| Pub. Date | :Feb, 2019 |
|---|---|
| Product Name | : The IUP Journal of Mechanical Engineering |
| Product Type | : Article |
| Product Code | : IJME11902 |
| Author Name | : Amool A Raina, Saeed Farokhi and Kyle Wetzel |
| Availability | : YES |
| Subject/Domain | : Management |
| Download Format | : PDF Format |
| No. of Pages | : 18 |
The paper discusses the strategy for aerodynamic prediction and analysis of a 56 m blade using Computational Fluid Dynamics (CFD) tools. The aim of this study is to simulate the flowfield around a 3 MW wind turbine blade to study the flow physics dominated by the three-dimensional effects. This blade incorporates flatback airfoils on the inboard region of the blade used to improve aerodynamic performance in the root region. In order to reduce computation time and complexity, only one-third of the domain is modeled and a periodic boundary condition is imposed on the 120° periodic faces. A k- SST turbulence model is used as a solver for this simulation. Several features pertaining to 3D flowfield behavior are captured and studied. A comparison is made of the results obtained from RANS with those obtained from Boundary Element Method (BEM)-based methods. The flow past the flatback regions of the blade did not separate at the sharp edges of the flatback corners, as predicted by 2D simulation due to the presence of a dominant radial flow component in the span-wise direction which caused the flow to wrap around the trailing edge of the blade without corner separation. The paper presents a comparison of the inflow angles from CFD to those predicted by BEM.
Wind energy is a low-density source of power. In order to maximize the efficiency of wind turbine systems, it is important to minimize the losses in the translation of captured wind energy into mechanical energy. It is a well-recognized fact that the efficiency of mechanical systems cannot be increased beyond a certain level. On the contrary, rotor aerodynamics has been identified as one of the most important factors that also affect the efficiency of the system. Thus, in order to maximize the energy capture, it is necessary to have an optimally designed aerodynamic rotor. To determine the efficiency of any rotating turbo machinery, three approaches are available to analyze the flow around and downstream of a wind turbine: field or wind tunnel testing, which provides accurate results but is highly complex and expensive; analytical and semi-empirical models, which adopt simplifying assumptions and are thus not universally reliable; and Computational Fluid Dynamics (CFD), which probably offers the best support or alternative to direct measurements (Vermeer et al., 2003). There is a strong drive in the wind turbine industry for the development of yet larger wind turbines. It should be noted that there is limited literature that describes the aerodynamic behavior of large MW-scale wind turbines.
Wind energy, Wind turbine blade, 3D CFD, Aerodynamic performance, Flatback airfoils