Flutter analysis of wind turbine blade with carbon nanotube reinforced vinyl ester

Abstract

The aerodynamic loads of the wind cause the structure to vibrate and may result in structural failure, especially when the vibration reaches maximum beyond the structure's natural frequency. Wind turbine blades produced nowadays are large in scale, and fluttering will cause catastrophic failures in wind turbines. This research studies the flutter analysis of wind turbine blades which are made of carbon nanotube reinforced composites. Carbon nanotubes have proven to possess better material properties than carbon fibers in past researches. Hence, this research investigated the effect of carbon nanotube reinforced composites on the flutter behaviour of wind turbine blades (WindPACT 1.5 MW) under different wind speeds. The simulation method used in this research is a one-way coupling of results obtained via ANSYS Fluent and Mechanical simulations in Workbench. The material composite layup of the blade is changed from carbon fiberglass triaxial fabric to carbon nanotube reinforced vinyl ester. The pressure distributions on the blade surface at each operating wind speed were generated. FEA results such as modal shape, modal frequency, and maximum deflection were obtained. The relationship between operating wind speed and the maximum deflection on turbine blades with different reinforcement materials was determined. Results show that the wind speed that causes the largest deflection on wind turbine blades is 8 m/s. The most significant deflection of the wind turbine blade at 8 m/s is 0.6205 m and 0.65389 m with triaxial fabric reinforcement and carbon nanotube/vinyl ester composite reinforcement, respectively. The carbon fiberglass triaxial fabric is determined to be the better reinforcement for the wind turbine blade, which produced a slightly smaller deflection compared to that of carbon nanotube reinforced vinyl ester.