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Proton exchange membrane (PEM) fuel cells serve a crucial role in the US decarbonization roadmap. However, water management challenges, such as liquid water accumulation in flow channels, can hinder their long-term performance. Accurately predicting the two-phase flow pressure drop is crucial to identify the extent of water accumulation on fuel cell performance. This study focuses on evaluating the liquid-gas two-phase flow pressure drop components in the flow channels of PEM fuel cells, considering different water transport mechanisms. The three components subject to study were the frictional, accelerational, and gravitational pressure gradients. The models considered in this transport phenomena incorporate electro-osmotic drag and back diffusion. The analysis also considers water evaporation and inlet reactant humidity as factors influencing water transport and pressure drop. The results provide insights into the significance of the different pressure drop components in this two-phase flow system. For the conditions considered in this study the accelerational and gravitational pressure gradients are less than 0.015% and 1.5% of the frictional pressure gradient, respectively. This study addresses a gap in the literature by documenting and validating the negligible effects of accelerational and gravitational pressure drops in two-phase flow within PEM fuel cells. These findings insights contribute to more accurate modeling and optimization of PEM fuel cell performance in practical applications. [ABSTRACT FROM AUTHOR]