Numerical Study of Aeroelastic Behaviour of a Troposkien Shape Vertical Axis Wind Turbine

A methodology for aeroelastic analysis of Vertical Axis Wind Turbines (VAWTs) with troposkien geometry is developed. The structural dynamic equations used in this analysis represent the behaviour of a three dimensionally curved beam in terms of generalized force and generalized displacement vectors. It is demonstrated that the mixed form of the equations lends itself well to the application of mixed finite element method. The structural dynamic equations are coupled with a free vortex based aerodynamic model. The aerodynamic model represents the wake with vortex filaments that stretch, rotate and translate freely in the wake of the wind turbine. The computational aeroelastic framework is utilized to study the aeroelastic behavior of the 17-meter DOE-Sandia VAWT. The comparison of the estimated vibratory stress at the root of wind turbine with the experimental data reveals excellent agreement except at the region where dynamic stall plays a crucial role in predicting the aerodynamic forces.