Aero-acoustics noise evaluation of H-rotor Darrieus wind turbines

• No detailed information available describing other aerodynamic noise associated with VAWTs.
• S-1046 is the best airfoil from the noise point of view due to less aerodynamic noise generation.
• Increasing the tip speed ratio increases the noise generated form Darrieus wind turbine.
• Decreasing of the solidity reduces the noise emission from the Darrieus turbine by rate 7.6 dB.
• This work is unique in noise emissions field especially for Darrieus wind turbine.

The problems aided with wind turbine noise have been one of the more studied environmental influence areas in wind energy engineering. Noise levels can be measured, but, similar to other environmental attentions, the public's perception of the noise impact of wind turbines is in part a subjective determination. The author investigated in this work the aerodynamic acoustics of one type of the VAWT (vertical axis wind turbine) which called Darrieus turbine. Darrieus turbine is suitable to be established within the densely populated city area. Therefore, the noise item is very important to investigate. In this work, Darrieus rotor has been studied numerically and aerodynamically to obtain the generated noise from blades. This work offers a method based on the FW–H (Ffowcs Williams and Hawkings) equations and its integral solutions. Time-accurate solutions can be obtained from URANS (unsteady Reynolds-averaged Navier–Stokes) equations. Blade shape, tip speed ratio and solidity effects have been studied in this work. The results indicated that the higher solidity and higher tip speed ratio rotors are more noisy than the normal turbines.