Numerical Analysis of a High-Power Piezoelectric Pump using Computational Fluid Dynamics (CFD) Simulations

In recent years, piezoelectric materials have gained increasing attention for their high performance, reduced moving parts, and design flexibility. This interest has led researchers to explore their application in piezoelectric pumps, commonly known as piezopumps. These pumps leverage the inverse piezoelectric effect to generate fluid flow, offering advantages like compact size, low weight, precise control, and minimal power consumption. Explored in diverse fields such as biomedicine, robotics, aerospace, electronics, chemistry, and automotive, piezopumps excel in microfluidic systems, where miniaturization, accurate fluid transfer, high resolution, and enhanced reliability are crucial. Despite these benefits, in the field of fluid power, the conventional design of existing piezopumps, involving a piezostack driving a piston at high frequency and a pair of check valves regulating flow in and out of the pump chamber, makes them prone to cavitation. The latter phenomenon can result in damage to components, reduced efficiency, and noise generation. In light of this, this paper initiates a numerical investigation using CFD software to assess the potential for cavitation initiation in a specific piezoelectric pump developed at the University of Bath. This pump is capable of delivering a power output in the range of (10–100) W and flow rates of 1 L/min. To achieve this, reed valves are utilized as check valves, suitable for frequencies exceeding 1 kHz. The study simulates two diverse oil flow scenarios through the piezopump with fixed inlet pressure and chamber pressure, and varying inlet reed valve opening. Specifically, the focus is on visualizing the pressure drop across the inlet reed valve, a key factor in initiating cavitation. This approach allows for a comparison of different steady-state scenarios and an evaluation of potential situations that may lead to cavitation.