[yyds4092]

Hi guys,
I am currently using Fluent with DDPM and DPM to simulate particles suspending in the liquid turbulence pipe flow. The pipe diameter is 40 mm and my particles are 2mm, which is quite large. Therefore I used very coarse mesh to ensure the mesh cell is larger than particles.

I had two problems with my simulation. Firstly, as my particles are heavier than the liquid phase, particles are settling at the pipe wall. However, some of these particles get very close to the wall which is less than 1 mm (the radius of the particle), which is physically not true. I am wondering if there is any method to push the particles out of the 1mm region.

Secondly, as the DDPM model could handle dense volume fraction multiphase flows, I tried to increase particle volume fraction up to 30 vol%. However, I found particles aggregate together at the centre of the pipe (which is true in the experiment) and the aggregation makes the simulation unstable or diverge sometimes. My initial guess is that the aggregation of particles increased the local solid volume fraction which probably reaches the limitation of the DDPM and causes such issues. I am wondering if anyone has encountered similar problems before and any suggestions for these problems.

Thanks in advance!

[hossein76]

Hello, please email me
h.mrad13766@gmail.com