Parametric Analysis of Membraneless Fuel Cells

Faculty #53
Discipline: Technology & Engineering
Subcategory: STEM Research

Arturo Pacheco-Vega - California State University-Los Angeles
Co-Author(s): Hector Gomez, California State University-Los Angeles, Los Angeles, CA

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This study presents a comprehensive numerical analysis to find the current-voltage distribution in a laminar flow-based membraneless fuel cell (LFFC) system. The main objective is to study the impact that operating conditions and geometrical parameters have on the performance of LFFCs. The system has a “Y”-shaped geometry with two separate rectangular channels that merge into a single channel, with formic acid being used as fuel and oxygen saturated in sulfuric acid as the oxidant. The configuration, which serves as baseline for the study, has a channel length of 5 cm with a rectangular cross section comprised of a width of 2 mm and a height of 0.9 mm, merging at an angle of 45 degrees. Width and length of the channels, merging angle, inlet velocity, and concentration of both formic acid and oxygen are chosen as the relevant parameters. The mathematical model for the system is formulated in terms of the Navier-Stokes, Butler-Volmer and conservation of species, along with Brinkman’s equation to describe the flow absorbed by the porous electrodes and flow through channels. The equations are solved using the finite element method, and the solutions given in terms of polarization curves. The numerical results show that LFFC systems with higher fluid velocities and oxygen concentration have a positive impact on the performance, whereas fuel concentration does not have influence on it. Finally, the concentration fields indicate an inverse correlation between the diffusion process and current density.

Funder Acknowledgement(s): NSF HRD-1547723

Faculty Advisor: None Listed,