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Aerodynamics of a wind turbine
Author: Kosmacheva Anna
Supervisor: Jari Hämäläinen
Lappeenranta University of Technology
Technomatematics
Introduction
Wind turbine is a device that converts kinetic
energy from the wind into mechanical energy.
The smallest turbines are used for applications such as
battery charging or auxiliary power on sailing boats.
Large grid-connected arrays of turbines are becoming an
increasingly large source of commercial electric power.
Defects of wind turbine blades
There are some types of defects of wind turbine blades:
Influence of defects:
Energy losses
Noise generation
Porosity Wrinkles/Cracks Delamination
Problem statement
Main goal - analysis of the performance of the wind
turbine blades with and without defects
Subject of research – 2D-3D models of wind turbine
blade, 3D wind turbine model
Method – Computational Fluid Dynamics (CFD)
Literature review – 2D case
M. Edon (2010) “Numerical analysis of the Naca airfoils of a wind turbine blade”
J. Leary (2010) “Computational Fluid Dynamics analysis of a low cost wind turbine”
H. Cao (2011) “Aerodynamics analysis of small horizontal axis wind turbine blades by using 2D and 3D CFD modeling”
O. Badran “Two-equation turbulence models for turbulent flow over a NACA 4412 airfoil at angle of attack 15 degree”
I.H. Abbott (1959) “Theory of wind sections. Including a summary of airfoil data”
Literature review – 3D case
S.N. Prasad, S.S. Rao “Analysis of aerofoil blade using
ANSYS for a vehicle mounted micro wind turbine”
S. Guntura, C. Bak “Analysis of 3D stall models for wind
turbine blades using data from the MEXICO experiment”
V. Sajjan, R.A. Savanur (2009) ”CFD analysis of 500 kW
horizontal-axis wind turbine blades: straight and bent
cases”
C. Ghenai, A. Sargsyan “Wind energy”
Literature review - Defects
H. S. Toft, K. Branner “Distribution of defects in wind
turbine blades and reliability assessment of blades
containing defects”
S.N. Ganeriwala, M. Richardson “Modes indicate cracks in
wind turbine blades”
Wind Energy Department, Risø National Laboratory
(2002) “Guidelines for design of wind turbines”
Research plan (1)
CFD analysis of 2D wind turbine blade model with
different design
Simulation of 2D model with some defects
The profile of NREL S809
The profile of DU93-W-210
Research plan (2)
3D modeling of rotating blades without any fixed objects
Research plan (3)
Studying of rotating blades and stationary tower and
some parts of the terrain
NACA 4412
The NACA airfoils are airfoil shapes for aircraft wings
developed by the National Advisory Committee for
Aeronautics (NACA).
Lift, drag and moment coefficients
The lift is the force used to overcome gravity and the higher the
lift the higher the mass that can be lifted off the ground.
In order to maintain a constant speed the drag must be balanced
by a propulsion force delivered from an engine, and the smaller
the drag the smaller the required engine.
Flow in the vicinity of leading edge bubble
Stall angle – NACA 4412
Mesh
ANSYS ICEM
19890 QUAD elements
Computational conditions of aerofoil
simulation
Solver – ANSYS FLUENT 13.0
Simulation Type – Steady Simulation
Fluid Material – Air
Wind Speed – 45.48 m/s
Turbulent models – RNG K-E, Spalart-Allmaras
Boundary condition – velocity inlet, pressure-outlet,
Stationary wall with no slip shear condition
Numerical results – Static pressure
Inviscid, Angle of attack – 2
Khandakar Niaz
Morshed [1]
My results
Numerical results – Velocity Magnitude
My results
Khandakar Niaz
Morshed [1]
Inviscid, Angle of attack – 2
Numerical results – flow separation
Angle of attack
18
Angle of attack
20
Comparison with experiment [2]
2 4 6 8 10 12 14 16 18 200.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
Angle of attack
Lift
coeff
icie
nt
Experiment
K-E RNG
Spalart-Allmaras
References
1. Khandakar N. Morshed (2010) “Experimental and
numerical investigations on aerodynamic characteristics
of savonius wind turbine with various overlap ratios”
2. Robert N. Pinkerton “Calculated and measured
pressure distributions over the midspan section of the
NACA 4412 airfoil”
Thank you