الفهرس 
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Abstract
A fuel cell is one of the key technologies for energy production from sustainable energy sources. It can produce energy efficiently, which is virtually free from GHG emissions and independent from locally existing raw materials. This electrochemical device converts chemical energy into electrical energy. One of the most promising types of the fuel cell is the direct methanol fuel cell (DMFC). The development in the last decade has enabled satisfying power limits from the DMFC, which has resulted in an aim to reduce the price and improve the durability. However, it is still facing many issues that prevent it from being used commercially. This study aims to investigate the performance of a single phase/single channel liquid (methanol diluted with water) feed DMFC. Firstly, a three-dimensional mathematical model was developed to solve the governing equations using CFD software COMSOL numerically. The model was validated through direct comparison with previous experimental data by H. Liu[1], and the CFD model was validated by direct comparison with experimental records in the laboratory located in SRTA-City. The validation results showed a good agreement with the numerical simulation at high current densities until 200 mA/cm2 The results showed that with a temperature change the performance increases as the temperature increases up to 65 ℃. If the temperature exceeds 65 ℃, the diluted methanol will start to evaporate leading to a decrease in the overall cell performance. The results indicate that the cell performance is increased by the increase of back pressure up to 8 bar and no enhancement is observed over 8 bar. Further, the effect of the geometrical shape shows that both rectangular and the half circle give the optimum cell performance with peak power density almost at 81 mW/cm2. On the other hand, the worst performance was achieved by the triangle and trapezoidal with the maximum power density acquired as 75 and 65 mW/cm2, respectively. By decreasing the methanol concentrations from reference concentration the power decreases. The performance increases by increasing the mass fraction of Oxygen.