Sand-Water flow
 

Hello Everyone,

Recently, I have tried to simulate a two phase solid-liquid flow in a horizontal pipe of 10m length. I used the Eulerian Model in conjunction with the standard
κ-ε Turbulence model-mixture model. Furthermore, i treat the flow of solids as granular and have used gidaspow model for drag effects. I use a time step of 0.001 and 5000 time steps (total 5sec of flow).

The problem is that when the simulation is completed i receive a higher value of sand volume fraction inside the pipe than the initial value i used. For example my initial sand volume fraction is 0.000538 and the values i receive are 2 orders of magnitude higher, e.g. 0.02-0.03. I think that there is a linearisation problem of the granular kinetic theory models used but i dont know exactly why is this happening..

Could you please help me???
Thank you in advance