Comparison of transient and quasi-steady aeroelastic analysis of wind turbine blade in steady wind conditions

Abstract With the increasing size of wind turbine blade, the aeroelastic analysis becomes an essential step in the blade design process. The scope of this paper is to investigate the static aeroelastic effects between the fluid–structure interaction and improve the blade performances. First, the rigid and flexible blades are used to analyze the effects of static aeroelasticity on the blade aerodynamic and structural performances through a blade element momentum model coupled with 3D finite element analysis model. Based on this, a multi-objective aerodynamic and structural optimization method is proposed aiming at increasing the annual energy production and reducing blade mass, key parameters of the blade are employed as design variables, and various design requirements including strain, deflection, vibration and buckling limits are considered as constraints. Finally, a commercial 1.5 MW wind turbine blade is applied as a case study, and the optimization results show great improvements for the aerodynamic and structural performances of the blade.

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Dynamic and Aeroelastic Analyses of a Wind Turbine Blade Modeled as a Thin-Walled Composite Beam

Volume 6B: Energy ◽

10.1115/imece2014-38679 ◽

2014 ◽

Cited By ~ 1

Author(s):

Serhat Yilmaz ◽

Seher Eken ◽

Metin O. Kaya

Keyword(s):

Wind Turbine ◽

Turbine Blade ◽

Transverse Shear ◽

Natural Frequencies ◽

Equations Of Motion ◽

Wind Turbine Blade ◽

Mode Shapes ◽

Box Beam ◽

Aeroelastic Analysis ◽

Thin Walled

In this paper, dynamic and aeroelastic analysis of a wind turbine blade modeled as an anisotropic composite thin-walled box beam is carried out. The analytical formulation of the beam is derived for the flapwise bending, chordwise bending and transverse shear deformations. The derivation of both strain and kinetic energy expressions are made and the equations of motion are obtained by applying the Hamilton’s principle. The equations of motion are solved by applying the extended Galerkin method (EGM) for anti-symmetric lay-up configuration that is also referred as Circumferentially Uniform Stiffness (CUS). As a result various coupled vibration modes are exhibited. This type of beam features two sets of independent couplings: i) extension-torsion coupling, ii) flapwise/chordwise bending-flapwise/chorwise transverse shear coupling. For both cases, the natural frequencies are validated by making comparisons with the results in literature and effects of coupling, transverse shear, ply-angle orientation, and rotational speed on the natural frequencies are examined and the mode shapes of the rotating thin-walled composite beams are further obtained. Blade element momentum theory (BEMT) is utilized to model the wind turbine blade aerodynamics. After combining the structural and the aerodynamic models, the aeroelastic analysis are performed and flutter boundaries are obtained.

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