11/01/05Wave Energy Power Generator2 Presentation Agenda Proposal Feedback –Project Scope –Target Values Concept Evaluation –Concept Screening / Scoring –Design Selection Technical Approach –Wave Data Statistics –Mathematical Model & Simulation –Product Architecture / Geometric Layout Subsystems –Cable / Reel –Mechanical Rectifier / Gearbox –Generator / Alternator Project Budget Conclusion

11/01/05Wave Energy Power Generator3 Project Scope/Objective Project Focus: Device that harnesses wave energy to generate electrical power on a buoy –Off-shore location requires buoy to be self-sustaining –Power output in the 100’s of Watts range Power will be stored in batteries to be drawn from when needed Benefits of wave over solar –Higher Energy Densities –Availability / Reliability

11/01/05Wave Energy Power Generator4 Target Values Metric No. Need Nos. MetricUnits Marginal Value Ideal Value 11Power output per cost of unitWatts / $>.25>.5 22Power OutputWatts> 100>300 33,4Working PeriodMonths>6>12 43,4,6Number of moving componentsNumber<6<4 55Maximum height of wave allowedFeet>2>6 66,8Number of componentsNumber<8<5 77Cost of Repair at catastrophic failureDollars<500<100 86,8WeightPounds< Size Volume (ft 3 ) <15<8

11/01/05Wave Energy Power Generator5 Concept Screening Relative PerformanceRating Worse than Reference- Equal to Reference0 Better than Reference +

11/01/05Wave Energy Power Generator6 Concept Groups (1a & 1b) Concept Group 1a Reel, Mech. Rectifier, Reduction Device, and Rotary Generator Reference Concept Group 1b Device integrated into buoy

11/01/05Wave Energy Power Generator7 Concept Screening

11/01/05Wave Energy Power Generator8 Concept Groups (2 & 3) Concept Group 2 Crank, Reduction Device, and Rotary Generator Concept Group 3 Piston and Direct Drive Linear Generator

11/01/05Wave Energy Power Generator9 Concept Screening

11/01/05Wave Energy Power Generator10 Concept Groups (4 & 5) Concept Group 4a&b Piston, Fluid, System of Valves, Turbine, and Rotary Generator 4a – Closed Turbine 4b – Open Turbine Concept Group 5 Air Camber, Oscillating Air, Turbine, and Rotary Generator

11/01/05Wave Energy Power Generator11 Concept Screening

11/01/05Wave Energy Power Generator12 Concept Scoring Relative PerformanceRating Much Worse than Reference1 Worse than Reference2 Equal to Reference3 Better than Reference4 Much better than Reference5

11/01/05Wave Energy Power Generator13 Final Design Selection Spring-Reel Buoy Design Scored best in top 3 needs –Cost Effectiveness –Power Output –Maintenance

11/01/05Wave Energy Power Generator14 Two Possible Design Location: 1.Hudson River 2.Raritan Bay (Coney Island) Wave Data Analysis 1 2

11/01/05Wave Energy Power Generator15 Wave Heights Over A Period of 8 days Period (seconds) Wave Heights (inches) Hudson River Data Histogram of Wave Periods During Typical Hours Period (seconds) Frequency (No of Wave Occurrence) Mean height is about 6 inches Maximum is around 20 inches Minimum is around 1 inch Mostly ferry-generated waves Mean Period is about 2~3 sec Maximum, 10 sec Minimum, 1 sec Majority of data falls between 1~6 seconds Wave Height Wave Period

11/01/05Wave Energy Power Generator16 Raritan Bay Data Wave Height Wave Period Hs = 4.0 * sqrt(m0) Mean Height, 12.2 inches Maximum, 81.5 inches Minimum, 1.1 inches 95% C.L.: 3.94~ % C.L.: 2.76~43.30 Period of the significant waves. Mean Period, 7.14 sec Maximum, 19 sec Minimum, 2.6 sec 95% C.L.: 3.1~ % C.L.: 2.9~14.2

11/01/05Wave Energy Power Generator17 Mathematical Model & Simulation Three major design segments relate to several system models Capturing / following wave motion model developed In the process of developing mechanical system & electrical system models Linear to rotary oscillation Oscillatory to Unidirectional Flywheel & Inverted Reduction Wave Linear Oscillation Rotary Oscillation Unidirectional Rotation Unconditioned Electrical Power Higher Speed Rotation Electrical Conditioning Conditioned Electrical Power Motion Capturing Device Wave Motion Mechanical Motion Electrical Energy Generator/ Alternator Capture the wave motion Electricity Generating Device Motion Conversion Device(s) Flow Chart of Wave Energy Generator System Model for Simulation

11/01/05Wave Energy Power Generator18 Assumptions: 1. Wavelengths of waves are larger than buoy diameter 2. Spring coefficient is constant 3. Cable always remains tight 4. Generating force is a quadratic function of speed. 5. Damping/drag force similar to an object moving in a fluid. y w y’ w y’’ w y b y’ b y’’ b FbFb W F gen F spr Arbitrary reference for y w and y b F drag A buoy Water Line Wave Motion Model Force of Buoyancy, F b Force of Spring, F spr. Force from Generator, F gen Damping/Drag Force, F drag0 Governing Equations

11/01/05Wave Energy Power Generator19 Wave Motion Simulation Compare Sinusoidal wave input to buoy displacement output Model Showed Overall weight had little effect Radius of device & reel spring constant had a greater affect on output time, sec Wave height, inches time, sec Buoy displacement, inches

11/01/05Wave Energy Power Generator20 PRODUCT ARCHITECTURE Control Reel Control Mechanism Reel Convert linear motion into two way rotational motion Enclose Device Waterproof Device Casing Chassis Provide Structural Support Hold Device Store Batteries Harness wave Energy Buoy Rectifier Rectify Motion into unidirectional rotation Flow of Force Flow of signal or Data Flow of Energy Gear Box Speed up rotation of shaft Rotary Generator Convert Kinetic Energy into Electrical Energy Charge Batteries Anchored cable Secure buoy position

11/01/05Wave Energy Power Generator21 GEOMETRIC LAYOUT Anchor Casing Cable Buoy Gear Box Rectifier Batteries Reel Rotary Generator

11/01/05Wave Energy Power Generator22 INCIDENTAL INTERACTION Casing Chassis Buoy Rectifier Reel Gear BoxRotary Generator Anchored cable Vibration Vibration, coupling Thermal Expansion Vibration, shaft Vibration, coupling Styling Friction Sealing Control Torque, RPM

11/01/05Wave Energy Power Generator23 System Integration: Requirements Functional Requirements: 1.The device shall charge 12V batteries. 2.The device shall be able to withstand 1 meter waves. 3.The device shall be able to produce at least 100 Watts at average wave conditions. Non-functional Requirements: 1.The total weight of the device shall be under 200 lbs. 2.The center of gravity shall be at the center of the buoy. Technical Performance Metrics: 1.Total efficiency of the device (%) 2.Total weight of the device (lbs) 3.The location of center of gravity from bottom center of buoy (inches) 4.Total number of moving parts (number)

11/01/05Wave Energy Power Generator24 Reel Design Considerations The length of maximum cable payout will be determined by site conditions. The spring must be strong enough for high waves, but not too strong to kill the small waves. An oscillating guide may be used to line the cable up. Reel with a guide even out the cable Reel Diameter Large Less sensitive to radius change Larger inertia More need for gearing up Small Sensitive to radius change Less inertia Less need for gearing up vs.

11/01/05Wave Energy Power Generator25 What it DoesHow It Works Unidirectional Clutch Bearings Simple gearing mechanism utilizing one-way clutch bearings Mechanical Rectifier Design Input Output Engages w/ input of CCW Engages w/ input of CW

11/01/05Wave Energy Power Generator26 Mechanical Rectifier CAD Model Isometric View Exploded Top View

11/01/05Wave Energy Power Generator27 Gearbox Concepts & Considerations Planetary Gearing Compact, highly efficient and reliable Parallel Shaft Gearing Low part count Worm Gears High ratio, compact, very low efficiency Belt Inexpensive, low reliability Optimal gear ratio dependent on generator RPM range Need for a Flywheel: Will allow generator to remain around the operational range where the efficiency is maximum.

11/01/05Wave Energy Power Generator28 Generator/Alternator Major Concerns: Operate at high RPM Low efficiency at low speeds High gearing ratio required Lower operational RPM is preferred Alternator is lighter, cheaper and more efficient than generators. 600-W Alternator Alternator Efficiency vs. RPM

11/01/05Wave Energy Power Generator29 Project Budget

11/01/05Wave Energy Power Generator30 Gantt Chart

11/01/05Wave Energy Power Generator31 Conclusion What’s Next –Continue Detailed System Design –Assembly (CAD) Drawing & FEM Analysis –Final Weight and Cost Estimation –Final Report and Presentation Team is currently meeting project schedule objective Prepare for ME 424

11/01/05Wave Energy Power Generator32 Questions or Comments?