Cyclones are used as separation devices to remove solid particles from a gas or a liquid. The cyclone shown in the animation below is a typical high-efficiency cyclone design of Stairmand with a diameter of 0.205 m. Incompressible flow with a density of air of 1.225 kg/m3 and a viscosity of 1.7894e-05 kg/m-s was assumed. The volumetric flow rate through the cyclone was 0.08 m3/s, resulting in an average residence time of 0.25 s. The simulation was performed using the Fluent 5, unstructured mesh CFD solver. For this LES simulation a fine grid of approximately 640,000 hexahedral cells was constructed. The simulation was started with a steady state RSM solution as an initial condition. A period of 0.5 s, corresponding to two residence times, was simulated using a time step of 5E-5 s. The animation shown here shows the precessing of the vortex for a real time of 23 ms only. The vortex and the walls of the cyclone are colored by vorticity magnitude. The animation is 1 MB in size and may take a while to download.
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