Experimental investigation of solidity and other characteristics on dual vertical axis wind turbines in an urban environment

In an urban environment, dual vertical axis wind turbines (VAWTs) are expected to demonstrate more advantage than horizontal axis wind turbine. For VAWT, solidity is one of the most important characteristics, while it has not been well studied. In this study, to investigate the effect of rotor solidity and other characteristics on the power output of counter-rotating dual VAWTs at different rotor centre spacings in a low turbulence intensity condition, twelve wind tunnel experiments for dual VAWTs and six wind tunnel experiments for an isolated VAWT were conducted. The results show that the effect of the dual VAWTs configuration on the VAWT power output is small compared with isolated VAWT under low wind speeds in an urban environment, but the effect exhibits a slight improvement with an increase in rotor solidity. As rotor solidity decreases, the sensitivity of the effect on rotor centre spacing increases. The effect of skewed flow on the power output of dual VAWTs are also well discussed. Furthermore, dual-VAWT systems are studied under real urban environment of a number of major cities such as Guangzhou, London, and Copenhagen. Potentials in different heights are compared with different configurations based on the city planning of those major cities.

Automated summary

This study investigated the advantages of dual vertical axis wind turbines over horizontal axis wind turbines in an urban environment, as well as the impact of solidity on the power output of counter-rotating dual VAWTs. Wind tunnel experiments were conducted to examine the effect of rotor solidity and other characteristics on power output. Results showed that changes in solidity had an impact on power output, indicating sensitivity to rotor center spacing. Additionally, the influence of skewed flow on power output of dual VAWTs was discussed, along with a comparison of potential configurations in major cities like Guangzhou, London, and Copenhagen.