Modelling turbulent flow within a small diameter hydrocyclone

A revised approach to modelling turbulent flow in small-diameter (10–44 mm) hydrocyclones is presented and tested quantitatively against experimental measurements. Some of the limitations inherent in the existing approaches, such as the anisotropy of turbulent viscosity and the non-linear interaction between mean vorticity and mean strain rate have been overcome utilising a k—ε model coupled with equations for calculating normal components of Reynolds stresses. The model predicts correctly the behaviour of a conventional water-fed hydrocyclone of various geometries, and has also been used to examine how the flow field can be modified by the insertion of a solid rod in place of the central air core in order to sharpen the classification performance of a hydrocyclone treating particulate suspensions.