Next: Wind Turbine Rotors Goal ?. Question 1 Divergent thinking consists of A) Selection of unique answer B) Brainstorming many ideas.

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