Spatially-Averaged Models for Heat Transfer in Dense Gas-Solid Flows: Constitutive Relations

Description

Full-scale simulations of large-scale dense gas-solid flows, like fluidized beds, are not feasable due to computational limitations, therefore, coarse computational grids are used. These coarse grids, however, do not resolve mesoscale structures, like clusters and streamers. The influence of these mesoscale structures on the macroscopic behaviour of the gas-solid flow cannot be neglected, thus, these unresolved terms need to be modelled. We use spatial averaging to derive a model for the unresolved interphase heat transfer. The filtered heat transfer can be approximated by the resolved heat transfer corrected by the drift temperature. The drift temperature is the difference between the gas-phase temperarture and the gas-phase temperature as seen by the particles. This term stems from phase averaging. The proposed closure model for the unresolved heat transfer fits well with the predictions obtained by filtering highly resolved fine grid simulation data. Finally, a transport equation for the turbulent thermal energy is derived in order to close the drift temperature.

Period	21 May 2019
Event title	10 th International Conference on Multiphase Flow
Event type	Conference
Location	BrazilShow on map