The most effective way to decrease the cost of energy of wind turbines is to increase the rotor diameter. Therefore, this calls for the need of aerodynamic research on large wind turbines. This thesis project will tackle the topics addressed by the IEA Wind Task 47 which is focused on the aerodynamic analysis and comparison of the newly proposed IEA 15-MW reference wind turbine using varying fidelity tools. Therefore, the main goal of this work is to analyze whether a low-fidelity approach is still feasible for aerodynamic analysis in comparison with a high-fidelity approach. It was found that there are quantitative differences between the different fidelity methods but also qualitative similarities. It can be concluded that the low-fidelity methods are relatively less suitable for a large turbine design, especially for high TSR values, which should be confirmed by further research including different fidelity tools and turbines.