Computational fluid dynamics prediction of the air-core in hydrocyclones

Abstract

The air-core diameter was successfully predicted by large eddy simulation and volume of fluid models. The dynamics of the flow for 75- and 250-mm hydrocyclones was evaluated in 11 cases in which the spigot diameter, conical length, vortex finder diameter, diameter of the hydrocyclone and viscosity of the fluid were changed. FLUENT™ 6.0 code was used to compute the dynamics of the flow. The air-core profiles demonstrated the accuracy of the simulations. A reduction in the spigot increases tangential velocity and hence air-core diameter is increased. An increase in hydrocyclone diameter also increases air-core diameter, while the vortex finder or an increase in fluid viscosity inversely influences it. The vortex finder influences inversely air-core diameter. The increase in viscosity of the fluid reduces air-core diameter. The computational time required to reach the solution increases as the domain size increases. The LES model cannot be used in everyday cases to optimise hydrocyclones, but it is an outstanding tool to study new designs.

Keywords:

• hydrocyclone
• air-core
• large eddy simulation model
• volume of fluid model