Transcript Computational Wind Tunnel: A Tool for Rotorcraft

Wind Energy Technology
Through History
R Ganesh Rajagopalan
Iowa State University
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The Beginning
“Of all the forces of nature, I should think
the wind contains the greatest amount of
power” - Lincoln
Wind energy has been harnessed for a
very long time dating back to the Pharos
who used the wind to sail the Nile.
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Chronology of Wind Energy History
Technology development in wind energy
can be traced to the following periods.
 Ancient History: 200 BC – 1100 AD
 Medieval History: 1100 AD – 1800 AD
 Industrial Revolution: 1800 AD -1900 AD
 Age of Electric Electricity:1900-1945
 Large Scale Research Turbines: 1970s
 Wind Farm Development :19803
Ancient History
Greek Engineer Heron of Alexandria used
wind driven wheel to power a musical
instrument in the 1st century AD.
The blades spin about a
horizontal axis.
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Ancient History – Islamic World
Simple panemones that spin about a vertical
axis for grinding grain. Sails and wood were
commonly used as material. Drag Driven.
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Lift Driven Sail Type Mills
Sail type mills both spinning about the horizonal
axis and vertical axis were common during the
ancient period. No direct knowledge of
aerodynamics was used but practiced
naturally.
Lift Driven.
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Medieval History (Post Mills)
Crusaders brought the wind energy technology to
Europe. Simultaneous development in England
and France. The English used metal parts and
roller bearings to improve the life of machine.
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The Dutch Mills
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Dutch made many design improvements.
Supported the sails with wooden bars and
placed them away from the leading edge to
improve aerodynamic efficiency. Used metal
sheets instead of sails and introduced the
concept of speed control with shutters and
flaps during rough weather.
Use of wind power declined in Europe with the
introduction of steam engines during the
industrial revolution.
Dutch Tower Mills
The cap of the tower
rotates using a second
rotor for yaw control.
 The blades are twisted
from root to tip to become
aerodynamically more
efficient.
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The New World & Water Pumping
In the beginning of the Nineteenth Century
wind mills were common in the east coast of
the US around German and Dutch settlements.
The pioneers carried the technology with them
westward for water pumping. Halladay
invented the self regulating all metal wind
mill with blade pitch speed control.
Introduction of the vane to turn into or away
from the wind becomes the standard Eclipse
design.
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All Metal US Windmill
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Metal parts for blades and tower become
standard for wind turbines (Perry Wheel).
1900: US Windmill’s Success
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Shipped as parts and was assembled with
minimal tools and erected easily with local labor.
Parts were readily available and maintenance
was easy (transportation and O&M).
Structure and Material: Durable and Strong
galvanized steel
Minimum number of parts: Capital cost is
economical.
Efficient Aerodynamics and self governing in
speed and orientation (Control).
Rural Electrification
A windmill used to generate electricity is
commonly called a wind turbine. Until the 1960
wind turbines were commonly used to generate
electricity on farms. The Jacob turbine (14’
dia.) could deliver one 1KW in a 14 mph wind,
an average power consumed by a typical
household. Rural Electrification stopped further
growth in wind turbine technology and
manufacturing as electricity was cheaply
available every where.
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MW Size Wind Turbine
Smith Putnam Machine (Grandpa’s Knob)
 Built During WW II at Rutland Vermont
 Rated capacity 1.25 MW
 53 meters diameter
 Structural Steel
 Lost a Blade in 1945
and was decommisioned.
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Technology Divisions in DOE
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The Oil crisis of the 1970s brought wind
energy into focus again. Government labs
started scientific study of wind turbines which
included wind resource characterization.
Rocky Flats – Small HAWTs < 100 kW
NASA Lewis – Large HAWTs > 100 kW
Sandia Labs – VAWTs
PNL – Wind Prospecting - Resource
DOE – Innovative Designs
The “Mod” Series
Mod 0 – Plum Brook, Ohio
 Mod 1 – Boone, North Carolina
 Mod2 – Washington, Calif, & Wyoming
 Mod 5 - Oahu, Hawaii
Very Expensive Research turbines meant to be
technology drivers.
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Mod 0
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NASA Plum Brook
200 kW
Downwind rotor
Lattice Tower
Partial span pitch
Speed control
Mod 1
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Boone, North Carolina
2 Megawatt
200 foot
Downwind
Acoustic Problems
Mod 2
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2 Megawatt
200 feet diameter – upwind
Three units at Goldendale, Washington
One at Solano, California
One at Medicine Bow, Wyoming
All Steel Construction
Mod 5b
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Oahu, Hawaii
Built in Seattle
Shipped with Crane
330 feet
3.2 Megawatt
Steel tubular Tower
SANDIA VAWT Turbines
The Darrieus type Vertical
axis wind turbines were
developed by SANDIA and
A 34 meter diameter
Instrumented Turbine
was installed in Bushland,
TX for collecting data.
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Wind Farm Development
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Beginning with 1980 and california tax
incentives, wind farms with multiple number of
turbines at a site have become common and
are being commercially exploited.
Most of the modern wind farm turbines are
around 1.5 MW. The new trend is around 2.4
MW as that is the limitation imposed by land
based transportation logistics.
Conclusion
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The technology drivers of wind energy
conversion systems to-day are the same as it
was 50 or 500 years ago.
Aerodynamics and Control, Structure and
Materials, Mechanics and Vibration,
Transportation and Logistics, O&M and
Reliability and above all cost.