Design and Performance Evaluation of a Mid-Range Airborne Wind Turbine

The focus of this study is on the aerodynamic design of a 2000-W airborne wind turbine (AWT) situated 100 m above ground level. AWTs harness higher wind speeds at higher altitudes, making them more efficient than ground-based turbines in generating power. To achieve the desired performance, numerical methods, such as blade element momentum (BEM) and computational fluid dynamics (CFD) were employed for the aerodynamic design and analysis of the AWT system. The rotor cross-section of the three-blade rotor incorporates S223 and S822 airfoils, which are derived from the conventional NREL airfoils. The diffuser section of the AWT has an elliptical curve to accommodate the maximum volume of helium gas. Through simulations using both CFD and BEM, the performance of the bare rotor was assessed, as well as the diffuser-augmented wind turbine (DAWT) under design and off-design conditions. The results demonstrated that the DAWT is capable of meeting the desired power output in all scenarios. Moreover, the findings indicated that using the diffuser enhances the rotor output power coefficient by 18% and prevents significant power loss during off-design conditions. This highlights the effectiveness of the rotor-diffuser assembly in maximizing power generation and ensuring consistent performance of the AWT system.