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DESIGN OF AIRFOILS FOR WIND TURBINE BLADES. Presented by Parezanovic Vladimir Faculty of Mechanical Engineering Belgrade University. The Objectives. Simulate the airflow around selected well-known airfoils Obtain sufficient level of agreement between experimental and simulated data
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DESIGN OF AIRFOILS FOR WIND TURBINE BLADES Presented by Parezanovic Vladimir Faculty of Mechanical Engineering Belgrade University
The Objectives • Simulate the airflow around selected well-known airfoils • Obtain sufficient level of agreement between experimental and simulated data • Introduce “Virtual Prototyping” into the design process
The process • Importing or designing the geometry • Generating the mesh • Computational model setup • Iteration and monitoring • Results • Post-processing
Geometry and airfoils • Geometry is designed or imported • Airfoils investigated: • NACA 63(2)215 • FFA-W3-211 • A-Airfoil
Mesh generation • The resolution of the mesh can affect computations in many ways, most important are: • Accuracy • Computing time • Some facts about mesh used: • Around 14000 elements • 160 elements on the airfoil • Quadrilateral shaped cells • Cell size varies from 0.002 m2 up to 1.6 m2
Flow conditions • Conditions corresponding to those in wind tunnel experiments: • Low Reynolds number (1.8 - 3.0x106) • Free flow velocities around 25m/s • Low turbulence intensity
Numerical model • What kind of flow is modeled? • To what level of approximation? • What is expected to happen? • Setup in this case: • For NACA 63(2)215 and FFA-W3-211 model is fully turbulent • Laminar/turbulent transition modeled for A-Airfoil • k-ω SST turbulence model is used in all cases
A-Airfoil NACA63(2)215 FFA-W3-211 Lift and pitching moment coeff. curves (left), Drag coefficient curve (right) (A-Airfoil) Lift and pitching moment coeff. curves (left), Drag coefficient curve (right) (FFA-W3-211) Lift and pitching moment coeff. curves (left), Drag coefficient curve (right) NACA63(2)215 Results
Interpretation • Simulation results agree with experimental data to within 10% • The model is more exact for airfoils less susceptible to laminar/turbulent transition effects • Lift easier to predict than drag • A model with the ability to predict laminar/turbulent transition is needed
What was all this about? • MONEY! • EFFICIENCY • ENVIRONMENT