Has anybody an idea or even experience how to model the following flow problem with any CFD code: a mixture of metal powder (up to 70 mass %) and polymer melt (nonnewtonian fluid) is pressed through a channel. The target of the simulation is the detection of phase separation at special locations (e.g. corners) due to pressure conditions etc.

Thanks for any hints

Thomas L.

There are some publications of e.g. K. Hutter in Continuum Mech. Thermodyn. pointing in that direction. I have some of them in my office at the CD-Lab. for "Rechnergestützte Angewandte Thermofl.dyn" (Petroleum Inst.). I did some work about debris flows. Although these were buoyancy driven free surface flows, the tasks were similar (phase separation, inverse grading). If you are interested in a discussion, feel free to contact me.

Christian Redl

It's really challenging problem to achieve simulation of concentrated powder flow. What's your powder size? In physics,different powder size should be catalogurized into different area?

The powder particles can be assumed as spheres with an average diameter ranging from ca. 10 to 50 micrometres. As a comparison the flow channels will be in the range from 0.5 to 5 mm.

i am doing research on something close to powder flow and in my literature survey i have found tons of papers on powder flow and the like. It seems generally to be simulated using descrete particle simulations, that is to say that the interaction and energy disappation between the individual powder particles is modelled. As you can imagine you will need a huge computer to do this, and in fact no practicle flows have really been modelled on anything other that a small scale. Coulomb powder modelling may be more suitable for you but literature on this is sparce to say the least, although i have found one very usefull paper. My problem does sound a little like yours so if you drop me an e-mail then i should be able to tell you more, and failing that give you a list of some usefull literature.