Cyclone: Particles Motion

Cyclone with the Motion of Particles, ANSYS Fluent CFD Simulation Training

Description

This project simulates the motion of particles within a cyclone using ANSYS Fluent, employing a one-way DPM approach to model the discrete phase. A cyclone is a device used to separate particles from a gas stream, with widespread applications across industrial processes.

The 3D geometry was built in SpaceClaim, with a computational domain measuring 101 mm in both length and width, and 363 mm in height. The domain was meshed in ICEM CFD using an unstructured grid totaling 371,350 cells.

Methodology

Several assumptions were applied to the simulation: a pressure-based solver was used, the simulation was run as unsteady, and gravitational effects were included at -9.81 m/s².

Key simulation settings included:

• Viscous model: Reynolds Stress model

• Discrete phase: Enabled with unsteady particle tracking; anthracite defined as the injected material, treated as inert, using a group injection type

• Boundary conditions: Velocity inlet at 5.9 m/s with discrete phase set to escape; pressure outlet at 0 Pa gauge pressure with discrete phase set to escape; stationary walls with discrete phase set to reflect

• Solution methods: SIMPLE pressure-velocity coupling, second-order discretization for pressure, second-order upwind for momentum, and first-order upwind for the modified turbulent viscosity

• Initialization: Hybrid method

Conclusion

The simulation captures particle motion behavior throughout the cyclone in detail. Most particles entering through the inlet exit through the lower outlet, while the air phase exits through the upper outlet — consistent with the expected separation mechanism. A small fraction of particles, however, become trapped in the upper region of the cyclone, continuing to rotate indefinitely rather than exiting through either outlet, highlighting a practical limitation in separation efficiency that can occur within real cyclone geometries.