Authors:

Gabriel Br

Date Created:

Not specified

Course Title:

Professor:

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About Paper:

In air and water filtration applications, membranes are employed to filter fluids that have been polluted by particulates. Among such filtration membranes, vibrating membranes have greater capture efficiencies, better anti-fouling qualities, and longer lifespan than static membranes. Membrane vibration is induced via the converse piezoelectric effect, a material property in which an applied voltage causes mechanical strain in the membrane. Experiments by Akshay Deolia using a polyvinylidene fluoride (PVDF) membrane in water have shown displacement amplitudes significantly greater than the piezoelectric tensor of PVDF and applied voltage suggested. Displacement was also smaller in air than in water, a denser and more viscous fluid. A COMSOL Multiphysics 6.2 model of the PVDF membrane in both water and air was employed, with acoustic-structure interactions, solid mechanics, electrostatics, and their respective couplings being considered. System damping was modeled as dielectric losses and mechanical boundary layer impedance. Eigenfrequency analysis and frequency domain studies were conducted to reproduce the observed membrane displacement amplitudes. Results are interpreted in terms of both membrane displacement amplitudes and fluid total acoustic pressure at both membrane and fluid resonant frequencies. A better understanding of where system eigenfrequencies are located, membrane eigenmodes, damping mechanisms, and displacement amplitudes was achieved. In addition, hypotheses for both the greater membrane displacement amplitude seen in water and the mechanism under which membrane flexural resonances are excited are proposed. Keywords: [no keywords provided]

Source:

Purdue University / 2024

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Co-authors:

Gabriel Br