CFD Simulation of Laminar Rotating Flow Inside a Membrane Filter Vessel
Keywords:Wall shear stress, rotating flow, membrane, dead-end filtration, CFD
In this study, computational fluid dynamics (CFD) was used to simulate a steady-state rotating flow inside a filtration system. The shape of a 3-D vessel was designed and then meshed using ANSYS design modular (DM) and workbench mesh. The laminar viscous regime was employed; it was identified using the Reynolds number formula. As a boundary layer, the zero inlet velocity and atmospheric pressure were imposed on the inlet boundary. The obtained results showed that for a rotating velocity of 50 rpm, the shear stress distribution on the membrane surface is extremely low, except for four narrow regions situated between the extremities of the impeller and the vessel wall. The pressure variation versus z axes, below the impeller, was almost constant, and it was unevenly distributed on the membrane surface, with two areas of negative pressure. The velocity values below the impeller were higher than those above. This study provides good insights that suggest designing the impeller shape under the most extreme conditions (rotating velocity, flow regime, and pressure inlet) of the membrane. The filtration process will be performed in a future study.