The above equations are limited in many regards. For example, the geometry of the separator is not considered, the particles are assumed to achieve a steady state and the effect of the vortex inversion at the base of the cyclone is also ignored, all behaviours which are unlikely to be achieved in a cyclone at real operating conditions.
More complete models exist, as many authors have studied the behaviour of cyclone separators., simplified models allowing a quick calculation of the cyclone, with some limitations, have been developed for common applications in process industries. Numerical modelling using computational fluid dynamics has also been used extensively in the study of cyclonic behaviour.  A major limitation of any fluid mechanics model for cyclone separators is the inability to predict the agglomeration of fine particles with larger particles, which has a great impact on cyclone collection efficiency.