Newsletter  2021.1  Index

Theme : "Mechanical Engineering Congress, 2020 Japan (MECJ-20)” Preface Masaaki MOTOZAWA, Hideo MORI Pending Issues in Large-Eddy Simulation of Turbulent Flows Takeo KAJISHIMA (Osaka University) Unsteady Flows in Turbomachines (What We Should Know and How We Can Apply to Designing) Ken-ichi FUNAZAKI (Iwate University) Modeling of a Two-Phase Flow Simulation with the Evaporation of the Gas Diffusion Layer in a Polymer Electrolyte Fuel Cell Ryuya NAGAYAMA, Satoshi SAKAIDA, Kotaro TANAKA, Mitsuru KONNO (Ibaraki University) Statistical Mechanical Analysis of Nanoparticle Behavior for Measurement of Flow Velocity Distribution in Nanochannels by Particle Tracking Velocimetry Minori TANAKA (Keio University), Itsuo HANASAKI (Tokyo University of Agriculture and Technology), Yutaka KAZOE (Keio University) Memorandum Record of the 2020 JSME Annual Meeting -as a committee member of the web conference- Yasumasa ITO (Nagoya University)

 

Modeling of a Two-Phase Flow Simulation with the Evaporation of the Gas Diffusion Layer in a Polymer Electrolyte Fuel Cell

Ryuya NAGAYAMA Ibaraki University	Satoshi SAKAIDA Ibaraki University	Kotaro TANAKA Ibaraki University	Mitsuru KONNO Ibaraki University

Abstract

Polymer electrolyte fuel cells (PEFCs) are clean power sources that generate electric energy by the reaction of hydrogen and oxygen. Because the PEFC has good characteristics such as high efficiency, harmless emissions, and quick start up, the PEFC has attractive attention as the next generation power source for vehicles. However, to make the PEFC commercially competitive in the market, it is an important issue to achieve the high current density operation. For the high current density operation, the optimization of the water transport with phase change in the cell with complicated structure is necessary. In this study, the lattice Boltzmann method (LBM) which can simulate the water and vapor transport in the cell was developed. We used a free energy-based LBM for two-phase flow with a large density ratio, and the source term for phase change was added to the Cahn-Hilliard equation in this LBM model. In addition, the convection-diffusion equation was also added to simulate the vapor transport. To verify the developed LBM model, the water flow with evaporation in a two-dimensional porous media similar with the gas diffusion layer in the PEFC was investigated. The experiment was carried out in the thermostatic chamber set at 70℃ which is the typical operating temperature in the PEFC. The simulation result of water behavior in the porous medium showed the good agreement with the experimental result. This result suggests that the developed model can simulate the water transport with evaporation in the gas diffusion layer of the PEFC.

Key words

Lattice Boltzmann Method, Polymer Electrolyte Fuel Cell, Two-Phase Simulation, Evaporation

Figures

Fig.1 Schematic diagram of polymer electrolyte fuel cell.

(a) Porous area imitating GDL	(b) Overall view of the experimental equipment
Fig.2 Porous area imitating GDL.

(a) Simulation

(b) Experiment
Fig.3 Comparison of water flow in a two-dimensional porous structure

Fig.4 Saturation of complex water flow in porous area