Abstract: In order to investigate the effects of cone angle on the flow field and separation performance of hydrocyclone， a systematical numerical study on a laboratory [?]50 mm hydrocyclone were conducted by using the RSM turbulence model， VOF and Mixture multiphase flow model by Fluent software. The flow field simulation results show that under the same operating conditions， with cone angle increasing， the air core diameter， turbulence intensity， pressure and pressure gradients are significantly increased， resulting in an increase in overall energy consumption. The tangential velocity also increases with the increase of cone angle， but the axial velocity does not change obviously. However， the LZVV gradually moves toward the wall， and the split ratio decreases subsequently. The simulation results of particle separation show that increasing the cone angle leads to an increase in the cut-size and a decrease in the separation efficiency for each size fraction. In addition， a small cone angle is likely to increase the misplacement of fine particles in underflow， while a large cone angle might enhance the entrainment of coarse particles in overflow. The results provide a reference for the selection and design of the conical structure of hydrocyclones.

Key words: Hydrocyclone, Numerical simulation, Cone angle, Flow field, Separation performance