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Gas distribution of proton exchange membrane fuel cells (PEMFCs) is mainly decided by flow field of bipolar plate. The improper design of distributing channel, nonuniform gas flow distribution and current density distribution among different straight channels are the leading factors that could tremendously undermine the performance and life expectancy of the cell. However, there is lack of research focusing on distributing channel in straight-parallel flow field. In this work, a three-dimensional numerical model of PEMFC cathode flow field is developed with CFD method to investigate the effects of configuration type and width of the distributing channel on pressure distribution in distributing channel and on reactant flow distribution, pressure drop and concentration distribution in multiple straight channel. Effects of electrochemical reaction and formation of water on the flow distribution are taken into consideration.

Based on the basic structure and operating function of engine throttle, according to the actual structure of throttle, a 3-dimensional air transient flow is simulated to realize throttle rotated from closed position to opened position by using CFD moving mesh technology and user defined program. By applying CFD and CAA coupling method, the influence of the movement of throttle on air flow and flow-induced noise process are studied, the transient opening process is studied and analyzed. The velocity field, pressure field and the principle of flow-induced noise are analyzed under different rotational angle velocity of throttle.