I use Discrete Phase Model simulate solid and liquid flow in 3D bend . My tube diameter is 5 cm . and my particle diameter is 1cm . My particle load is big ,I expect fluid field will be changed becase of particles. But I found fluid is effectd by particle is small. I use interation with continuous phase and set 50. I set under-relation factors=0.1,or 0.01 or 0.001 I want to get good stable result . But result is not stable , Particle escape time is not the same when set different under-relation factors amd different frequency in interation with fluid . Residual plot is fluctuant. if anyone have some experience do this job? Can anyone help me? Thanks!

Hi olivia,

I think that your case is a little bit out of the valid use of a DPM models : this kind of model is basing on the particle Source in Cell model which is only suitable for small particles and a small load (ie <10% in volume). I think thats why you obtain some strange results. Nevertheless you shouldn't use such small under relaxation factors because it will weak the coupling of your Lagrangian equations with eulerian phase so it is normal that it will have an influence on the solution.

You should look for another approach such Eulerian granular model or try to write your own code.