Direct numerical simulations of heat transfer in fluidized beds of spherical particles.

Controlling heat and mass transfer in particulate suspensions has many important applications such as packed and fluidized bed reactors and industrial dryers. In this work, we study the effect of particle volume fraction and of the Grashof number (Gr) on the heat and mass transfer within a suspension of rigid spherical particles in a vertical box, using the immersed boundary method (IBM) to account for the solid-fluid interactions and a volume of fluid (VoF) method to resolve the temperature equation both inside and outside the particles.

Different Grashof numbers 0, 10000 and 40000 are simulated for particle volume fractions 1, 5 and 10% where a cold flow and hot particles with density ratio of 1.02 are introduced at the bottom of the computational domain. The average particle velocity and temperature are monitored, aiming to maximise the mass transfer while the particles are efficiently cooled down during their rise to the top of the box. Our results indicate that increasing the Grashof number increases the average particle velocity for the large volume fractions while its effect on the average temperature is almost negligible. Detailed statistics of the fluid and particle phase will be presented at the conference.