Hydrodynamics of liquid flow in a rotating cone.

The average residence time of liquid flowing over the surface of a rotating cone was determined numerically. The development and propagation of the free surface flow was simulated using the volume of fluid (VOF) method. The numerical simulations were validated using laboratory experiments using soy-oil as a model liquid, and approximate analytical solutions of the simplified governing equations. The numerical simulations revealed the importance of the cone rotation frequencies and the minor influence of the cone angles on the residence times. Higher liquid throughputs produced smaller residence times. As expected, an increasing cone size results in proportionally higher residence times. Furthermore, it was established that even for small cones with a characteristic diameter of, e.g. less than 1m, relatively high (~1 kg/s) throughputs of liquid are possible. It appears that the combination of the decreasing layer thickness and the increasing size of the numerical grid cells with increasing radial cone coordinate hampers the numerical simulation of this system.