Comments on "Flow distribution in U-type layers or stacks of planar fuel cells" by W.H. Huang, Q.S. Zhu [J. Power Sources 178 (2008) 353-362]

A comment on the article 'Flow distribution in U-type layers or stacks of planar fuel cells' by WH Huang and QS Zhu published in the Journal of Power Sources, is presented. This paper discussed the flow distribution and pressure drop in U-type layers or stacks of planar fuel cells. The model presented in the paper neglected the inertial term, retaining the friction, and obtained an analytical solution. Flow distribution and pressure drop in this type of manifold systems were some classic issues in chemical, mechanical, and civil engineering. Recently Wang obtained an analytical solution without neglecting the inertial and the frictional terms. He proved that there were three solutions rather than one solution, which further stated that neglecting of the inertial terms caused lost of two solutions with the triangular function and the exponent function.