The effect of cyclone vortex finder dimensions on the flow pattern and performance using LES

The effect of the vortex finder dimensions (both the diameter and length) on the performance and flow field pattern in nine cyclone separators has been investigated computationally using the large eddy simulation (LES). The vortex finder diameter varies from 0.3 to 0.5 times the cyclone diameter. The vortex finder length varies from 0.5 to unity times the cyclone diameter. Decreasing the vortex finder diameter by 40% results in 175% increase in the dimensionless pressure drop (Euler number) and 50% decrease in the Stokes number. Doubling the vortex finder length increases both the Euler number and the Stokes number by 25%. Decreasing the vortex finder diameter causes a gradual change in the axial velocity profile from the inverted W to the inverted V profile accompanied with 73% increase in the maximum axial velocity. The maximum tangential velocity approaches asymptotically 1.6 times the inlet velocity (25% increase) when decreasing the vortex finder diameter by 40%.

► Nine cyclone separators with different vortex-finder dimensions have been investigated with LES.
► Grid indecency has been tested using grid convergence index (GCI).
► Decreasing the vortex finder diameter by 40% increases in the Euler number by 175%.
► Doubling the vortex finder length increases the Euler and Stokes numbers by 25%.