Numerical Fluid-Structure Interaction Study on the NREL 5MW HAWT

Abstract

Abstract. The development of reliable Fluid-Structure Interaction (FSI) simulation tools and models for the wind turbines is a critical step in the design procedure towards achieving optimized large wind turbine structures. Such approach will mitigate the aeroelastic instabilities like: torsional flutter, stall flutter and edgewise instability that introduce extra stresses to the turbine structure leading to reduced life time and substantial failures. In this study, FSI simulations were held using the commercial package Ansys v18.2 solvers as a preliminary step towards our on-going development of a reliable Open-Source solver. These simulations were applied to the full-scale rotor blades of the NREL 5MW reference horizontal axis wind turbine. The aerodynamic loads and structural responses computations were carried out using a steady-state FSI analysis. The computations were run on the Kyushu University multicore Linux cluster using the public domain openMPI implementation of the standard message passing interface (MPI). Finally, the results were validated against the Technical University of Denmark's (DTU) MIRAS aeroelastic code results as well as the widely used FLEX5-Q 3 UIC and FAST codes in different cases showing reasonable agreement. IntroductionThe increased potential for the extraction of wind energy has led to a considerable development in the wind turbines designs. The turbine blades are getting larger and thus introducing new load effects. The flexibility of large wind turbines yields an interaction between the fluid flow and the internal structure loading causing what is known as Fluid-Structure Interaction (FSI) or aeroelastic effects. The consequences of these effects are many instability problems like torsional flutter, stall flutter and edgewise instability imposing extra stresses on the blade structure through fatigue loads that potentially end up to wind turbine failures. Hence, developing reliable FSI simulation tools and models for the blades of wind turbines is a critical step towards developing and optimizing the large wind turbines designs. Many recent studies are centered around the FSI development. Hsu and Bazilevs [1] simulated a full scale turbine using a fully coupled 3D FSI approach by a low order FEM-based ALE-VMS technique. Rafiee et al.[2] investigated the aeroelastic behavior using modified BEM and CFD then constructed an iterative FSI approach. Wang et al. [3] established an FSI model using CFD and FEA with one-way coupling interface between them. Carrión et al.[4] applied a CFD-CSD method to perform aeroelastic

Structural optimization of H-type VAWT blade under fluid-structure interaction conditions

“…Lee et al [10] analyzed the displacement and torsion angle with time for different sections of HAWT blade considering the fluid-structure interaction. Halawa et al [11], Dose et al [12] and Borouji et al [13] studied the structural deformation, thrust and output power of 5 KW HAWT using the fluid-structure interaction simulation. Yu et al [14] used the CFD-CSD loose coupling method to calculate the elastic deformation of HAWT blade.…”