Upload
devi-renewable-energies
View
1.457
Download
3
Tags:
Embed Size (px)
Citation preview
Jarek Puczylowski - AG TWiSt / ForWind
Wind Energy lecture 02.12.2010 1
Jarek
Wind Energy lecture 02.12.2010 2
Wind Energy lecture 02.12.2010 3
Outline
- variety of wind turbines / classification
- drag coefficient and drag force (example: Persian Windmill)
- aerodynamics of an airfoil
- lift coefficient and lift force (example: Darrieus Rotor)
- history of wind turbines
Wind Energy lecture 02.12.2010 4
variety of wind turbines
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
different kinds of WECs
5
wind turbine
horizontal axiswind turbine
vertical axiswind turbine
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
different kinds of WECs
6
wind turbine
“drag” based wind turbines
“lift” based wind turbines
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
7
drag force based wind turbines
What is drag?
wind velocity v
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
8
drag force based wind turbines
What is drag?
wind velocity v
power of the wind
force acting on the body?
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
9
drag force based wind turbines
What is drag?
wind velocity v
power of the wind
force acting on the body?
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
10
drag force based wind turbines
What is drag?
wind velocity v
power of the wind
force acting on the body?
different shapes have different air resistances, i.e. different
drag coefficients cdcd = 0,34
cd = 1,33
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
11
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
12
sphere
cd is dependent on shape and Re
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
13
drag force based wind turbines
Persian windmill year 500-900 a.d.
How can we estimate the maximum power?
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
14
drag force based wind turbines
v = const
cd = 1.1
power estimation of a persian windmill
tip speed ratio
cp
tip speed ratio
cp,max =0,16
tip speed ratio for drag force based wind turbines < 1
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
15
drag force based wind turbines
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
16
lift force based wind turbines
airfoil design
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
17
lift force based wind turbines
How does lift occur?
vup
vdown
FL
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
18
lift force based wind turbines
How does lift occur?
vup
vdown
Bernoulli Equation(strong simplification of Navier-Stokes-Eq.,
i.e. no viscosity, stationary, novorticity)
1
2!u2
+ p = const
negative
FL
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
19
lift force based wind turbines
How does lift occur?Bernoulli Equation
(strong simplification of Navier-Stokes-Eq., i.e. no viscosity, stationary, novorticity)
1
2!u2
+ p = const
negative
Pup
Pdown
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
20
Why is vup larger than vdown?
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
21
Why is vup larger than vdown?
vup
vdown
starting vortex
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
22
Why is vup larger than vdown?
vup
vdown
starting vortex
angular momentumconservation
starting vortex
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
23
Why is vup larger than vdown?
vup
vdown
starting vortex
angular momentumconservation
starting vortex
wind velocity circulating vortex vup > vdown
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
24
Forces acting on an airfoil
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
25
Forces acting on an airfoil
FL = cL(Re,!) · 12"Au2
FD = cD(Re,!) · 12"Au2
Flift
Fdrag
F
cL = Lift coefficient
wind velocity v
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
26
measuring lift (and drag) coefficients of airfoils
2 force sensors measure FL and FD
80 pressure sensors measure pressure distribution along the wall
wind velocity v
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
27
measuring lift coefficients of airfoils
FL = cL(Re,!) · 12"Au2
2 force sensors measure FL and FD
80 pressure sensors measure pressure distribution along the wall
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
28
measuring lift coefficients of airfoils
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
29
Lift force based wind turbines
example:
Darrieus wind turbine
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
30
wind velocity v
velocity due to rotation u
total velocity
FL
FD
tip speed ratio for Darrieus rotors > 3
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
31
wind velocity v
velocity due to rotation u
total velocity
FL
FD
FD
FL
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
32
wind velocity v
velocity due to rotation u
total velocity
FL
FD
FD
FL
FD
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
33
wind velocity v
velocity due to rotation u
total velocity
FL
FD
FD
FL
FD
FD
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
34
wind velocity v
FL
FD
FD
FL
FD
FD
0° assist rotation
180° assist rotation
90°oppose rotation
270°oppose rotation
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
35
History of wind turbines
Denmark 1891
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
36
History of wind turbines
Russia 1931
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
37
History of wind turbines
USA 1942 - 50kW
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
38
History of wind turbines
Germany 1942
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
39
History of wind turbines
USA 1943 - 70kW
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
40
History of wind turbines
UK 1956 - 100kW
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
41
History of wind turbines
Denmark 1957 -200kW
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
42
History of wind turbines
France 1958 - 800kW
Wind Energy lecture 02.12.2010
Jarek Puczylowski - AG TWiSt / ForWind
43
History of wind turbines
Germany 1982 - 3000kW