Numerical Study on Aerodynamic Performance of Different Forms of Adaptive Blades for Vertical Axis Wind Turbines

Abstract

The wind energy exploitation technique has been developed very quickly in recent years. The vertical axis wind turbine is a hot research domain due to several advantages: low noise, flexible for installation, ease of maintenance, great safety and credibility, etc. The aerodynamic performances of different forms of airfoils including an active deformation airfoil and a fluid-solid coupling passive airfoil with two-dimensional (2D) and three-dimensional (3D) cases have been investigated numerically in this paper. Firstly, the aerodynamic performances of the airfoils with the maximum deformation amplitudes of their cambers which are 3%, 5% and 7% of the chord length have been discussed, respectively, with the angles of attack in the range of 0° and 20°. Secondly, for the angle of attack set at 18°, the two-way fluid-solid coupling simulations with the Young’s Modulus of 1 Mpa and 2 Mpa have also been investigated. Results show that: (1) for the pseudo 3D and real 3D single active deformation airfoil cases, the lift coefficients increase as the maximum deformation amplitudes augment from 3% to 7% of the chord length at the same angle of attack. With the same maximum deformation amplitude, when the angles of attack increase from 0° to 20°, the lift coefficients which increase firstly and then decrease are bigger than that of the original NACA0012 airfoil. When the maximum deformation amplitude of the pseudo 3D airfoil reaches 5% of the chord length, a relatively good aerodynamic performance with better inhibition effect of vortex generation can be obtained. The 3D vortex distribution demonstrates that the deformable airfoil has a better vortex generation controlling effect at the middle cross-section along the spanwise direction than the non-deformable airfoil. (2) From the aspect of fluid-solid coupling, the lift increases and the drag decreases so that the lift to drag ratio has a big improvement when the Young’s Modulus is equal to 1Mpa and 2Mpa. The deformable airfoil can inhibit the generation and the shedding of the surface vortex when the fluid-solid coupling effect is considered.

Recent Development in the Design of Wind Deflectors for Vertical Axis Wind Turbine: A Review

“…In recent years, various techniques for deflector installation and modified designs have been reported [22]. Many of these designs have been reported with validated simulations and have contributed to turbine blade wind flow improvements.…”

Optimum design of morphing flaps for improving horizontal axis wind turbine performance

“…In their study, using active hinged flaps, there was double the fatigue reduction potential compared with the original blade, while the increment in AEP was approximately 1% 18 . It has also been shown that in vertical axis wind turbines, the use of morphing blades increases the pressure coefficient and delays the separation of the flow 19,20 . McWilliam et al used a morphing flap on a constant length in their aeroelastic optimization of the 10‐MW wind turbine blade and investigated its effect on each speed compared with the baseline blade.…”

“…18 It has also been shown that in vertical axis wind turbines, the use of morphing blades increases the pressure coefficient and delays the separation of the flow. 19,20 McWilliam et al used a morphing flap on a constant length in their aeroelastic optimization of the 10-MW wind turbine blade and investigated its effect on each speed compared with the baseline blade. The flap they added to the reference blade increased the AEP by 0.51%, while the contribution of aeroelastic optimization was above 10%.…”

Development of a Control Unit for the Angle of Attack of a Vertically Axial Wind Turbine

“…Controlling the angle of attack allows VAWTs to start operating earlier and achieve their cut-in speed (the minimum wind speed required for the turbine to start generating power) more effectively; -Performance at Different Wind Speeds-Wind speed is not constant, and it varies with height and atmospheric conditions. VAWTs experience changing wind speeds as the rotor rotates, which affects the angle of attack [17]. By actively controlling the angle, the turbine can optimize power production by adjusting to the wind speed changes.…”