Hydrodynamics of particle-free and particle-laden laminar flows in sharply bent channels

Abstract

Sharp bends alter the hydrodynamics of particle-free and particle-laden fluid flow and induce additional losses in the form of recirculation zones that can be viewed as increase in entropy of the system. Here, we use a thermodynamic relation that accounts for the dissipation rate to delineate the contribution of recirculation zones and obstruction in the fluid flow due to channel bending. Results show that secondary flow formation dominates over obstruction effects at lower Reynolds number and becomes weaker at higher Reynolds number for both particle-free and neutrally buoyant particles. However, for inertial particles, obstructive forces prevail over the dissipative forces.