The behaviors of tip displacement, maximum stress, and natural frequency of vibration as a function of blade length are investigated for extendable wind turbine blades. A three-dimensional linear elasticity finite-element model of the blade is used along with a typical profile and representative material properties. The quasi-linear response and free vibration behavior are investigated for a sequence of blade geometries. These estimates are intended to give approximate measures of expected changes in the elastic and dynamic field as the operating length changes and provide preliminary guidelines for this novel class of structure.

References

References
1.
Wind Power Monthly
,
2015
, “
10 Biggest Turbines in the World
,”
Windpower Offshore
,
London, UK
.
2.
Pasupulati
,
S. V.
,
Wallace
,
J.
, and
Dawson
,
M.
,
2005
, “
Variable Length Blades Wind Turbine
,”
IEEE Power Engineering Society General Meeting
, San Francisco, CA, June 12–16, pp.
2097
2100
.
3.
Imraan
,
M.
,
Sharma
,
R. N.
, and
Flay
,
R. G. J.
,
2011
, “
Wind Tunnel Testing of a Telescopic Blade Wind Turbine
,”
ASME
Paper No. POWER2011-55070.
4.
Imraan
,
M.
,
Sharma
,
R. N.
, and
Flay
,
R. G. J.
,
2009
, “
Telescopic Wind Turbines to Capture Energy at Low Wind Speed
,”
ASME
Paper No. ES2009-90118.
5.
Tartibu
,
L. K.
,
Kilfoil
,
M.
, and
Van Der Merwe
,
A. J.
,
2012
, “
Vibration Analysis of a Variable Length Blade Wind Turbine
,”
Int. J. Adv. Eng. Technol.
,
4
(
1
), pp.
630
639
.
6.
McCoy
,
T. J.
, and
Griffin
,
D. A.
,
2008
, “
Control of Rotor Geometry and Aerodynamics: Retractable Blades and Advanced Concepts
,”
Wind Eng.
,
32
(
1
), pp.
13
26
.
7.
Talbot
,
J. P.
, and
Woodhouse
,
J.
,
1997
, “
The Vibration Damping of Laminated Plates
,”
Composites, Part A
,
28
(
12
), pp.
1007
1012
.
8.
Reddy
,
J. N.
,
2006
,
An Introduction to the Finite Element Method
,
3rd ed.
,
McGraw-Hill
,
New York
.
9.
Griffin
,
D. A.
,
2002
, “
Blade System Design Studies Volume I: Composite Technologies for Large Wind Turbine Blades
,”
Sandia National Laboratories
, Albuquerque, NM, Report No. SAND2002-1879.
10.
Zhu
,
J.
,
Xin
,
C.
,
Pan
,
P.
, and
Rongrong
,
G.
,
2012
, “
Static and Dynamic Characteristics Study of Wind Turbine Blade
,”
Adv. Mater. Res.
,
383–390
, pp.
1895
1900
.
11.
Cai
,
X.
,
Zhu
,
J.
,
Pan
,
P.
, and
Gu
,
R.
,
2012
, “
Structural Optimization Design of Horizontal-Axis Wind Turbine Blades Using a Particle Swarm Optimization Algorithm and Finite Element Method
,”
Energies
,
5
(
11
), pp.
4683
4696
.
12.
TPI Composites
,
2003
, “
Cost Study for Large Wind Turbine Blades: WindPACT Blade System Design Studies
,”
Sandia National Laboratories
, Albuquerque, NM, Report No. SAND2003-1428.
You do not currently have access to this content.