Wind tunnel and numerical performance analysis of multi-storey vertical axis wind turbines

Vertical Axis Wind Turbines (VAWTs) are becoming popular due to low capital and operating cost. Most of the research on the VAWT is related to power coefficient improvement. Self-starting wind speed performance of the VAWT is another important performance factor which helps in improving overall power performance due to the increase in overall operating period. In this study, an innovative multi-storey turbine model is proposed to improve the self-starting wind speed performance. The self-starting wind speed performances of a three-storey VAWT model is measured in wind tunnel which is further compared with the performances of the one-storey and two-storey turbines. Other performance parameters like maximum torque and power coefficients are also measured in wind tunnel and compared with Computational Fluid Dynamics (CFD) simulated model results. CFD models of all three turbines are developed using FLUENT Software which uses k-omega Shear Stress Transportation turbulence model. CFD analysis also provides detailed insight about turbine performances, viz., lift coefficients and drag coefficients, velocity distribution, and pressure distribution. This analysis brings out the advantage of three-storey VAWT which gives minimum value of self-starting wind speed of 2 m/s as compared to two-storey and one-storey turbines of 3.3 m/s and 7m/s, respectively. Further, this study brings out comparison of other performance parameters of three models. (C) 2015 AIP Publishing LLC.