[Hamedhoorijani]

Hello everyone.
I'm doing a simulation of a gas-solid fluidized bed using twoPhaseEulerFoam of OpenFOAM. I built my simulation case based on the fluidized bed tutorial of the OpenFOAM. Now I have a problem with the case that I don't have the exact values of the alphaMax and alphaMinFriction from the experiments, but I know based on the literature and particles size it should be somewhere between 0.58-0.62.
For the alphaMinFriction I don't know its relation with the characteristics of the particles but I know almost everyone considers a 0.5 value for this parameter. ( If anyone has a clue about the relation of its value with the characteristics of the particle I would like to know.)
For some reason, if I set the value of the alphaMax at 0.95 the pressure drop and the value of the minimum fluidization velocity obtained are right but if I set it to 0.6, I get an increasing trend for the pressure drop with increasing the inlet gas velocity.

I'll appreciate it if anyone could guide me on how to fix this problem. for your consideration, I attach my case to this post.
Thanks alot