the vawt in skew: stereo-piv and vortex modeling
DESCRIPTION
The VAWT in Skew: Stereo-PIV and Vortex Modeling. ir. C.J. Sim ã o Ferreira, M.Sc. K. Dixon, Dipl.-Ing. C. Hofemann, Prof. Dr. ir. G.J.W. van Bussel, Prof. Dr. ir. G. A.M. van Kuik 47th AIAA Aerospace Sciences Meeting 5 - 8 Jan 2009, Orlando World Center Marriott Orlando, Florida. Who - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/1.jpg)
![Page 2: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/2.jpg)
The VAWT in Skew:
Stereo-PIV and Vortex Modeling
ir. C.J. Simão Ferreira, M.Sc. K. Dixon, Dipl.-Ing. C. Hofemann, Prof. Dr. ir. G.J.W. van Bussel, Prof. Dr. ir. G. A.M. van Kuik
47th AIAA Aerospace Sciences Meeting 5 - 8 Jan 2009, Orlando World Center MarriottOrlando, Florida
![Page 3: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/3.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
3
• Who
• What
• Why
• How
• Where
• Result
s
Carlos, Kristian, Claudia, ...
Numerical & Experimental…
Effect of the skewed angle on wake
Upwind & Downwind blade passage
To understand the influence of the skew angle on the performance of the VAWT
Vertical Axis Wind Turbine (VAWT)
Table of contents
![Page 4: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/4.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
4
What ? VAWT
![Page 5: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/5.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
5
Skewed flow ->
Misalignment of the flow perpendicular to the ground
What VAWT in Skew
![Page 6: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/6.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing Why ?
VAWT operating under skewed flow
show a higher efficiency than VAWT
operating under normal conditions !
Why ?
![Page 7: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/7.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing How ? Numerical
3D unsteady free wake panel method
• Design and research tool
– capturing the 3D nature of a VAWT and its wake
• Allows to analyze the effect of skew in terms of
– bound circulation,
– shed and trailing vorticity
– torque, wake and flow asymmetry
• Validated by PIV and Smoke Trail Studies
![Page 8: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/8.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
8
How ? Numerical
![Page 9: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/9.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
9
Two blades:
NACA 0015 (trailing edge) NACA 0018 (quarter chord)
Tip speed ratio:
λ = 4
Wind speed:
10 m/s
Reynolds number:
8 x 10 4
How ? Experimental
l = 700 mm Z
X
Y
d= 570 mm
c = 60 mm
![Page 10: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/10.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
10
Wind
Y
X
Z
How ?
Low speed /Low turbulence Wind Tunnel
![Page 11: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/11.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
How ? 3D-Stereo-PIV
![Page 12: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/12.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
12
Where ? Upwind & Downwind
X
Y
0°
90°
180°measuring planes
wind
-120 mm
-0.42 y/R
120 mm
0.42 y/R
upwinddownwind
Numerical Upwind & Downwind Experimental Downwind
![Page 13: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/13.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
13
Results ? Tip vortex locus (Exp.)
Skew angles: = +20 = 0 = - 20
![Page 14: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/14.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
14
Results ? Tip vortex locus (Sim.)
Skew angles: = +20 = 0 = - 20
![Page 15: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/15.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
15
Results ? Tip vortex locus
![Page 16: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/16.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
16
Results ? Location of the wake
Azimuth angle:
= 90
Skew angles:
• = +20
• = 0
• = - 20
![Page 17: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/17.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
17
Results ? Trailing vorticity
Skew angles:
• = +20
• = 0
• = - 20
![Page 18: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/18.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
18
Results ? Shed vorticity
Skew angles:
• = +20
• = 0
• = - 20
![Page 19: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/19.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
19
Results ? Bound vorticity
Skew angles:
• = +20
• = 0
• = - 20
![Page 20: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/20.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
20
Results ? Normal Force
Skew angles:
• = +20
• = 0
![Page 21: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/21.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
21
Results ? Trailing vorticity
Skew
angles:
• = 0
• = 10
• = 20
• = 30
![Page 22: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/22.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
22
Results ? Shed vorticity
Skew
angles:
• = 0
• = 10
• = 20
• = 30
![Page 23: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/23.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
23
Results ? Tangential Force
Skew
angles:
• = 0
• = 10
• = 20
• = 30
![Page 24: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/24.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
24
Results ? Validation
![Page 25: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/25.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
25
Conclusions ?• The impact of the skew angle on the wake has
been shown by the 3D panel method • Skewed flow
– increases the performance of the VAWT– generates an asymmetry of the wake in z-direction– causes asymmetry of the expansion of the wake in y-
direction
• 3D unsteady free wake panel code – is able to replicate the effect of skew– shows the impact of the skew angle on the strength of
the wake for trailing and shed vorticity– shows the effect on bound vorticty as well as on normal
and tangential forces – is not able to capture the roll of motion
![Page 26: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/26.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing Questions ?
26
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The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
27
Results ? Induction in x-direction
Skew angles:
• = +20
• = 0
• = - 20
![Page 28: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/28.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
28
Results ? Induction in z-direction
Skew angles:
• = +20
• = 0
• = - 20
![Page 29: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/29.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
29
Why ?
![Page 30: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/30.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
Δt
30
How ? Stereo PIV / Displacement
![Page 31: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/31.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
31
NACA 0018: leading edge quarter chord
NACA 0015:flat tip trailing edge
What ? Blade configuration
![Page 32: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/32.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing Where ?
32
Wind
Y
X
Z
![Page 33: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/33.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
33
-60 mm
rotational
directions
X
Y
0°
90°
180°
measuring planes
wind
-180 mm
-120 mm
120 mm
180 mm
60 mm
upwinddownwind
Where ?
![Page 34: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/34.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
34
How ? Stereo PIV
Method:
• indirect
• monitoring due to tracer particles
• the displacement is pictured via two images, taken within Δt
• Stereo -> 2 cameras (rotated) to quantify the out of plain motions
Z
XY
x
y
zLaser
![Page 35: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/35.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
How ? Data Reduction
35
![Page 36: The VAWT in Skew: Stereo-PIV and Vortex Modeling](https://reader036.vdocuments.net/reader036/viewer/2022062423/568144a2550346895db16533/html5/thumbnails/36.jpg)
The
VA
WT
in S
kew
: S
tere
o-P
IV a
nd V
orte
x M
odel
ing
36
How ? Evaluation
Methode:
• longest vorticty level
• Integration over the enclosed area ( )
C SVds V ds