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Next: Wind Turbine RotorsGoal ?
Question 1 Divergent thinking consists ofA) Selection of unique answerB) Brainstorming many ideas
Divergent and Convergent Thinking
Divergent Convergent
Generating new ideas
Brainstorming
Optimize Select
PosedProblem
NewIdeas
Answerablequestion,many ideas
Uniqueanswer
Effective Design
Teams should go through process several times
Be effective in transitioning Know what process you are in
http://www.engineeringchallenges.org/cms/challenges.aspx
Grand Challenges from National Academy of Engineering
Societal and environmental considerationsLimited fossil fuel supply of fossil fuels
Negative environmental impacts
Next Project Exercise 1 – 3 minutes Perceived need, motivation for design
Climate change and limited oil drives need for other energy sources
Function, approach
Physical phenomena
Embodiment, general design concept
Artifact Instance
Artifact Type
Next Project Exercise 1 Perceived need, motivation for design
Climate change and limited oil drives need for other energy sources
Function, approach Solar, hydro, wind (brainstorm solutions)
Physical phenomena Radiation, fluid mechanics/momentum
Embodiment, general design concept Solar cells, wave energy converter, wind turbine
Wind Turbine Project 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 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
Limited supply of fossil fuels Negative environmental impacts of burning Harness wind energy in a safe, efficient, durable
manner
Educational considerations Relatively inexpensive to build and test in
academic timeframe Multidisciplinary aspects
Why build and test once? Real-world
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?
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? 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 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
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 powerWhat parameters might we vary in the wind turbine
design? Primary Pitch of blades, which in turn affects angle of attack Cord/shape of blades
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 Estimation and potential wind
resource:speed and direction
Factors that affect wind: Geographical - global patterns,
land and sea breezes, valley and mountain winds, etc.
Meteorological - inter-annual, annual (seasonal) and diurnal (time of day)
Available wind powermass flow rate
Available wind power
kinetic energy per unit time[ J/s ] = [W]
where
units
units
power in the wind
Power?
Available wind power
Note:wind power α air density (1.225 kg/m3 at standard cond.)wind power α area swept by the rotorwind power α cube of the wind velocity
Power density = wind power per unit area
Available wind power
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
Wind power density classes at 30 meters
x2
x10
Wind Power
Wind Tunnel Air Velocity: 5 m/s
Given: Design Goal:
Maximize Power Generated for a Turbine Design
Constraints and Materials 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 VariablesWe’ll discuss the details of thesePrimary Pitch of blades, which in turn affects angle of
attack Number of blades <=12 Blade cord
Constant cordor
Variable cord
Break – end of week 1 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