little affected by the fluid, despite the relative smallness of the Stokes numbers. It is shown that this result derives from the very strong constraint on the fluid behavior imposed by the vanishing of the mean fluid vertical velocity over the cross sections of the cell demanded by continuity.


Autore Pugliese

Tutti gli autori

  • Oresta P , Prosperetti A.

Titolo volume/Rivista

PHYSICAL REVIEW E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS


Anno di pubblicazione

2013

ISSN

1539-3755

ISBN

Non Disponibile


Numero di citazioni Wos

Nessuna citazione

Ultimo Aggiornamento Citazioni

Non Disponibile


Numero di citazioni Scopus

1

Ultimo Aggiornamento Citazioni

2017-04-22 03:20:59


Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile