Transient regime effects are particularly important in fuel cells designed for vehicles. Three-dimensional modeling of a proton exchange membrane fuel cell with a serpentine channel is presented, and the response of the fuel cell to a step-change in the mass flow rates is analyzed by using the computational fluid dynamics techniques. After a validation study of the mathematical and numerical model, step increases of 20% in mass flow rates are applied to the inlet boundary conditions, and time dependent power and current density responses of the fuel cell are analyzed. Polarization curves are generated for the assessment of the fuel cell performance, and their variations in time are presented. The results show that current and power densities increase with time at low cell voltage values due to concentration losses; however, increases in power and current are negligible at high voltages.

中文翻译：

---

质子交换膜燃料电池对质量流量阶跃变化的响应

瞬态效应在为车辆设计的燃料电池中尤为重要。提出了具有蛇形通道的质子交换膜燃料电池的三维建模，并使用计算流体动力学技术分析了燃料电池对质量流量阶跃变化的响应。在对数学和数值模型进行验证研究后，将质量流量增加 20% 应用于入口边界条件，并分析燃料电池的时间相关功率和电流密度响应。生成极化曲线用于评估燃料电池性能，并呈现它们随时间的变化。结果表明，由于浓度损失，在低电池电压值下电流和功率密度随时间增加；然而，