Performance Evaluation of a 1 kW Variable Pitch-Straight Blade Vertical Axis Wind Turbine

Abstract

This research work represents a study of the design, analysis, and experimental study of a 1 kW variable pitch-straight blade vertical axis wind turbine (VAWT) using natural fiber reinforced composite. Wind turbine which is an emerging technology is of great interest for researchers nowadays. The VAWT was chosen for this study because of its numerous advantages over horizontal axis wind turbine (HAWT). A new concept of variable pitch was implemented by the introduction of a pitching mechanism associated with the turbine blades which helps the blade to maximize the generation of torque and power. For this purpose, the straight blade H-rotor design was chosen. The analytical calculations were performed for variable pitch and the fixed pitch blade followed by the computer aided design modeling of the rotor exhibiting the variable pitching mechanism. Computational fluid dynamics (CFD) analysis of the blade at the azimuth position of 0–360 deg was performed and the CFD results were imported into static structural module of ansys for the finite element analysis of the blade. The blade was 3D-printed at a reduced scale and tested in a wind tunnel for aerodynamic properties including lift, drag, and aerodynamic forces. A comparison was done between the analytical, software, and experimental values. Furthermore, basalt fiber which is a natural fiber was used as the material for the turbine blade and analysis was performed to obtain high strength to weight ratio of the composite material. The structure was analyzed under the damage tolerance study to determine for how long the structure can bear damage. The experimental results showed a good agreement with the analytical and numerical values. The introduction of the variable pitching mechanism resulted in an increase in the cumulative torque as compared with the fixed pitching mechanism which in turn enhanced the resulting power.