Verification of energy minimization multiscale (EMMS) drag model by discrete element method (DEM) simulations
The EMMS drag model has been developed to cater for computational fluid dynamic (CFD) models of dilute gas-solid flow in circulating fluidized bed risers. This drag law is largely dependent on the hypothetical division of dilute flow into dense, dilute and cluster parts and empirical parameters to represent clusters. While the model has been quite successful for the prediction of riser flows, it needs further verification, critical analysis and validation.
The proposed PhD project will conduct particle scale simulations using the DEM approach, and resulting velocity profiles, volume fraction profiles, fluctuating velocities, and energy spectra will be analysed to prove the energy minimization hypothesis in dilute gas-solid flows, while various empirical correlations of cluster diameter will be verified within the EMMS framework in DEM simulations.