Aerodynamic Optimization and Cost-Benefit Analysis of Savonius-Darrieus Hybrid Wind Turbines for Rural Mozambique

This study presents the simulation and optimization of a hybrid vertical axis wind turbine (VAWT), combining Savonius and Darrieus wind turbine configurations, tailored for low wind conditions in Mozambique, specifically in Tete Province. Advanced tools such as Fusion 360, ANSYS Fluent, QBlade, XFOIL, Xoptfoil, and Python were used for 3D modeling, CFD simulations, and aerodynamic optimization. Three NACA profiles (0018, 4415, and 63-415) were analyzed, with NACA 63-415 showing the highest lift coefficient (CL) and the most favorable lift-to-drag ratio (CL/CD). Optimization identified an ideal angle of attack of 8°, and the Darrieus rotor with four blades operating at a tip speed ratio (TSR) of 2.0 achieved a power coefficient (Cp) of approximately 0.45. The hybrid turbine demonstrated efficient performance, with the Savonius rotor providing startup torque and the Darrieus rotor ensuring sustained energy conversion. A Python-based computational model was developed to automate turbine configuration based on regional wind data. The economic analysis estimated a total construction cost of 92,700 MZN, annual maintenance of 5,400 MZN, and annual amortization of 9,270 MZN, resulting in a cumulative 15-year cost of 220,050 MZN, compared to 1,165,500 MZN for a diesel pump system. The results indicate that the hybrid turbine is a technically and economically viable solution for rural and peri-urban communities in Mozambique.