Evaluation of the Effect of Spar Cap Fiber Angle of Bending–Torsion Coupled Blades on the Aero-Structural Performance of Wind Turbines

Abstract

This paper presents a comprehensive study of the evaluation of the effect of spar cap fiber orientation angle of composite blades with induced bending–torsion coupling (IBTC) on the aero-structural performance wind turbines. Aero-structural performance of wind turbines with IBTC blades is evaluated with the fatigue load mitigation in the whole wind turbine system, tower clearances, peak stresses in the blades, and power generation of wind turbines. For this purpose, a full E-glass/epoxy reference blade has been designed, following the inverse design methodology for a 5-MW wind turbine. An E-glass/epoxy blade with IBTC and novel, hybrid E-glass/carbon/epoxy blades with IBTC have been designed and aeroelastic time-marching multibody simulations of the 5-MW turbine systems, with the reference blade and the blades with IBTC, have been carried out using six different randomly generated turbulent wind profiles. Fatigue-equivalent loads (FELs) in the wind turbine have been determined as an average of the results obtained from the time response of six different simulations. The results reveal that certain hybrid blade designs with IBTC are more effective in fatigue load mitigation than the E-glass–epoxy blade with IBTC, and besides the fiber orientation angle, sectional properties of hybrid blades must be adjusted accordingly using proper number of carbon/epoxy layers in the sections of the blade with IBTC, in order to simultaneously reduce generator power losses and the FEL.

Time Domain Nonlinear Dynamic Response Analysis of Offshore Wind Turbines on Gravity Base Foundation under Wind and Wave Loads

“…In addition, to achieve higher accuracy, the cross-sectional inhomogeneity of the tower is considered here by setting different diameters and thicknesses of the beam segments. It should be noted that the rotor nacelle assembly (RNA, includes the rotor, nacelle and blades) may also affect the performance of the wind turbine [29,30]. Considering the nonlinear interaction between GBF and the soil and analyzing the dynamic response of the OWTs under wind and wave loads are the main focuses of this study.…”

“…Moreover, another one of the key factors affecting the natural frequency of the OWT structure is the force acting on the structure, which will determine the degree of nonlinear magnitude of the soil-structure dynamic interaction. Some research has focused on the interactions between the fluid and structure [29,30], including the effect of wind force, dynamic pressure and bending moment on the structures. Some research has focused on the structural design of the foundation when considering the dynamic response of the OWT under the dynamic loading.…”

Classical flutter analysis of composite wind turbine blades including compressibility

“…To study the flutter characteristics of the composite blade, a realistic baseline wind turbine blade is designed. Inverse design of the baseline wind turbine blade is based on the previous work of authors, 22 which also gives material properties of the Glass Fiber Reinforced Plastic (GFRP) material used in the full composite blade structure whose stiffness mass properties match the 5‐MW blade of NREL 23 approximately. The schematic description of blade sections with distinct airfoil profiles is shown in Figure 1.…”

Structural Performance of 14m HAWT blade through CFD

“…The results show that specific hybrid blade designs with IBTC are more active in mitigating fatigue loads compared to the composite blade with E-glass/epoxy with IBTC. Moreover, the orientation angle of fiber and sectional properties of hybrid blades must be calibrated accordingly utilizing multiple layers of carbon/epoxy within the sections of the blade with IBTC to minimize losses of generator power and FEL [13].…”