Theoretical and numerical studies on the flow multiplicity phenomenon for gas-solids two-phase flows in CFB risers

► For gas-solids two-phase flows, the solids concentration and velocity profiles in the fully-developed region are always dominated by the solids concentration and velocity profiles at the inlet of the riser. ► The solids concentration profile is closely coupled with the velocity profile. ► The velocity difference between the two phases at the inlet of the riser is one of the main factors dominating the solids accelerating-diluting process in a CFB riser.