Investigation of droplet motions in a PEM fuel cell channel with an extra outlet and a reservoir by the vof method

PEM Fuel Cell has become an important topic in the search of clean, renewable energy sources. It uses hydrogen as an energy carrier and it produce water and electricity. If the produced water can't be evacuated from the cell, the transformation across the PEM could be blocked and/or reaction area would be decreased. On the other hand, if the PEM completly dry out, its proton conductivity would be lowered. Therefore, water management with a steady evacuation must be achieved in order to work PEMFC efficiently. One of the ways of achieving such water management is designing flow channels accordingly. In this work the water droplet movement in a PEMFC channel with an extra outlet is investigated with CFD analysis. A water droplet in the channels with two outlets are modelled in ANSYS Fluent, varying one of the outlets pressure, droplet size or the direction of gravitational accelerations in each case. As a result,it is observed that only the stationary droplets which are close to the extra outlet is discharged in no time. Lowering the gage pressure of extra outlet is needed to discharge non-stationary droplets. In addition, little effect of the direction of gravitational acceleration is seen.