Experimental and numerical study of a three-blade horizontal turbine in a wind tunnel

Abstract

Electricity generation from renewable sources is essential for sustainable development and is particularly critical in regions affected by energy poverty. In this context, micro-scale wind turbines offer a viable alternative for electrifying isolated rural communities. This study evaluates, experimentally and numerically, the performance of a three-bladed horizontal-axis wind turbine designed to operate under controlled conditions in a wind tunnel. The turbine was fabricated by 3D printing and tested in the wind tunnel of the Autonomous Metropolitan University–Azcapotzalco, Mexico. Steady-state numerical simulations were performed in ANSYS Fluent using the k-ω SST turbulence model. The computational domain was discretized with polyhedral and hexahedral elements under Multiple Reference Frame (MRF) rotational conditions. A mesh-independence analysis based on the numerical torque was conducted, resulting in an optimal mesh of 2,191,718 elements. The numerical model was subsequently validated against experimental data, showing an average torque deviation of 9.27%. Flow visualization through streamlines and velocity-magnitude contours revealed unwanted vortices in the tail-vane region, which induced flow instability and mechanical vibrations in the current design. These effects should be mitigated in future design improvements. The turbine efficiency curve was obtained from electrical power measurements under different resistive loads, adjusted via a light-bulb resistance board, at a wind-tunnel speed of 18.19 m/s. The maximum efficiency achieved was 24%, corresponding to a generated power of 15.2 W at a rotational turbine speed of 3224 RPM. The results validate the proposed CFD model and provide a solid basis for future design optimization of micro-scale wind power systems for rural applications.