Studies on strongly swirling flows in the full space of a volute cyclone separator

The three-dimensional (3-D) strongly swirling turbulent flows in the full space of a volute cyclone separator was measured using laser Doppler velocimetry (LDV), and was simulated using an improved Reynolds stress equation model by modifying the empirical constants in the isotropization of production and convection model (IPCM) + wall pressure-strain term of the Reynolds stress equation, incorporated into the platform of FLUENT 6.0. Predicted Reynolds stress model (RSM) velocities are more reasonable than those obtained previously. The specific features of turbulent flows in the separation space, dust hopper, annular space, and the outlet tube are different. The results show that the time-averaged tangential velocity profiles in the separation space have a typical Rankine-vortex structure. In some regions, such as the entrance, the vicinity of the top of the annular space, the inner vortex-flow region, the vicinity of the discharge port, the vicinity of the wall, the intersection part between the upward and downward flows, the turbulent intensity is very large and changes sharply; the turbulence is anisotropic in most regions, but the magnitudes of three RSM velocity components are of the same order of magnitude. The distribution of time-averaged tangential velocity is asymmetric in the annular space. The longitudinal secondary vortexes exist near the top of the dust hopper and the top of the cyclone. The distribution of time-averaged axial velocity in the exit tube is entirely different from that in the separation space. (C) 2005 American Institute of Chemical Engineers.