[Benfa]

I am trying to simulate the pneumatic transport of solids in 90-Degree pipe bend. The mass fraction of the solids is about 0.99 and the including air about 0.01. We are interested in the simulation of the sedimentation process in dependece of the bulk mass flow at the outlet. Because of the high volumetric fraction of the solid phase (0.63) we need to use a euler-euler description. to simulate the sedimentation we need to switch to the inhomogeneous model with the Gidaspow drag law. If we include gravity and especially the "kinetic model" for the dispersed phase we get high instability while solving. At the moment we are thinking about an alternative approach to modell the sedimentation process. Does anybody have an idea about an alternative?