Date of Award

Fall 2021

Publication Type

Thesis

Degree Name

M.A.Sc.

Department

Mechanical, Automotive, and Materials Engineering

Keywords

Biomimetic flow field, Dynamic contact angle, Flow field design, Fuel cell, PEMFC, Volume of Fluid method

Supervisor

B. Zhou

Supervisor

N. Eaves

Rights

info:eu-repo/semantics/openAccess

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Abstract

The performance and durability of proton exchange membrane fuel cells (PEMFCs) are greatly influenced by their water management capability. Therefore, novel flow field designs have been developing by researchers for the improvement of PEMFCs. Among those designs, novel biomimetic designs or so-called nature-inspired designs have captured special attention from researchers due to their capability of distributing fluids effectively with their prominent characteristics such as low pressure drops and efficient fluid distribution. This thesis presents a numerical investigation of the liquid water transport in PEMFC cathode with various biomimetic flow field designs. It includes a symmetrical biomimetic flow field design based on Murray’s Law, a leaf-like flow field design, and a leaf-like biomimetic flow field design based on Murray’s Law. In the studies, the volume of fluid (VOF) method is employed in order to track the gas-liquid interface. Moreover, the dynamic contact angle (DCA) effects are also considered in the simulations for better predictions of water distribution using a validated DCA model. The simulation results are the predictions of the distribution of liquid water, pressure, and velocity as well as the pressure drop. From the results, the fundamental understandings of the liquid water transportation behaviors inside the simulated biomimetic flow field designs are reported. The patterns of the liquid amount changing inside the flow field and porous layer as well as the pressure drop patterns over time are similar for all three cases. For the symmetrical design based on Murray’s Law, it shows the best water management capability among the three; However, improvements could be made such as rounded corners for better fluid distribution. Furthermore, the branching in the leaf-like designs helps to promote the electrochemical reaction inside the fuel cell and distribute the reactants throughout the flow field.

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