The evolution of the wake of a wind turbine contributes significantly to its operation and performance, as well as to those of machines installed in the vicinity. The inherent unsteady and three-dimensional (3D) aerodynamics of vertical axis wind turbines (VAWT) have hitherto limited the research on wake evolution. In this paper, the wakes of both a troposkien and a H-type VAWT rotor are investigated by comparing experiments and calculations. Experiments were carried out in the large-scale wind tunnel of the Politecnico di Milano, where unsteady velocity measurements in the wake were performed by means of hot wire anemometry. The geometry of the rotors was reconstructed in the open-source wind-turbine software QBlade, developed at the TU Berlin. The aerodynamic model makes use of a lifting line free-vortex wake (LLFVW) formulation, including an adapted Beddoes-Leishman unsteady aerodynamic model; airfoil polars are introduced to assign sectional lift and drag coefficients. A wake sensitivity analysis was carried out to maximize the reliability of wake predictions. The calculations are shown to reproduce several wake features observed in the experiments, including blade-tip vortex, dominant and minor vortical structures, and periodic unsteadiness caused by sectional dynamic stall. The experimental assessment of the simulations illustrates that the LLFVW model is capable of predicting the unsteady wake development with very limited computational cost, thus making the model ideal for the design and optimization of VAWTs.

References

References
1.
Paulsen
,
U.
,
Madsen
,
H.
,
Enevoldsen
,
K.
,
Nielsen
,
P.
,
Hattel
,
J.
,
Zanne
,
L.
,
Battisti
,
L.
,
Brighenti
,
A.
,
Lacaze
,
M.
,
Lim
,
V.
,
Heinen
,
H.
,
Berthelsen
,
P.
,
Carstensen
,
S.
,
de Ridder
,
E.
,
van Bussel
,
G.
, and
Tescione
,
G.
,
2011
, “
DeepWind—An Innovative Wind Turbine Concept for Offshore
,”
EWEA 2011 Conference
, Brussels, Belgium, Mar. 14–17, pp. 1–9.
2.
Mertens
,
S.
,
vanKuik
,
G.
, and
van Bussel
,
G.
,
2003
, “
Performance of an H-Darrieus in the Skewed Flow on a Roof
,”
ASME J. Sol. Energy Eng.
,
125
(
4
), pp.
433
440
.
3.
Balduzzi
,
A.
,
Bianchini
,
A.
,
Carnevale
,
E. A.
,
Ferrari
,
L.
, and
Magnani
,
S.
,
2012
, “
Feasibility Analysis of a Darrieus Vertical-Axis Wind Turbine Installation in the Rooftop of a Building
,”
Appl. Energy
,
97
, pp.
921
929
.
4.
Blackwell
,
B. F.
,
Sheldahl
,
R. E.
, and
Feltz
,
L. V.
,
1976
, “
Wind Tunnel Performance Data for the Darrieus Wind Turbine With NACA 0012 Blades
,” Sandia National Laboratories, Albuquerque, NM, Technical Report No.
SAND76-0130
.http://windpower.sandia.gov/abstracts/760130A.pdf
5.
Sheldahl
,
R. E.
,
1981
, “
Comparison Field Wind Tunnel Darrieus Wind Turbine Data
,” Sandia National Laboratories, Albuquerque, NM, Technical Report No.
SAND80-2469
.http://prod.sandia.gov/techlib/access-control.cgi/1980/802469.pdf
6.
Battisti
,
L.
,
Benini
,
E.
,
Brighenti
,
A.
,
Castelli
,
M. R.
,
Dell'Anna
,
S.
,
Dossena
,
V.
,
Persico
,
G.
,
Paulsen
,
U. S.
, and
Pedersen
,
T.
,
2016
, “
Wind Tunnel Testing of the DeepWind Demonstrator in Design and Tilted Operating Conditions
,”
Energy
,
111
, pp.
484
497
.
7.
Persico
,
G.
,
Dossena
,
V.
,
Paradiso
,
B.
,
Battisti
,
L.
,
Brighenti
,
A.
, and
Benini
,
E.
,
2017
, “
Time-Resolved Experimental Characterization of the Wakes Shed by H-Shaped and Troposkien Vertical Axis Wind Turbines
,”
ASME J. Energy Resour. Technol.
,
139
(
3
), p.
031203
.
8.
Paraschivoiu
,
I.
,
2002
,
Wind Turbine Design: With Emphasis on Darrieus Concept
,
Polytechnic International Press
, Montreal, QC, Canada.
9.
Shamsoddin
,
S.
, and
Porté-Agel
,
F.
,
2014
, “
Large Eddy Simulation of Vertical Axis Wind Turbine Wakes
,”
Energies
,
7
(
2
), pp.
890
912
.
10.
Bassi
,
F.
,
Ghidoni
,
A.
,
Perbellini
,
A.
,
Rebay
,
S.
,
Crivellini
,
A.
,
Franchina
,
N.
, and
Savini
,
M.
,
2014
, “
A High-Order Discontinuous Galerkin Solver for the Incompressible RANS and kω Turbulence Model Equations
,”
Comput. Fluids
,
98
, pp.
54
68
.
11.
Balduzzi
,
A.
,
Bianchini
,
A.
,
Gigante
,
F. A.
,
Ferrara
,
G.
,
Campobasso
,
M. S.
, and
Ferrari
,
L.
,
2015
, “
Parametric and Comparative Assessment of Navier-Stokes CFD Methodologies for Darrieus Wind Turbine Performance Analysis
,”
ASME
Paper No. GT2015-42663.
12.
Castelli
,
M. R.
,
Masi
,
M.
,
Battisti
,
L.
,
Benini
,
E.
,
Brighenti
,
A.
,
Dossena
,
V.
, and
Persico
,
G.
,
2016
, “
Reliability of Numerical Wind Tunnels for VAWT Simulation
,”
J. Phys.: Conf. Ser.
,
753
(
8
), p.
082025
.
13.
Bianchini
,
A.
,
Balduzzi
,
A.
,
Ferrari
,
L.
,
Ferrara
,
G.
,
Persico
,
G.
,
Dossena
,
V.
, and
Battisti
,
L.
,
2017
, “
A Combined Experimental and Numerical Analysis of the Wake Structure and Performance of a H-Shaped Darrieus Wind Turbine
,” Global Power and Propulsion Forum 2017, Zurich, Switzerland, Jan. 16–18, Paper No. GPPF-2017-51.
14.
Grasso
,
F.
,
van Garrel
,
A.
, and
Schepers
,
J.
,
2011
, “
Development and Validation of Generalized Lifting Line Based Code for Wind Turbine Aerodynamics
,”
AIAA
Paper No. 2011-146.
15.
Dossena
,
V.
,
Persico
,
G.
,
Paradiso
,
B.
,
Battisti
,
L.
,
Dell'Anna
,
S.
,
Benini
,
E.
, and
Brighenti
,
A.
,
2015
, “
An Experimental Study of the Aerodynamics and Performance of a Vertical Axis Wind Turbine in Confined and Unconfined Environment
,”
ASME J. Energy Resour. Technol.
,
137
(
5
), p.
051207
.
16.
Katz
,
J.
, and
Plotkin
,
A.
,
1991
,
Low Speed Aerodynamics
, Cambridge University Press, Cambridge, UK.
17.
van Garrel
,
A.
,
2003
,
Development of a Wind Turbine Aerodynamics Simulation Module
,
Energy Research Centre of the Netherlands
, Petten, The Netherlands.
18.
Drela
,
M.
, and
Youngren
,
H.
, 2018, “
Xfoil: Subsonic Airfoil Development System
,” accessed June 7, 2018, http://web.mit.edu/drela/Public/web/xfoil/
19.
Bhagwat
,
M. J.
, and
Leishman
,
G. J.
,
2001
, “
Stability, Consistency and Convergence of Time-Marching Free-Vortex Rotor Wake Algorithms
,”
J. Am. Helicopter Soc.
,
46
(
1
), pp.
59
71
.
20.
Viterna
,
L.
, and
Janetzke
,
D.
,
1981
, “
Theoretical and Experimental Power From Large Horizontal-Axis Wind Turbines
,” NASA Lewis Research Center, Cleveland, OH, Report No. TM-82944.
21.
Montgomerie
,
B.
,
2004
, “
Methods for Root Effects, Tip Effects and Extending the Angle of Attack Range to ±180 deg, With Application to Aerodynamics for Blades on Wind Turbines and Propellers
,” FOI, Swedish Defence Research Agency, Stockholm, Sweden, Report No. FOI-R-1305-SE.
22.
Leishman
,
J. G.
, and
Beddoes
,
T. S.
,
1989
, “
A Semi-Empirical Model for Dynamic Stall
,”
J. Am. Helicopter Soc.
,
34
(
3
), pp.
3
17
.
23.
Wendler
,
J.
,
Marten
,
D.
,
Pechlivanoglou
,
G.
,
Nayeri
,
C.
, and
Paschereit
,
C.
,
2016
, “
An Unsteady Aerodynamics Model for Lifting Line Free Vortex Wake Simulations of HAWT and VAWT in Qblade
,”
ASME
Paper No. GT2016-57184.
24.
Marten
,
D.
,
2015
, “
Implementation, Optimization and Validation of a Nonlinear Lifting Line Free Vortex Wake Module Within the Wind Turbine Simulation Code Qblade
,”
ASME
Paper No. GT2015-43265.
25.
Ferreira
,
C. S.
,
2009
, “
The Near Wake of the VAWT
,”
Ph.D. thesis
, Delft University of Technology, Delft, The Netherlands.https://repository.tudelft.nl/islandora/object/uuid%3Aff6eaf63-ac57-492e-a680-c7a50cf5c1cf
26.
Sant
,
T.
,
2007
, “
Improving BEM-Based Aerodynamic Models in Wind Turbine Design Codes
,”
Ph.D. thesis
, Delft University of Technology, Delft, The Netherlands.https://repository.tudelft.nl/islandora/object/uuid%3A4d0e894c-d0ad-4983-9fa3-505a8c6869f1
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