Effect of inlet and outlet angles on the flow performance of the ferrofluidic magnetic micropump

Abstract

AbstractThe paper presents a CFD investigation of the effect of the inlet and outlet angles on the flow performance of the ferrolfuidic magnetic mircropump. The methodology employed is based on treating the overall flow path in the inlet or outlet chambers as a series connected network, and calculating the pressure loss in the inlet and outlet at various angles by subtracting the total pressure loss in the flow path from the known pressure losses in the other items in the path. CFD simulations employed in this study include first-order and second-order momentum schemes as well as simple and couple momentum schemes. The simulation shows that a gentler inlet and outlet angles reduce the inlet and outlet pressure loss coefficients, leading to a significant drop in the torque and power needed to drive the pump, and a significant improvement in its mechanical efficiency. For a pump with typical geometric and operating conditions, reducing the inlet angle from 90° to 0° causes the inlet pressure loss coefficient to drop by 80%, while a similar reduction in the outlet angle would drop the outlet pressure loss coefficient by almost 50%. This leads to a 5.4% rise in the mechanical efficiency of the pump. Further, an increased pressure loss coefficient at sharp inlet and outlet angles compromises pump’s applicability to higher pressure application as it causes the loss of magnetic coupling between the external drivers and the driven pistons.

Keywords

• Computational Fluid Dynamics (CFD)
• Ferrofluidic magnetic mircropump
• pump performance
• inlet angle
• outlet angle
• pressure drop coefficient