Next: Wind Turbine Rotors
Goal ?
Question 1
Divergent thinking consists of
A) Selection of unique answer
B) Brainstorming many ideas
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Divergent and Convergent Thinking
Divergent
Posed
Problem
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Convergent
Answerable
question,
many ideas
New
Ideas
Generating new ideas
Brainstorming
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Optimize
Select
Unique
answer
Effective Design
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Teams should go through process several times
Be effective in transitioning
Know what process you are in
Grand Challenges from National Academy of
Engineering
http://www.engineeringchallenges.org/cms/challenges.aspx
Societal and environmental considerations
Limited fossil fuel supply of fossil fuels
Negative environmental impacts
Next Project Exercise 1 – 3 minutes
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Perceived need, motivation for design
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Climate change and limited oil drives need for other energy sources
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Function, approach
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Physical phenomena
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Embodiment, general design concept
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Artifact Instance
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Artifact Type
Next Project Exercise 1
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Perceived need, motivation for design
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Function, approach
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Solar, hydro, wind (brainstorm solutions)
Physical phenomena

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Climate change and limited oil drives need for other energy
sources
Radiation, fluid mechanics/momentum
Embodiment, general design concept

Solar cells, wave energy converter, wind turbine
Wind Turbine Project
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Embodiment, general design concept

We’re going to converge on the choice of a wind turbine to
generate electrical energy from energy of wind
Atlantic City, NJ
Goal: Maximize
Power Output
How?
Wind Turbine Project
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Turbines tested indoors under controlled conditions
A single metric for success - amount of electricity
generated
Vary parameters
Design process will be executed using theoretical
calculations - build and test ONCE at end!
Why a Wind Turbine?

Societal and environmental considerations
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Limited supply of fossil fuels
Negative environmental impacts of burning
Harness wind energy in a safe, efficient, durable manner
Educational considerations

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Relatively inexpensive to build and test in academic
timeframe
Multidisciplinary aspects
Why build and test once?
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Real-world
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Do not have resources (time, money, materials) to build and
test multiple solutions
Need to use science principles and other constraints
Calculate solutions based on science and math rather than just
“tinkering” or “junk-yard” design
We can not always build
and test a large number
of design instances
Single ‘Real’ Test
Relation to your studies

What engineering courses are linked to this project?

What other courses or aspects may be important?
Relation to your studies

What engineering courses are linked to this project?
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Fluid Flow (ChE, ME, CEE)
Statics and Dynamics (ME, CEE, ECE)
Solid Mechanics (CEE, ME)
Power Conversion (ECE)
Electricity and Magnetism (ME, ECE, CEE)
What other courses or aspects may be important?
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Math – Integration and Vectors
Computer Science – Programming
Material Science
Economics
Environmental studies
Grid Issues
Construction
Land Use
Durability
Wind Turbines
Dr. Bakrania
2 Main Classes of Wind Turbines

Horizontal Axis

Vertical Axis
(Krieth and West 1997)
Inside a Wind Turbine

http://www1.eere.energy.gov/windandhydro/wind_how.html
Main parts
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Rotor – hub + blades
Drive train – inside rotating parts gear rotor up to
generator
Generator – converts mechanical energy to electrical
energy
Yaw system – keeps rotor aligned and oriented
Tower and foundation – provide height and stability
Electrical system – allows integration to grid
Controls – consists of sensors and actuators
Wind Turbine Videos

http://www.youtube.com/watch?v=CqEccgR0q-o
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http://www.youtube.com/watch?v=UJn2_lLRLrg
Estimate Performance by
Parametric Design on Computer
Parameters and Constraints
Small group exercise 3 – 5 minutes
What will be important factors to consider regarding wind
turbine design?
 Given constraints, materials and available wind power
What parameters might we vary in the wind turbine design?
Primary
 Pitch of blades, which in turn affects angle of attack
 Cord/shape of blades
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Constant cord – to make simple rectangular blades
Variable cord – to make another shape (triangle, parallelogram, etc.)
Secondary
 Number of blades <=12
 Radius <= 0.5 meter
Available wind power
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Estimation and potential wind
resource:
speed and direction
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Factors that affect wind:
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Geographical - global patterns,
land and sea breezes, valley
and mountain winds, etc.
Meteorological - inter-annual,
annual (seasonal) and
diurnal (time of day)
Available wind power
mass flow rate
Available wind power
units
Power?
kinetic energy per unit time
[ J/s ] = [W]
units
where
power in the wind
Available wind power
Note:
wind power α air density (1.225 kg/m3 at standard cond.)
wind power α area swept by the rotor
wind power α cube of the wind velocity
Power density = wind power per unit area
Available wind power
Wind power density classes at 30 meters
Wind Power
Class
Speed
Power
density
[W/m2]
1
0-5.1
0-160
2
5.1-5.8
160-240
3
5.8-6.5
240-320
4
6.5-7.0
320-400
5
7.0-7.4
400-480
6
7.4-8.2
480-640
7
8.2-11.0
640-1600
x2
x10
Wind Power
Given:
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Wind Tunnel Air Velocity:
5 m/s
Design Goal:

Maximize Power
Generated for a Turbine
Design
Constraints and Materials
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Max diameter of wind turbine = 1 meter
Max number of blades is 12
Hub is given and has a radius of 0.05 meter made of
plastic
Must be a horizontal axis wind turbine
Blades will be thin flat plates of given material (theory and
computer code with aerodynamics of blades/airfoils
provided)
Blades attached to hub with wooden dowel rods
Parameters and/or Variables
We’ll discuss the details of these
Primary
 Pitch of blades, which in turn affects angle of attack
 Number of blades <=12
 Blade cord
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Constant cord
or
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Variable cord
Break – end of week 1
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We’ll use math and science principles to conduct model
simulations to predict optimized performance conditions
here, rather than many, many experiments as we did in
the bottle rocket project
So let’s get some practice with MATLAB
MATLAB tutorial