24.5.1 Additional Guidelines for Eulerian Multiphase Simulations

Once you have determined that the Eulerian multiphase model is appropriate for your problem (as described in this section in the separate Theory Guide), you should consider the computational effort required to solve your multiphase problem. The required computational effort depends strongly on the number of transport equations being solved and the degree of coupling. For the Eulerian multiphase model, which has a large number of highly coupled transport equations, computational expense will be high. Before setting up your problem, try to reduce the problem statement to the simplest form possible.

Instead of trying to solve your multiphase flow in all of its complexity on your first solution attempt, you can start with simple approximations and work your way up to the final form of the problem definition. Some suggestions for simplifying a multiphase flow problem are listed below:

• Use a hexahedral or quadrilateral mesh (instead of a tetrahedral or triangular mesh).

• Reduce the number of phases.

You may find that even a very simple approximation will provide you with useful information about your problem.

See Section  24.7.5 for more solution strategies for Eulerian multiphase calculations.