Aeroelastic analysis of straight-bladed vertical axis wind turbine blade

Abstract

To prevent flutter phenomena in a wind turbine, minimize vibration and increase the blades' life, a systematic analysis is required to investigate the effects between the cyclic aerodynamic loads and the structural performance of the turbine. A dynamic analysis of a straight-bladed vertical axis wind turbine (SB-VAWT) blade is investigated in this paper, and a simplified approach for the energy equations of an Eulerian beam subjected to twist and transverse bending deflections is introduced. The aerodynamic loads are estimated using the double multiple stream tube models. They are introduced into the dynamic model in the aeroelastic coupling, where the structural displacements are fed back to update the aerodynamic loads by utilizing the average acceleration method for the numerical integration of the equations. Reduced order modeling is then imposed based on the first modes of vibration. It is found that the structural displacement has little effect on the aerodynamic loads, and SBVAWTs experience higher transverse displacements compared with those in curved-blade VAWTs.