Experiments for viscous flows with small fluid inertial effects have not substantiated early hypotheses of energy minimization for fluid-solid flows. For gas-solid flows, no evidence exists to suggest that flow conditions can minimize energy dissipation. Several assumptions of minimum energy dissipation in circulating fluidized beds based on the pressure drop, suspensions of neutrally buoyant bodies and non-neutrally buoyant bodies, extremum principles for particle-fluid systems, and thermodynamic aspects are presented.
Hyre, M., & Glicksman, L. (1997). Brief communication on the assumption of minimum energy dissipation in circulating fluidized beds. Chemical Engineering Science, 52(14), 2435–2438. https://doi.org/10.1016/S0009-2509(96)00508-8