Investigating Three-Dimensional and Rotational Effects on Wind Turbine Blades by Means of a Quasi-3D Navier-Stokes Solver

2000 ◽  
Vol 122 (2) ◽  
pp. 330-336 ◽  
Author(s):  
P. K. Chaviaropoulos ◽  
M. O. L. Hansen
Keyword(s):  
Wind Turbine ◽  
Stokes Equations ◽  
Twist Angle ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Viscous Effects ◽  
Wind Turbine Blades ◽  
Mean Values ◽  
Power Curves

Three-dimensional and rotational viscous effects on wind turbine blades are investigated by means of a quasi-3D Navier-Stokes model. The governing equations of the model are derived from the 3-D primitive variable Navier-Stokes equations written in cylindrical coordinates in the rotating frame of reference. The latter are integrated along the radial direction and certain assumptions are made for the mean values of the radial derivatives. The validity of these assumptions is cross-checked through fully 3-D Navier-Stokes calculations. The resulting quasi-3D model suggests that three-dimensional and rotational effects be strongly related to the local chord by radii ratio and the twist angle. The equations of the model are numerically integrated by means of a pressure correction algorithm. Both laminar and turbulent flow simulations are performed. The former is used for identifying the physical mechanism associated with the 3-D and rotational effects, while the latter for establishing semiempirical correction laws for the load coefficients, based on 2-D airfoil data. Comparing calculated and measured power curves of a stall controlled wind turbine, it is shown that the suggested correction laws may improve significantly the accuracy of the predictions. [S0098-2202(00)02702-4]

Modelling the Flow Around Airfoils Equipped with Vortex Generators Using a Modified 2D Navier–Stokes Solver

2005 ◽  
Vol 127 (2) ◽  
pp. 223-233 ◽  
Author(s):  
I. G. Nikolaou ◽  
E. S. Politis ◽  
P. K. Chaviaropoulos
Keyword(s):  
Turbulent Flows ◽  
Stokes Equations ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
Vortex Generators ◽  
Navier Stokes ◽  
Complex Flow ◽  
Wind Turbine Blades ◽  
Production Term

Vortex generators (VGs) are commonly used for trimming the aerodynamic and aeroelastic performance of wind turbine blades by delaying flow separation. There is therefore a need for the development of reliable, still computationally affordable, models for blade designers to use to predict and enhance the aerodynamic characteristics of airfoils equipped with VGs. Such a model is proposed in the present paper, addressing in particular near-stall and post-stall airfoil performance. Starting from the three-dimensional Navier–Stokes equations that essentially describe the complex flow around a blade/VG configuration, a spanwise averaging procedure is applied, resulting in an equivalent set of two-dimensional equations, enriched with extra source terms. These terms are modelled using elementary vortex flow theory. In turbulent flows, the production term of the turbulent kinetic energy is also augmented by the vorticity induced by the VG. The model is evaluated by studying the flow past a blade section with and without VGs. An analysis of the performance of nine alternative VG configurations is also presented to demonstrate the sensitivity of the airfoil polars to the VG geometric parameters.

Analysis of Blunt Trailing Edge Airfoils

2003 ◽  
Author(s):  
K. J. Standish ◽  
C. P. van Dam
Keyword(s):  
Experimental Data ◽  
Wind Turbine ◽  
Turbine Blades ◽  
Navier Stokes ◽  
Computational Techniques ◽  
Wind Turbine Blades ◽  
Trailing Edge ◽  
Blunt Trailing Edge ◽  
Large Wind ◽  
Structural Volume

The adoption of blunt trailing edge airfoils for the inner regions of large wind turbine blades has been proposed. Blunt trailing edge airfoils would not only provide increased structural volume, but have also been found to improve the lift characteristics of airfoils and therefore allow for section shapes with a greater maximum thickness. Limited experimental data makes it difficult for wind turbine designers to consider and conduct tradeoff studies using these section shapes. This lack of experimental data precipitated the present analysis of blunt trailing edge airfoils using computational fluid dynamics. Several computational techniques are applied including a viscous/inviscid interaction method and several Reynolds-averaged Navier-Stokes methods.

Optimization of Aerodynamic Performance of Wind Turbine Blades

2013 ◽  
Vol 284-287 ◽  
pp. 518-522
Author(s):  
Hua Wei Chi ◽  
Pey Shey Wu ◽  
Kami Ru Chen ◽  
Yue Hua Jhuo ◽  
Hung Yun Wu
Keyword(s):  
Power Generation ◽  
Wind Turbine ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Aerodynamic Performance ◽  
Wind Power Generation ◽  
Generation System ◽  
Wind Turbine Blades ◽  
Rotor Design ◽  
Power Generation System

A wind-power generation system uses wind turbine blades to convert the kinetic energy of wind to drive a generator which in turn yields electricity, the aerodynamic performance of the wind turbine blades has decisive effect on the cost benefit of the whole system. The aerodynamic analysis and the optimization of design parameters for the wind turbine blades are key techniques in the early stage of the development of a wind-power generation system. It influences the size selection of connecting mechanisms and the specification of parts in the design steps that follows. A computational procedure and method for aerodynamics optimization was established in this study for three-dimensional blades and the rotor design of a wind turbine. The procedure was applied to improving a previously studied 25kW wind turbine rotor design. Results show that the aerodynamic performance of the new three-dimensional blades has remarkable improvement after optimization.

scholarly journals Development of a Three-Dimensional Geometry Optimization Method for Turbomachinery Applications

2004 ◽  
Vol 10 (5) ◽  
pp. 373-385
Author(s):  
Steffen Kämmerer ◽  
Jürgen F. Mayer ◽  
Heinz Stetter ◽  
Meinhard Paffrath ◽  
Utz Wever ◽  
...  
Keyword(s):  
Optimization Problem ◽  
Stokes Equations ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Optimization Techniques ◽  
Navier Stokes ◽  
Physical Parameters ◽  
Flow Solver ◽  
Flow Simulations ◽  
Sensitivity Equations

This article describes the development of a method for optimization of the geometry of three-dimensional turbine blades within a stage configuration. The method is based on flow simulations and gradient-based optimization techniques. This approach uses the fully parameterized blade geometry as variables for the optimization problem. Physical parameters such as stagger angle, stacking line, and chord length are part of the model. Constraints guarantee the requirements for cooling, casting, and machining of the blades.The fluid physics of the turbomachine and hence the objective function of the optimization problem are calculated by means of a three-dimensional Navier-Stokes solver especially designed for turbomachinery applications. The gradients required for the optimization algorithm are computed by numerically solving the sensitivity equations. Therefore, the explicitly differentiated Navier-Stokes equations are incorporated into the numerical method of the flow solver, enabling the computation of the sensitivity equations with the same numerical scheme as used for the flow field solution.This article introduces the components of the fully automated optimization loop and their interactions. Furthermore, the sensitivity equation method is discussed and several aspects of the implementation into a flow solver are presented. Flow simulations and sensitivity calculations are presented for different test cases and parameters. The validation of the computed sensitivities is performed by means of finite differences.

Design and Analysis of Wind Turbine Blades: Winglet, Tubercle, and Slotted

2013 ◽  
Author(s):  
Alka Gupta ◽  
Abdulrahman Alsultan ◽  
R. S. Amano ◽  
Sourabh Kumar ◽  
Andrew D. Welsh
Keyword(s):  
Power Generation ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Alternative Energy ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Wind Turbine Blade ◽  
Wind Turbine Blades ◽  
Wind Speeds ◽  
Governing Factor

Energy is the heart of today’s civilization and the demand seems to be increasing with our growing population. Alternative energy solutions are the future of energy, whereas the fossil-based fuels are finite and deemed to become extinct. The design of the wind turbine blade is the main governing factor that affects power generation from the wind turbine. Different airfoils, angle of twist and blade dimensions are the parameters that control the efficiency of the wind turbine. This study is aimed at investigating the aerodynamic performance of the wind turbine blade. In the present paper, we discuss innovative blade designs using the NACA 4412 airfoil, comparing them with a straight swept blade. The wake region was measured in the lab with a straight blade. All the results with different designs of blades were compared for their performance. A complete three-dimensional computational analysis was carried out to compare the power generation in each case for different wind speeds. It was found from the numerical analysis that the slotted blade yielded the most power generation among the other blade designs.

scholarly journals FSI in Wind Turbines: A Review

2020 ◽  
Vol 8 (3) ◽  
pp. 37
Author(s):  
Yogesh Ramesh Patel
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Stokes Equations ◽  
Turbine Blades ◽  
Fluid Structure Interaction ◽  
Arbitrary Lagrangian Eulerian ◽  
Wind Turbine Blades ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Deformable Structure

This paper provides a brief overview of the research in the field of Fluid-structure interaction in Wind Turbines. Fluid-Structure Interaction (FSI) is the interplay of some movable or deformable structure with an internal or surrounding fluid flow. Flow brought about vibrations of two airfoils used in wind turbine blades are investigated by using a strong coupled fluid shape interplay approach. The approach is based totally on a regularly occurring Computational Fluid Dynamics (CFD) code that solves the Navier-Stokes equations defined in Arbitrary Lagrangian-Eulerian (ALE) coordinates by way of a finite extent method. The need for the FSI in the wind Turbine system is studied and comprehensively presented.

Viscous and Aeroelastic Effects on Wind Turbine Blades. The VISCEL project. Part I: 3D Navier-Stokes Rotor simulations

Wind Energy ◽  
2003 ◽  
Vol 6 (4) ◽  
pp. 365-385 ◽  
Author(s):  
P. K. Chaviaropoulos ◽  
I. G. Nikolaou ◽  
K. A. Aggelis ◽  
N. N. Soerensen ◽  
J. Johansen ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Navier Stokes ◽  
Wind Turbine Blades

Computation of Hoisting Forces on Wind Turbine Blades Using Computation Fluid Dynamics

2013 ◽  
Vol 446-447 ◽  
pp. 452-457 ◽  
Author(s):  
Yong Wang ◽  
De Tian ◽  
Wei He
Keyword(s):  
Fluid Dynamics ◽  
Wind Turbine ◽  
Pitch Angle ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Azimuth Angle ◽  
Wind Turbine Blades ◽  
Mesh Model ◽  
Cfd Method ◽  
Yaw Angle

The hoisting forces on a 38.5m wind turbine blade in multiple positions are computed using the computational fluid dynamics (CFD) method. The computation model is constructed with the steady wind conditions, blade mesh model and the blade positions which are determined by the blade pitch angle, azimuth angle and rotor yaw angle. The maximal and minimal hoisting forces in three-dimensional coordinates are found and the corresponding pitch angle, azimuth angle and yaw angle are obtained. The change of the hoisting forces on wind turbine blades is analyzed. Suggestions are given to decrease the hoisting forces of the blade in open wind environment.

New Insight Into the Flow Around a Wind Turbine Airfoil Section1

2005 ◽  
Vol 127 (2) ◽  
pp. 214-222 ◽  
Author(s):  
F. Bertagnolio ◽  
N. N. Sørensen ◽  
F. Rasmussen
Keyword(s):  
Wind Turbine ◽  
Numerical Models ◽  
Turbine Blades ◽  
Three Dimensional ◽  
Unsteady Aerodynamics ◽  
Turbulence Models ◽  
Navier Stokes ◽  
Detached Eddy Simulation ◽  
Pitching Airfoil ◽  
Wind Turbine Airfoil

The objective of this paper is an improved understanding of the physics of the aeroelastic motion of wind turbine blades in order to improve the numerical models used for their design. Two- and three-dimensional Navier–Stokes calculations of the flow around a wind turbine airfoil using the k−ω SST and Detached Eddy Simulation (DES) turbulence models, as well as an engineering semiempirical dynamic stall model, are conducted. The computational results are compared to the experimental results that are available for both the static airfoil and the pitching airfoil. It is shown that the Navier–Stokes simulations can reproduce the main characteristic features of the flow. The DES model seems to be able to reproduce most of the details of the unsteady aerodynamics. Aerodynamic work computations indicate that a plunging motion of the airfoil can become unstable.

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