[Timur]

Dear all,

I have a little bit tricky question and will be happy if any of you knows the solution.

I have a 2D pipe in which I simulate particle plug propagation using Eulerian granular model. Basically, the particles are transported at almost packed conditions (volume fraction is always around 0.6). So, due to this fact, the viscosity at the wall in the region with particles is very high and the velocity is small.

I use k-e model for turbulence with EWT. The pipe is 3.2 cm. When I mesh the pipe, I mesh it like for a single phase flow for y+=30. I am doing so because I read that at this y+ the k-e model gives better solution. But due to the fact that the viscosity at the wall in the region with particles is very high and the velocity is small, y+ for the particle is around 0.5-1. If I calculate the first layer thickness for particle velocity and viscosity, it has a value higher than the diameter which, of course, does not make any sense.

So, my question is - do I need to take into account the y+ for particles? Can k-e model work well when I have this y+ for the particle region? or I can simply consider that y+ is OK for the continuum phase and carry on with my simulation?

I would really appreciate any help!

Kind regards,
Timur