[Vivivvvvd]

hi
During my simulation of a gas-solid fluidized bed using the Eulerian Eulerian method, I found a problem with the pressure drop.
In simulations where the inlet velocity is much less than the minimum fluidization velocity, this pressure drop is consistent with a bubbling state, but there are no bubbles in the Volume Fraction plot of the particles.
I have only selected Granular in the solid setup and not Packed Bed, should I add Packed Bed as an option?
If I should not add the Packed Bed option, what should I do to adjust the parameters of the simulation?
Thank you for your help.