Numerical simulation analysis of particle motion behavior and key structures inside a novel cyclone separator

Abstract

This study proposes a novel cyclone separator with a conical inner core to enhance particle classification efficiency in oil and gas wellhead-recovered liquids. Particle motion and force dynamics are analyzed to optimize key structural parameters, including inlet diameter (D_i), overflow pipe diameter (D_e), insertion depth (L_e), and bottom flow pipe diameter (D_z). Numerical simulations employ the Reynolds stress turbulence model, SIMPLEC algorithm, and discrete phase model to evaluate separation performance in a gas–liquid two-phase system. Results indicate that a smaller D_i improves fine particle separation but increases turbulence; an optimal range of D_i/D_c = 0.35–0.4 is recommended. Larger D_e enhances the diversion ratio, aiding fine particle discharge (D_e/D_c = 0.25–0.35). Increased L_e facilitates fine particle overflow but induces vortices, whereas a smaller L_e stabilizes the bottom flow for larger particle separation (L_e/D_c = 0.5–0.75). A reduced D_z enhances centrifugal force and separation efficiency but may cause turbulence; an optimal D_z/D_c of 0.6–0.65 is suggested for stability. These findings provide valuable design guidelines for improving cyclone separator performance in multiphase flow applications.