## 2 Literature Survey
### PEMFC and Various Design
The contours and the polarization curves for the flow fields have been used for comparison. The output numerical results of the models stated that the parallel flow field performance is lesser than the other two designs due to insufficient reactant distribution. They reported that the compound flow field is better for controlling and reducing flooding. However, the performance of the compound flow field was similar to that of the serpentine flow field. A volume of fluid (VOF) model which has been coupled with a one-dimensional MEA model to study the effect of low misdistribution in parallel channels of a PEMFC [14]. The results state that the slug flow patterns increase the surface water coverage in the gas diffusion layer, decreasing cell performance. The performance of the fuel cell can be improved by optimizing the flow field resistance without causing much loss of pressure in the flow. A detailed review on the application and development of stainless steel bipolar plates (BPPs) for PEMFC was performed by [15]. Various assemblies and processes required for manufacturing and optimizing the performance of these steel BPPs have been discussed. A detailed discussion about the various processes involved in stainless steel BPPs, such as laser welding, micro-stamping, rubber pad forming, and hydro-forming have taken place. They reported the effects of anti-corrosive and conducting coatings on stainless steel materials. The effects of various errors in the shape, size, and other parameters of the BPPs on the performance have also been reported. A numerical and CFD simulation to determine the optimum channel width to rib height ratio for serpentine flow fields to get the optimum performance of the fuel cell [16]. Seven different flow fields have been analyzed, and its effects on water distribution, current density, flooding, and reactant gases mass fraction were also studied numerically. Pressure, stoichiometry, and temperature effects have also been evaluated in this study [17]. The numerical analysis on the anode and the cathode gas channel of a PEMFC with rectangular-shaped obstacles in the flow field was conducted by [18]. By using a 3D CFD model, the numerical analysis of the flow field with obstacles at different operating parameters of relative humidity, stoichiometry, and temperature was studied. The authors reported that the flow field with rectangular obstacles, and the current density values are higher than ordinary flow fields. The fuel cell performance is studied by using the I-V polarization curves [19]. An effective cooling system for a PEMFC was considered by [20], the authors of which performed a numerical investigation of new and different cooling flow fields. The parameters like thermal behavior, pressure drop, and coolant flow distribution of various thermal designs have been studied. They stated an increase in the mass flow rate of the cooling field as well as a minimization of the maximum temperature difference between flow field surface. An investigation on water dynamics inside the PEMFC was performed by [21], the authors of which investigated the water content at the cathode of the PEM cell due to the dynamic behavior of liquid water. The surface coverage of the GDL by water can be greatly reduced, and this can be achieved by increasing the inter-pore distance, and decreasing the pore diameter. The three-dimensional PEMFC with different operational parameters and geometric inputs [22]. They have compared the simulated model with experimental results, and there is a good match between them. These parameters include species concentration, water content in the PEM, over-potentials, and the current densities. The effect of these factors on cell performance has also been evaluated.