Numerical investigation of fluid-structure interaction in valved piezoelectric pump by offset in solid meshes

A more accurate and comprehensive two-dimensional (2D) model of valved piezoelectric pumps is proposed using fluid-structure-electromagnetic coupling. The valve mesh offset avoids truncation in the fluid domain caused by valve collisions, offering a solution to the solid-solid collision problem within the fluid domain. The impact of offset distance, drive parameters, and structural parameters on the output flow, internal pressure, and flow field within the cavity of the valve-integrated piezoelectric pump is systematically discussed. The primary results are as follows: (1) As the offset distance decreases, the convergence of the model decreases significantly, and therefore, the offset distance should not be less than 3.0 × 10−7 m. (2) The output flow varies with driving frequency, showing a trend of increase and then decrease, with a peak value at 250 Hz. (3) As the chamber height increases, the output flow gradually increases and stabilizes at 0.5 mm, with no further increase. (4) The optimal driving frequency was 250 Hz, with a peak performance of 21.5 ml/min, demonstrating a trend of increase followed by a decrease. (5) The cantilever valve offers superior sealing performance compared to the umbrella valve and wedge valve under the same specifications, with less reflux per cycle. (6) Flow field, pressure, and stress diagrams visually demonstrate the valve motion process under the interaction between the piezoelectric actuator and the fluid. This work provides a more accurate and cost-effective solution for the design of valved piezoelectric pumps, offering important guidelines for further pump design.