Novel structural modeling and mesh moving techniques for advanced fluid–structure interaction simulation of wind turbines

Abstract

SUMMARYIn this paper, we target more advanced fluid-structure interaction (FSI) simulations of wind turbines than reported previously. For this, we illustrate how the recent advances in isogeometric analysis of thin structures may be used for efficient structural mechanics modeling of full wind turbine structures, including tower, nacelle, and blades. We consider both horizontal axis and vertical axis wind turbine designs. We enhance the sliding-interface formulation of aerodynamics, previously developed to handle flows about mechanical components in relative motion such as rotor-tower interaction to allow nonstationary sliding interfaces. To accommodate the nonstationary sliding interfaces, we propose a new mesh moving technique and present its mathematical formulation. The numerical examples include structural mechanics verification for the new offshore wind turbine blade design, FSI simulation of a horizontal axis wind turbine undergoing yawing motion as it turns into the wind and FSI simulation of a vertical axis wind turbine. The FSI simulations are performed at full scale and using realistic wind conditions and rotor speeds.

Free-surface flow modeling and simulation of horizontal-axis tidal-stream turbines

“…Because the meshes on each side of the interface are nonmatching due to relative motion of the subdomains, the kinematic, level-set, and traction compatibility conditions are enforced in the weak sense. The sliding-interface technique was originally developed in [23] in the context of Isogeometric Analysis (IGA) [39,45], and successfully applied to simulate offshore wind turbines in [24,43,51,52], hydraulic arresting gears in [90], and kayak propulsion in [91]. The sliding-interface formulation was recently extended to the space-time (ST) VMS method [70,72,[75][76][77][78]80], and the extension is called the "ST Slip Interface (ST-SI)" method [79,82,84,85].…”

Isogeometric hyperelastic shell analysis with out-of-plane deformation mapping

“…Extension to general hyperelastic material can be found in [4]. The formulation has been successfully used in computation of a good number of challenging problems, including wind-turbine fluid-structure interaction (FSI) [3,[5][6][7][8][9], bioinspired flapping-wing aerodynamics [10], bioprosthetic heart valves [11][12][13][14][15], fatigue and damage [16][17][18][19][20][21], and design [22,23].…”

Pitch angle control of wind turbine systems in cold weather conditions using $$\mu$$ μ robust controller

“…Because of different areas of wind turbine performance, purpose in this article is, fixing the power and speed of the generator at the nominal value in the third performance section. Therefore, in this area by increasing the amount of wind to cut-out, the pitch angle has been increased, and this condition causes the reduction of power coefficient and the power is at its nominal value [4].…”

“…Considering turbine performance and its different operation areas, this paper aimed at designing controllers in the third operation area [4]. To be more precise, various types of control strategies are introduced to control and maximize power in this area.…”