Next: Wind Turbine Rotors Goal ?

Question 1  Divergent thinking consists of A) Selection of unique answer B) Brainstorming many ideas

Divergent and Convergent Thinking Divergent Convergent  Generating new ideas  Brainstorming  Optimize  Select Posed Problem New Ideas Answerable question, many ideas Unique answer

Effective Design  Teams should go through process several times  Be effective in transitioning  Know what process you are in

Grand Challenges from National Academy of Engineering

Societal and environmental considerations Limited 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 

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  

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  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 power mass flow rate

Available wind power kinetic energy per unit time [ J/s ] = [W] where units power in the wind Power?

Available wind power Note: wind power α air density (1.225 kg/m 3 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 Class Speed Power density [W/m 2 ] 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 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  Constant cord or  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