ASME Oral Presentation Competition

Stevens Institute of Technology

Mechanical Engineering Dept.

Senior Design 2005~06

April 1st, 2006

Presented By:

Lazaro Cosma

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Presentation Agenda

• Project Background• Project Objective• Wave Data Analysis• Design Selection Process• Final Conceptual Design• Detailed Design Description• Fabricated Prototype• Conclusion

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Project Background

• Importance of Renewable Energy– More environmentally conscious– Unlimited resource

• Major Sources of Renewable Energy– Wind– Solar– Wave

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Renewable Energy ComparisonWave Power Solar Power Wind Power

Energy Density and Predictability

High Low Low

Availability 90% 20%-30% 20%-30%

Potential Sites Virtually Unlimited Limited Very Limited

Environmental Issues None Visual Pollution Noise / Visual Pollution

Wave Energy Densities (MW)

Wave Energy has more potential than Wind and Solar Energies combined

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Wave Energy Locations• Three locations

– Shore

– Near shore

– Offshore

• Offshore has the most potential for harnessing energy

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Offshore Wave Energy

Advantages• Sea waves have high

energy densities• Negligible demand on

land use• Ability to secure

energy supplies in remote regions

• Limited negative environmental impact

Disadvantages• High structural

loading in extreme weather conditions

• Potential navigation hazard to ships

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Major Problems / Concerns

• Economic feasibility– Where are the current / future markets

• Offshore– Location requiring unit to be self- sustaining

– Powering from shore not feasible

• Maintenance and installation

• Engineering challenges– Harness energy at a cost that is competitive

– Efficiency

– Utilizing maximum wave motion / height for optimum power potential

– Scalability

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Project Objective

• Focus on small scale design versus industrial scale

• Develop device that harnesses wave energy to generate electrical power on a buoy– Off-shore location requires buoy to be self-

sustaining – Power will be stored in batteries to be

drawn from when needed– Power output in the 100’s of Watts range

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Design Location: Raritan Bay, New York Harbor

Data collected from the past 5 years and statistically analyzed for significant wave height and period

Wave Data Analysis

Wave Height Wave Period

Mean Height: 12.2 inches• 95% C.L.: 3.94~27.95 inches

Mean Period: 7.14 sec• 95% C.L.: 3.1~12.8 sec

Coney Island, Raritan Bay:Histogram of Significant Wave Heights

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2000

4000

6000

8000

Wave Height (inches)

Freq

uenc

y

Coney Island, Raritan Bay:Histogram of Significant Wave Periods

0

1000

2000

3000

4000

5000

Wave Period (seconds)

Freq

uenc

y

*C.L. = Confidence Level

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Design Selection Process

Identify Opportunities

Customer Needs Target Values

State of the Art Review

Product Architecture / Technical Analysis

Concept GenerationConcept Screening

and Scoring

Design Selection Final Design

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Final Conceptual Design

Spring Reel

Storage Batteries

Gearbox

Flywheel

Alternator

One Way Clutch

Spring-Reel Design

• Effectively converts linear motion to rotational motion• Cost effective design• Integrates device with buoy

• Integrates device with buoy• Modularity of components

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Spring Operated Reel

Function: Convert linear buoy motion into rotational shaft motion

Design Aim: Maximize angular velocity of input shaft

• Velocity dependant on reel diameter

• Spring must be strong enough to handle large waves, not too strong to suppress small waves

Power Springs

Output Shaft to Rectifier

Support with Bearings

Spring Housing

Power Springs are attached to the shaft at their inner ends and fixed to the spring housing at the outer ends.

Power Springs

Output Shaft to Rectifier

Support with Bearings

Spring Housing

Power Springs are attached to the shaft at their inner ends and fixed to the spring housing at the outer ends.

Power Springs

Output Shaft to Rectifier

Support with Bearings

Spring Housing

Power Springs are attached to the shaft at their inner ends and fixed to the spring housing at the outer ends.

Power Springs

Output Shaft to Rectifier

Support with Bearings

Spring Housing

Power Springs are attached to the shaft at their inner ends and fixed to the spring housing at the outer ends.

Power Springs

Spring Housing

Output Shaft to Clutch

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One-Way Clutch & GearboxOne-way Clutch

Function: Convert oscillatory motion of reel into unidirectional motion

Design Aim: Utilize a one-way clutch bearing that can handle maximum input torque with a desired FOS

Gearbox

Function: Increase shaft speed for flywheel / alternator system

Design Aim: Increase speed by reducing torque to optimize operating RPM for alternator

Transmits Torque

Freewheels to allow reel to rewind

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Flywheel & AlternatorFlywheel

Function: Maintain RPM at alternator

Design Aim: Maximize momentum on flywheel, while minimizing required weight

• Acts as a mechanical battery by storing kinetic energy

Alternator

Function: Convert mechanical shaft horsepower to usable electrical power

Design Aim: Maximize power output at minimum RPM

• Charge batteries stored on platform for later usage

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Fabricated Prototype

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Conclusion• Unique design concept

– Design integrates maintainability with function

– Utilizes rotary motion to capture wave motion

– Cost effective design when compared to linear generator designs

• Wave Power is a viable source of renewable energy– Important to continually push the technology

– Potential Markets are present

• Develop innovative solutions to today’s major issues

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Questions or Comments?

A Special Thanks to:

My Team Members - Biruk Assefa, Yuki Sato, Josh Ottinger

Advisor - Professor Kishore Pochiraju

Consultant - Mike Raftery

Institute Machine Shop - George Wohlrob