Flow Simulation of Gas Cyclone Separator at High Reynolds Number Using theElliptic-Relaxation Hybrid LES/RANS (ER-HRL) Model

In this paper, we investigate Wall-Modeled Large Eddy Simulation (WMLES) in a stairmand high-efficiency cyclone separator at two Reynolds numbers i.e. Re = 33,045 - 280,000. We compute the gas flow using the elliptic relaxation hybrid RANS/LES (ER-HRL). The model employs a wall integration linear eddy viscosity RANS model for the wall-adjacent region, and switches to the LES dynamic model in the bulk flow. At the lower Reynolds number i.e. Re = 33,045, we investigate the effect of varying cone bottom opening – rendering three different cyclone configurations – on cyclone performance. Flow statistics are reported at several locations across the cyclone axis where both mean and RMS values are observed. For high Reynolds number i.e. Re = 280,000, results are compared against LES and experimental databases from literature. Model predictions of mean flow are in good agreement with reference data, while higher-order moments i.e. RMS values are not very well predicted by the model despite following the same trend of experimental data. Results are in a global good agreement with LES and experimental data at a fraction of well-resolved LES CPU cost. This analysis will serve as a good basis for further investigation of cyclone grade efficiency using Lagrangian particle tracking.