In this paper. the model of a proton exchange membrane fuel cell (PEMFC) with single straight channel is established to investigate the effect of dimensionless size factor of baffles on PEMFC performance. The influence of dimensionless length and height of baffles is discussed. Results show that adding baffles could dramatically optimize the mass transfer in PEMFC. https://www.unitedssports.shop/product-category/ball-glove-softball-catcher-senior/