SIMULATION OF 3-DIMENSIONAL FLOW IN INTERNAL MIXERS

The design of internal mixers for the rubber industry has traditionally been based on the basis of intuition rather than a knowledge of the fluid mechanics of motions in the internal mixer. In recent years, efforts have been made to numerically simulate the flow and mixing characteristics in internal mixers. The simulation effort is important for the understanding of mixing mechanisms in the internal mixer, and furthermore, to provide a basis for rational design. In this paper, we develop a new model based on cylindrical coordinate hydrodynamic lubrication theory for internal mixers. This allows full consideration of curvature in an internal mixer. Numerical techniques are used to carry out the calculations of the pressure field and flux field for various rotors described in the patent literature. This is done for a Newtonian fluid in a fully filled mixing chamber. This type of calculation is of key importance in the design of flight arrangements on internal mixer rotors.