JREE: Vol. 5, No. 2, (Spring 2018) 10-21 Research Article Journal of Renewable Energy and Environment Journal Homepage: www.jree.ir Numerical Study of Curved-Shape Channel Effect on Performance and Distribution of Species in a Proton-Exchange Membrane Fuel Cell: Novel Structure Tuhid Pashaee Golmarz, Sajad Rezazadeh * , Narmin Bagherzadeh Department of Mechanical Engineering, Urmia University of Technology, Urmia, Iran. PAPER INFO Paper history: Received 15 December 2018 Accepted in revised form 20 March 2019 Keywords: PEM Fuel Cell Flow Channel Shape Mass Transport Performance ABSTRACT In this paper, a three-dimensional, single-phase proton-exchange membrane fuel cell (PEMFC) is studied numerically. Finite volume method was used for solving the governing equations and, consequently, the numerical results were validated by comparing them with experimental data, which showed good agreement. The main objective of this work is to investigate the effect of a novel gas channel shape- by applying sinusoidal gas channel- on the cell performance and mass transport phenomena. Some parameters such as oxygen consumption, water production, protonic conductivity, and temperature distribution for two cell voltages were studied, and the results were compared with respect to conventional and new models. The results indicated that the new novel model showed better performance than the conventional model, especially at low cell voltages, causing an increase in oxygen consumption and water production. Therefore, based on a number of investigated relations, a higher rate of current density was obtained, thus enhancing the fuel cell performance. This is because the incoming species path to the gas channels in the new model becomes longer. Therefore, the diffusion of the species toward the electrochemical reaction area increased. 1. INTRODUCTION 1 Fuel cells are devices that electrochemically convert the chemical energy of gaseous or liquid reactants into electrical energy. In a battery, the reactants are prevented from chemical reaction by separating them with an electrolyte, which is in contact with electro-catalytically active porous electrode structures. Apart from effectively separating the fuel and air, the electrolyte mediates the electrochemical reactions taking place at the electrodes by conducting a specific ion at very high rates during the operation of the fuel cell. In the simplest case of a fuel cell, a proton or oxide ion current is driven through the electrolyte and parts of the heterogeneous electrode structures. This type operates with hydrogen (fuel) and oxygen (air) as reacting gases [1]. Many researchers concentrated on different aspects of the fuel cell. Bernardi and Verbrugge [2, 3] studied an isothermal model that provides precious information about the physics of the electrochemical reactions and transport phenomenon in a fuel cell. Fuller and Newman [4] published a model of the membrane electrode assembly (MEA), which is based on concentration solution theory for the membrane and accounts for thermal effects. Nguyen and White [5] investigated an isothermal model. They focused on the effect of electro osmosis drag force on water transport through membrane and studied heat transfer from the solid phase to the gas phase. Dutta et al. suggested the first 3D for PEMFC [6]. Berning et al. developed steady-state, 3-D, non-isothermal models to predict PEMFC behavior [7]. Yang et al. [8] improved the performance of PEMFC. In recent years, modern numerical methods have been used to investigate the performance improvement of PEMFC. Akbari *Corresponding Author’s Email: sor.mems@gmail.com (S. Rezazadeh) et al. [9] used lattice Boltzmann method to indicate the water droplet dynamic behavior. It is necessary to understand these parameters and their effects on cell performance. Carral et al. [10] applied a finite element technique to simulate PEMFC stack. Ahmadi et al. [11] numerically and experimentally studied a PEM fuel cell. Their results indicated that the proficiency of cell was enhanced by increasing the operating pressure. They also investigated GDL geometrical configuration effect on PEM fuel cell performance. The results showed a noticeable increase in current density at the similar cell voltages, compared with the base model. Rezazadeh et al. [12] developed a three-dimensional and single-phase CFD model of a PEMFC with both gas distribution flow channels and the Membrane Electrode Assembly (MEA). They studied operating pressure effect in their paper. In addition, the effect of Gas Diffusion Layers (GDLs) geometrical configuration on cell performance showed that the observed model, with prominent GDLs, enhanced the cell performance, compared with the conventional model. While research and innovation in the field of fuel cells have been conducted, these systems and their applications are still extremely complex and expensive and are not proper for commercial use. Important aims of recent developments are concentrated on the cost reduction and large volume manufacturing of the catalyst layers, membranes, and bipolar plates. The present work is a 3-D numerical study of novel-curved- channel effect on the performance and species distribution in a PEM fuel cell. Some important parameters such as species mass fractions, cell temperature, anode, and cathode overpotential were shown and compared by a simple model in more detail.