Thermophysical Effects on the Aerodynamic Efficiency of Combined Wind Turbine Blades

Abstract This study investigates the aerodynamic performance of a combined wind turbine blade (a rotating cylinder with a fixed stabilizer) under varying air temperatures from 0°C to 20°C. Laboratory experiments were carried out to measure pressure distributions on the blade’s surface at different airflow velocities (5–15 m/s) and cylinder rotation speeds (637–1217 rpm). The analysis incorporates Bernoulli’s equation and fundamental aerodynamics, accounting for changes in air density and viscosity with temperature. Results show that as air temperature rises from 0°C to 20°C, air density drops from 1.292 to 1.204 kg/m³, leading to earlier flow separation and stronger vortex formation. Consequently, the pressure differential between the blade’s upper and lower surfaces grows, enhancing lift and improving turbine efficiency by approximately 10%–15%. A comparative experiment using a lower-density gas confirmed the strong dependence of aerodynamic characteristics on the working fluid’s thermophysical properties. These findings can inform the design and optimization of wind turbines for regions with significant temperature fluctuations, demonstrating that the combined blade concept offers improved stability and performance under variable climatic conditions.