Winglet design for vertical axis wind turbines based on a design of experiment and CFD approach

Abstract

Vertical axis wind turbines (VAWTs) have been attracting an increasing attention in recent years because of their potential for effectively using wind energy. The tip vortices from the VAWT blades have a negative impact on the power efficiency. Since a winglet has been proved to be effective in decreasing the tip vortex in the aerospace field, this paper numerically studies the aerodynamic effect of appending a winglet on the blade of a VAWT. Based on the theoretical motion pattern of the VAWT blade, this paper simplifies the three-dimensional fullscale rotor simulation to a one-blade oscillating problem in order to reduce the computational cost. The full rotor model simulation is also used in validating the result. The numerical approach has been validated by the experimental data that is available in the open literature. Six parameters are applied in defining the configuration of the winglet. The orthogonal experimental design (OED) approach is adopted in this paper to determine the significance of the design parameters that affect the rotor's power coefficient. The OED results show that the twist angle of the winglet is the most significant factor that affects the winglet's performance. A range analysis of the OED results produces an optimal variable arrangement in the current scope, and the winglet's performance in this variable arrangement is compared with the blade without a winglet. For the single blade study, the comparison result shows that the optimal 2 winglet can decrease the tip vortices and improve the blade's power performance by up to 31% at a tip speed ratio of 2.29. However, for the full VAWT case, the relative enhancement in the power coefficient is about 10.5, 6.7, and 10.0% for TSRs of 1.85, 2.29, and 2.52, respectively. The winglet assists in maintain the pressure difference between the two sides of the blade, thus weakening the tip vortex and improving the aerodynamic efficiency of the surface near the blade tip.

Performance Analysis of Reinforced Epoxy Functionalized Carbon Nanotubes Composites for Vertical Axis Wind Turbine Blade

“…The FEA modeling of the optimized VAWT with composite blades was carried out using the ANSYS Static Structural module [ 25 ], which is commonly used FEA modeling software. The FEA modeling procedure was applied to the optimized VAWT geometry.…”

Adjoint based optimisation for efficient VAWT blade aerodynamics using CFD

“…This approximation model can therefore be of sufficient accuracy to replace a full VAWT model during the optimisation process. Due to the iterative nature of the process, this means significant computing time savings overall (Zhang et al, 2019).…”

Technoeconomic study for the optimization of turbine size and wind farm layouts

“…Other research works on the renewable energy and its optimization approaches are addressed in the literature. 28,29 The literature review presented in the above section revealed that however there are a lot of studies conducted for optimization of wind turbine layouts using different techniques, there are lack of studies and a research gap regarding the procedure and methodology to take a technoeconomic decision of the optimal selection of wind turbine sizes, number, and distributions in a wind farm of a specified required output power. Accordingly, the main objective of the present is to adopt and present a new technoeconomic study approach based on the future worth method, cash flow diagram, and payback period for optimal selection of wind turbine sizes, numbers, and distributions from different alternatives.…”

“…Hou presented an economical study of optimization of repowering the offshore wind farm at close to the end of its life as a solution to extend the lifetime of the wind farm. Other research works on the renewable energy and its optimization approaches are addressed in the literature …”