Composed Fluid–Structure Interaction Interface for Horizontal Axis Wind Turbine Rotor

2015 ◽  
Vol 10 (4) ◽  
Author(s):  
Dubravko Matijašević ◽  
Zdravko Terze ◽  
Milan Vrdoljak
Keyword(s):  
Wind Turbine ◽  
Numerical Models ◽  
Stress Test ◽  
Fluid Structure Interaction ◽  
Horizontal Axis ◽  
High Fidelity ◽  
Horizontal Axis Wind Turbine ◽  
Recovery Method ◽  
Fluid Structure ◽  
Structure Interaction

In this paper, we propose a technique for high-fidelity fluid–structure interaction (FSI) spatial interface reconstruction of a horizontal axis wind turbine (HAWT) rotor model composed of an elastic blade mounted on a rigid hub. The technique is aimed at enabling re-usage of existing blade finite element method (FEM) models, now with high-fidelity fluid subdomain methods relying on boundary-fitted mesh. The technique is based on the partition of unity (PU) method and it enables fluid subdomain FSI interface mesh of different components to be smoothly connected. In this paper, we use it to connect a beam FEM model to a rigid body, but the proposed technique is by no means restricted to any specific choice of numerical models for the structure components or methods of their surface recoveries. To stress-test robustness of the connection technique, we recover elastic blade surface from collinear mesh and remark on repercussions of such a choice. For the HAWT blade recovery method itself, we use generalized Hermite radial basis function interpolation (GHRBFI) which utilizes the interpolation of small rotations in addition to displacement data. Finally, for the composed structure we discuss consistent and conservative approaches to FSI spatial interface formulations.

scholarly journals Fluid Structure Interaction Analysis of Horizontal Axis Wind Turbine

2020 ◽  
Vol 8 (5) ◽  
pp. 3478-3482
Keyword(s):  
Yield Strength ◽  
Wind Turbine ◽  
Aluminium Alloy ◽  
Structural Steel ◽  
Fluid Structure Interaction ◽  
Horizontal Axis ◽  
Horizontal Axis Wind Turbine ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Strength Limit

Wind power is a clean energy source that we can rely on for long term use. A wind turbine creates reliable, cost effective pollution free energy. A Horizontal axis wind turbine (HAWT) with three blades having aerofoil profile NACA 2421 is modelled in CAD software and the performance of the turbine is investigated numerically using 3D CFD Ansys 18.1 software at rotor speeds varying from 1 to 7.5 Rad/sec at wind speeds ranging from 8 to 24 m/s. In order to ensure the turbine blades do not fail due to pressure loads and rotational forces, Fluid structure interaction is carried out by importing the surface pressure loads from CFD output on to static structural module, the rotational velocities are also imparted on the blades and FE analysis is carried out to estimate the equivalent von-Mises stress for structural steel as well as aluminium alloy. It is found that aluminium alloy blades are preferable than the structural steel blades. At high rotor speeds, stresses in the structural steel exceeding the yield strength limit. For aluminium alloy the stresses are below the yield strength limit.

scholarly journals Fluid–Structure Interaction Simulations of a Wind Gust Impacting on the Blades of a Large Horizontal Axis Wind Turbine

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 509 ◽  
Author(s):  
Gilberto Santo ◽  
Mathijs Peeters ◽  
Wim Van Paepegem ◽  
Joris Degroote
Keyword(s):  
Wind Turbine ◽  
Fluid Structure Interaction ◽  
Horizontal Axis ◽  
Wind Gust ◽  
Horizontal Axis Wind Turbine ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Computational Fluid Dynamics Cfd ◽  
Computational Structural Mechanics ◽  
Csm Model

The effect of a wind gust impacting on the blades of a large horizontal-axis wind turbine is analyzed by means of high-fidelity fluid–structure interaction (FSI) simulations. The employed FSI model consisted of a computational fluid dynamics (CFD) model reproducing the velocity stratification of the atmospheric boundary layer (ABL) and a computational structural mechanics (CSM) model loyally reproducing the composite materials of each blade. Two different gust shapes were simulated, and for each of them, two different amplitudes were analyzed. The gusts were chosen to impact the blade when it pointed upwards and was attacked by the highest wind velocity due to the presence of the ABL. The loads and the performance of the impacted blade were studied in detail, analyzing the effect of the different gust shapes and intensities. Also, the deflections of the blade were evaluated and followed during the blade’s rotation. The flow patterns over the blade were monitored in order to assess the occurrence and impact of flow separation over the monitored quantities.

scholarly journals Aeroelastic response of a multi-megawatt upwind horizontal axis wind turbine (HAWT) based on fluid–structure interaction simulation

2020 ◽  
Vol 5 (1) ◽  
pp. 141-154 ◽  
Author(s):  
Yasir Shkara ◽  
Martin Cardaun ◽  
Ralf Schelenz ◽  
Georg Jacobs
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Large Scale ◽  
Computational Simulation ◽  
Fluid Structure Interaction ◽  
Horizontal Axis ◽  
Aerodynamic Forces ◽  
Horizontal Axis Wind Turbine ◽  
Fluid Structure ◽  
Structure Interaction

Abstract. With the increasing demand for greener, sustainable, and economical energy sources, wind energy has proven to be a potential sustainable source of energy. The trend development of wind turbines tends to increase rotor diameter and tower height to capture more energy. The bigger, lighter, and more flexible structure is more sensitive to smaller excitations. To make sure that the dynamic behavior of the wind turbine structure will not influence the stability of the system and to further optimize the structure, a fully detailed analysis of the entire wind turbine structure is crucial. Since the fatigue and the excitation of the structure are highly depending on the aerodynamic forces, it is important to take blade–tower interactions into consideration in the design of large-scale wind turbines. In this work, an aeroelastic model that describes the interaction between the blade and the tower of a horizontal axis wind turbine (HAWT) is presented. The high-fidelity fluid–structure interaction (FSI) model is developed by coupling a computational fluid dynamics (CFD) solver with a finite element (FE) solver to investigate the response of a multi-megawatt wind turbine structure. The results of the computational simulation showed that the dynamic response of the tower is highly dependent on the rotor azimuthal position. Furthermore, rotation of the blades in front of the tower causes not only aerodynamic forces on the blades but also a sudden reduction in the rotor aerodynamic torque by 2.3 % three times per revolution.

scholarly journals Investigations of aerodynamic drag forces during structural blade testing using high fidelity fluid-structure interaction

2019 ◽  
Author(s):  
Christian Grinderslev ◽  
Federico Belloni ◽  
Sergio González Horcas ◽  
Niels N. Sørensen
Keyword(s):  
Drag Coefficient ◽  
Wind Turbine ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Test Facility ◽  
High Fidelity ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Drag Forces

Abstract. Aerodynamic loads on wind turbine blades that are tested for fatigue certifications, need to be known for planning and defining test loads beforehand. It is known that the aerodynamic forces, especially drag, are different for tests and operation, due to the entirely different flow conditions. In test facilities, a vibrating blade will move in and out of its own wake increasing the drag forces on the blade. This is not the case in operation. To study this special aerodynamic condition present during experimental tests, numerical simulations of a wind turbine blade during pull-release tests were conducted. High fidelity three dimensional computational fluid dynamics methods were used throughout the simulations. By this, the fluid mechanisms and their impact on the moving blade are clarified and through the coupling with a structural solver, the fluid-structure interaction is studied. Results are compared to actual measurements from experimental tests, verifying the approach. It is found that the blade experiences a high drag due to its motion towards its own whirling wake, resulting in an effective drag coefficient of approximately 5.3 for the 90 degree angle of attack. This large drag coefficient was implemented in a fatigue test load simulation, resulting in a significant decrease of moment along the blade, leading to less load applied than intended. The confinement from the test facility did not impact this specific test setup, but simulations with longer blades could possibly yield different conclusions. To the knowledge of the authors, this investigation including three dimensional effects, structural coupling and confinement is the first of its kind.

scholarly journals Investigations of aerodynamic drag forces during structural blade testing using high-fidelity fluid–structure interaction

2020 ◽  
Vol 5 (2) ◽  
pp. 543-560 ◽  
Author(s):  
Christian Grinderslev ◽  
Federico Belloni ◽  
Sergio González Horcas ◽  
Niels Nørmark Sørensen
Keyword(s):  
Drag Coefficient ◽  
Wind Turbine ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Test Facility ◽  
High Fidelity ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Drag Forces

Abstract. Aerodynamic loads need to be known for planning and defining test loads beforehand for wind turbine blades that are tested for fatigue certifications. It is known that the aerodynamic forces, especially drag, are different for tests and operation, due to the entirely different flow conditions. In test facilities, a vibrating blade will move in and out of its own wake, increasing the drag forces on the blade. This is not the case in operation. To study this special aerodynamic condition present during experimental tests, numerical simulations of a wind turbine blade during pull–release tests were conducted. High-fidelity three-dimensional computational fluid dynamics methods were used throughout the simulations. In this way, the fluid mechanisms and their impact on the moving blade are clarified, and through the coupling with a structural solver, the fluid–structure interaction is studied. Results are compared to actual measurements from experimental tests, verifying the approach. It is found that the blade experiences a high drag due to its motion towards its own whirling wake, resulting in an effective drag coefficient of approximately 5.3 for the 90∘ angle of attack. This large drag coefficient was implemented in a fatigue test load simulation, resulting in a significant decrease in bending moment along the blade, leading to less load being applied than intended. The confinement from the test facility did not impact this specific test setup, but simulations with longer blades could possibly yield different conclusions. To the knowledge of the authors, this investigation, including three-dimensional effects, structural coupling and confinement, is the first of its kind.

scholarly journals Aeroelastic response of a multi-megawatt upwind HAWT based on fluid-structure interaction simulation

2019 ◽  
Author(s):  
Yasir Shkara ◽  
Martin Cardaun ◽  
Ralf Schelenz ◽  
Georg Jacobs
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Large Scale ◽  
Aerodynamic Force ◽  
Computational Simulation ◽  
Fluid Structure Interaction ◽  
Horizontal Axis Wind Turbine ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Azimuthal Position

Abstract. With the increase demand for greener, sustainable and economical energy sources, wind energy has proven a potential promising sustainable source of energy. The trend development of wind turbines tends to increase rotor diameter and tower height to capture more energy. The bigger, lighter and more flexible structure is more sensitive to smaller excitations. To make sure that the dynamic behavior of the wind turbine structure will not influence the stability of the system and to further optimize the structure, a fully detailed analyses of the entire wind turbine structure is crucial. Since the fatigue and the excitation of the structure are highly depend on the aerodynamic forces, it is important to take blade-tower interaction into consideration in the design of large-scale wind turbines. In this work, an aeroelastic model that describes the interaction between the blade and the tower of a horizontal axis wind turbine (HAWT) is presented. The high-fidelity fluid-structure interaction (FSI) model is developed by coupling a computational fluid dynamics (CFD) solver with finite element (FE) solver to investigate the response of a multi-megawatt wind turbine structure. The results of the computational simulation showed that the dynamic response of the tower is highly depend on the rotor azimuthal position. Furthermore, rotation of the blades in front of the tower cause not only aerodynamic force pulls on the blade but a sudden reduction of the rotor aerodynamic torque by 2.3 % three times per revolution.

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