Senior Design Crappy Design

8/8/2019 Senior Design Crappy Design

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Honor Code:

on Dynamic Ocean Wave MotionI.

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I have neither given nor received unauthorized assistance on this graded report.


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Abstract:Energy Generation Based on Dynamic Ocean Wave Motion

Methods of green energy generation from the motion of waves in the ocean are explored.A buoy is de signed ttranslate the vertica l motion of a wave to a continuous rotating shaft andutilize/a gen era tor to harness electrical energy . A prototype is developed in order to model thecon cept of design. The buoy theoretically will produce 1.5 kW assuming idea l wave cond itions .The estimated costs show s the buoy as a competitive energy source compared to so lar and windpower. With fu rther research and design improvements, the buoy has potential to be an energyharnessing method in the fu ture .V

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Table of Contents:

Introduction 4Work Plan 5Theoretical Background 6Analysis and Sample Calculations 14

Prototype Development 22Design of Experiments and Laboratory Tests 30Environmental Considerations 33Social Considerations 35Safety 35Cost Analysis 36Final Design 40Bibliography 51

Conclusions 52Appendix 53

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Introduction:

Finding alternative renewable energy sources is one of the biggest challenge s humanbeings face today. As oil and coal are dep leting , environmental concerns are increas ing ,1he needfor ending the dependency on fossil fuel has become a priority for many governments of theworld. One of the main obstacles that the developments of alternative sources have been facing ishe cos t ef fectiveness. Cur rently , green energy sou rces are not near ly as cost ef fective as foss ilfuel alterna tives.This project sets out to design a buoy system that will generate renewable electric power

from the ve rtical motion of te waves. A mechanism is developed to harness energy from thewaves and translates it into elec tric power that can be utilized in daily life app lica tions.This design is intended to create an al ternative, cheap and reliable source of energy that

will reduce the dependency on fossil fuel and be used both commercially and pr ivately. It isexpected to produce a significant output that could be utilized in various applications and iscompet itive with other green power methods such as wind and so lar power.The system cons ists of a steel buoy with a pulley-shaft system mounted inside it. The

buoy is floating in water and the pulley-shaft system is anchored with a counter mass. Thepulley-shaft assembly is connected to an electric generator. The waves push the buoy up anddown and cause the shaft to sp in which translates the spinning motion to the electric generato r .frjit-at outputs useab le energy.After the system was theoretically tested using a scaled model, it stoave met the

de sired goals.

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Work Plan:r

Preliminary Research

Task Start Completion Hours Members MethodThurs,1/31 Thurs, 2/11 60 All

Internet,LibraryResourcesThu rs,Preliminary Design #1 2/4 Thurs, 2/1 1 20

Thurs,Preliminary Design #2 2/4 Thurs, 2/11 20Budget Request Mon, 2/8 Tues, 2/16 2

Dynamic Forces, Stresses,Calculations Mon, 2/8 Thurs, 4/8 85Develop Matlab Code Mon, 2/8 Thurs, 3/11 15Wave Frequencies in differentlocations Mon, 2/8 Thurs, 2/18 6Research Mechanical EnergyConversion to Electrical Mon, 2/8 Thurs, 3/11 20

V Tues,Design of Mechanical Parts 2/16 Thurs, 3/11 25Thurs,

Energy Storage 2/18 Thurs, 2/25 4Tues,

Project Accounting 2/16 Tues, 4/20 4Thurs,CAD Drawing 2/18 Thurs, 4/15 45

Research and Purchasing Parts Mon, 3/ 1 Mon, 4/19 40Experimental Apparatus Thurs,Construction 4/1 Mon, 4/19 20

Thurs,Prototype Construction 3/11 Tues, 4/13 60301515

Tues,Sealing Buoy from water 2/16 Mon, 4/19 15

Four PaddlesPulley System

Shear,Normal,.)NewtonsLawsMatlab

NOAAMagnets andwire coi lsPulley, shaft,bearings,shell, cable, -flywheelResearchMethods

CATIA

j

Final TestinaTues,4/13 Mon. 4/19

VacuumHosing,sealants20Thurs,Project Report 4/8 Mon, 4/19 80 All MS WordTues,Meetings with Advisor 1/26 Wed, 4/21 30 All

Thurs, MSFinal Presentation 4/15 Thurs, 4/21 20 All PowerpointTotal 651

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Theoretical Background:

The system is designed to harness wave energy. The buoy moves up and down due to theforces from the waves. As the buoy is forced up, a cable that has one end attached to the bottomof the body of the water will exert a pulling force which will cause the pulley inside the buoy tospin. The other end of the cable is attached to a free hanging mass.

The coaster gear will be fitted into a specially designed pulley so the pulley will onlyexert a force in one direction around the shaft. This is done because the coaster gear will onlyengage once the pulley has a velocity greater than the shaft. This wil l allow the system to bemore efficient by keeping the shaft constantly moving in one direc tion . By adding a flywheel tothe shaft , inertia will resist deceleration when a force is not exerted on the shaft by the pulley. Toharness the energy of the spinning shaft, a generator is attached to one end of the shaft. Thegenerator will spin a permanent magnet between a series of coils, and the magnetic fields willinduce a current through the coils.

First, the free body diagram of the hanging mass is analyzed as shown in Figure 1. Thereare three forces that act on the hanging mass; weight, buoyancy and cable tension. By applyingNewtons 2 law in the y-direction, eq. 1.1 is derived, where mm is the mass of the free hangingmass, Ym is the acceleration of the hanging mass, and Fb is the buoyancy force. Neglectingpressure difference, the buoyancy force is Fb Vpg where Vm is the volume submerged, Pwis the density of water, and g is gravity. f) \ fr

By controlling the volume (Vm) and hang g mass (mm) to meet ou r designthe force of the cable is the only unknown in q. 1.2 so the buoyancy

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F = ma (eq. 1.1)

mg + Fb,m + Fm = mmYm (eq . 1 .2)Fm = mmYm Vpg + mg (eq. 1.3)

Fm = mmYm + mg (i (eq. 1.4)

Figure 1 FBD of Hanging Mass

Next, the assumption that the cable does not stretch or slip on the pulley is malThismeans that at the point where the cable contacts the pulley, both the pulley and cable wil l have

- JW3Jae same veloci/The forces that the cable exerts on the mass and the force the cable exerts onthe pulley will be equal. With this, and assuming the no-stretch condition, the following,pk

- W1 relationships can be formed, eq. 2.1-2.5. Using the no slip and no stretch condition, therelationship between the displacement of the buoy and the hanging mass is described in Figure 2

Sand eq. 2.6-2.8. The displacement of the hanging mass is twice as much as the buoy because the

(eq.2.1)(eq. 2.2)(eq. 2.3)(eq. 2.4)(eq. 2.5)(eq. 2.6)(eq. 2.7)(eq. 2.8)

YiYi=3

= r9Yrn = 2iYm = 2Ym = 2

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=

Figure 2 No slip and no stretch condition

The sha ft inside of the buoy is attached to the base of the buoy by two pillow blockbearings. The first bearing is a thrust bearing on the f ree body diagram is point A which is foundin Figure 3, and has x-, y- and z- components. The second bearing is a normal bearing and has xand y- components. The pulley is attached in the middle of the shaft in order to center the forcesproduced by the cable. e pulley, two forces are produced, one by the end of the cable

attached to the grou (Tg) a d the other attached to the counterweig (Tm). he pulley also hasa mass that will prod e a eight force (mpg). The center point of the mass of the shaft (msg) isalso concentrated at this point. On the lef t end of the shaft, there is a fly wheel attached that has amass which produces a weight force (mfg).

The la st fo rce is a moment from the generato (iIo) hich is located on the right end ofthe buoy. The mass of the generator is no t located on the s aft because the generator will beattached to the base of the buoy. Also, no reaction forces from the shaft to the generator exist,except for the moment because in order to minimize the stresses on the generator, the forcesshould equal zero at the contact point.

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By neglecting motion of the buoy in the horizontal plane, the y- and z-direction, the sumof the sn-.4e.forces in the y- and z-direction is set equal to zero, eq. 3.1, 4.1. The sum of theforces in the x-direction is set equal to the mass of the shaft, pulley and flywheel multiplied bythe acceleration in the x-direction. Next, the sum of the moments about the x-axis, at point A isset to zero since the moments are balanced evenly, eq. 5.1. Finally, the sum of the momentsabout the z-axis, at point A are se t equal to the angular acceleration multiplied by the inertia, eq.7.1, where inertia for a cylinder is I = 2

Figure 3 FBD of shaft assembly

Shaft

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(eq. 3 .1)

(eq. 4.1)(eq. 4.2)(eq. 5.1)

A=O

s,y=0

=00= 0

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F = (m f + m + m)yiAX+BX(mf+mP+mS)

)..MAZ = (eq. 7.1)MG + (Tm = 2 (eq . 7 .2)

The last free body diagram is the base of the buoy that is found in Figure 4. There areforces from the two bearings, the buoyancy, the weight of the buoy, the generator, and themoment f rom the generator. The sum of the forces in the y-direction is equal to the mass of thebuoy and generator multiplied by the acceleration, eq. 8.1. The sum of the moments about the xaxis at point A will equal zero because the system needs to be balanced. The moment producedfrom the generator on the buoy has no t been accounted for bu t will be later in the analysis.

1 J,Bmg mgTTTT1 tTtTtTT

Figure 4 FBD of buoy base

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BuoyF,,x = (m,, + mG)y2 (eq. 8.1)

Fb,b (A + B) (mb + m)(g = 0 (eq. 8.2)/ib = 0 (eq. 9.1)jI ( xF,b mbg) (x +x(B + m,,g) = 0 (eq. 9.2)

After all the free body diagrams have been analyzed, the system can be described withthe following four equations:

Ax+Bx(m+mp+ms)(gi)TgT=0 (eq.6.2)MG + (Tm = (mfrI+mPrPmsrs Os (eq . 7 .2)F,,,, (A + B) (m,, + mM)(g = 0 (eq. 8.2)xF,,,,, m,,g) (x +x(B + m,,g) = 0 (eq. 9.2)

The masses, radii, and distance across the shaft are determined based on designspecifications. Using eq. 2.1, Tm Fm where Fm is known. With this, there are four equations withfive unknowns. To solve this system of equations, one more equation is needed.

The solution is to determine the maximum buoyancy force produced by the waves.Waves produce force from the density of the water, and by the motion of the waves that willproduce an impact force that pushes the buoy. Since it is impossible to calculate the force fromthe motion of the wave, the fo rce will be used as a safety factor. The buoyancy force from thedensity of the water can be found by eq. 10.1, where this will be the maximum buoyancy forcethe waves can produce so if the buoy produces an overall net force greater than th is , the buoywill become submerged under the water.

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The system of four equations has four unknowns, so the system of equations is solved inthe order below, eq. 11.1-11.4.

F,,,,, = (eq. 10.1)B xFb,bmbg)(xx(mbg) -X (xx eq.A = Fb,b B (mb + mG)(g (eq. 11.2)Tg =A +B (mf +m +ms)(g Y1Tm (eq. 11.3)MG = (mr1+mrmsrs Os (Tm Tg)rp (eq. Ii .4)With th e speed and the maximum moment the generator can produce, the maximum

power is solved for by eq . 12.1. By assuming the speed of the pulley follows a perfect sine wavethe power produced would also follow a perfect sine wave. The average power in a half period ofa sine wave is related to the max power by1avg = Ppeak/V and since the system only harnessespower as the pulley spins in one direction so power is described in eq. 13.1.

peak = (eq. 12.1)p _Ppeak/ 131vg

/22 eq.

With the power produced by the shaft, the electrical energy can be foun the efficiencyof the generator is known. A typical generator usually has an efficiency aro 90% s thepower produced can be calculated by:

p _JPpeak/ 141roduced /2I eq.

With all the forces on th e shaft, a stress analysis is performed. When at rest, a substantial

By modeling it this way,Matlab program which is

be assumed. With a locked system assumption, a


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torque stresses along the shaft and around each cross sectional area of the beam. Then with theuse of Mohr s circle, the maximum principle and shear stress are found. With these stresses, theradius of the shaft is found based on the strength of steel. With the tension on the cable, therequired thickness of the steel cable is found.

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Analysis and Calculations:Givens:

Pw = 1000 kg/rn Ps= 7860 kg/rnrn=40kg m=40kg rnb=5Okg

m=2kg rnf=2Okg m=2kg= 0.05 m rf = 0.08 m = 0.15 rn

x = 0.15 m x = 0.10 rn x = 0.10 m x = 0.15 rnsub =.262m

Speed of buoy:

The up and down motion of the waves at Cape Elizabeth which is 45 NM northwest of AberdeenWashington (47.34N 124.75W) is analyzed using a chart of the average height (A) and period(T) at different times throughout the day found in the Appendix.

From Chart:

Aavg = 11 ft = 3.33 rn & Tavg = 13 sec

Calculate velocity and acceleration of buoy:

2irfrequency = cv = -- = 0.4833 sec

S. =cvA = 5.32rn/s

= co = 2.57 rn/s

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Calculate velocity and acceleration ofmass using the no stretch/slip condition:

3m = 23> = 10.64 rn/s

Yrn = 2 = 5.14 rn/sCalculate angular velocity and angular acceleration of shaft:

rad8 =Yi/r = 35.5= 339rpm

O /r = 17.lrad/s

Calculate tension of cable attached to counterweight:

Tm = Fm = rnrnyrn+rnmg(i ) = 548.1NCalculate buoyancy force on buoy:

Fb,b 1subPwg = 2570 NCalculate force on the normal bearing in the x-direction:

B = x2(Fb,b mbg) (x +x(mg) = 341.4 N(x + x)Calculate force on the thrust bearing in the x-direction:

A = Fb,b B (mb + mG)(g = 1577.ON

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Calculate tension of the cable attached to the ground:

TgAx+Bx(m+mp+ms)(gi)_Tm 1196.5N

Calculate the max moment the generator can produce:

fmfr/ + m r + m ri\. .MGj 2 )6s+(7q_Tm)rp=98.8N_m

Calculate the peak power that can be produced:

MG * 0peak 7.0375 = 4759 W

Calculate the electrical energy produced:

7peak / 1514.4 Wproduced /2 I =i)Using Matlab, the max shear and principle stress can be found for a givenradius:

Radius of aft = 0.01 m

Shear Str ss = 9 . MPa

Principle tress = 155.0 MPa

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304 Stainless Steel has a Max Shear and Principle Stress of 186 MPa and 500MPa so the safety factor can be found. The radius of the shaft was adjusteduntil the Safety factor of 2 was achieved.

186MPaS.F.Shear= =3.29OMPa500MpaS.F.PrLncLple = 155MPa = 2.1

The generator in the buoy will place a moment on the buoy which will cause thebuoy to tilt. The angle of the tilt needs to be checked to make sure it will not affect thebuoys performance. To perform a quick check on the tilt, the buoywas split into twosections, the left and right side of the buoy shown in Figure 5. The assumption thatbuoyancy force of each section of the buoy will occur on their respective center points ismade. The moment caused by the two buoyancy forces about the center of the buoy isfound. By comparing the moment of the buoyancy force to the moment of the generatorwhich is equal, the difference in heights at the center points of each section is found. Withthis distance and the distance between the center points, a slope is found.

4d4

Figure 5 Tilt analysis

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MG=Fb=d*Fd*Fl=dPwg(f)(h)where h is the change in hieght & d

MGh= =0609firrdpg

slope = tan h/() = 8.166

The generator will cause the buoy to tilt only 8.17 which in reality will be lessbecause as the buoy tilts the volume will increase on the one section which will cause morebuoyancy force on that particular section which is unaccounted for in our calculations. Thisslope was satisfactory because the buoy can be naturally weighted to one side before themotion of the generator so when the generator starts to move the buoy will only tilt 4.083in either direction.

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The preliminary theoretical design starts with the thought of a buoy moving up and downa shaft from the motion of waves. A shaft is mounted to the floor of a river and the buoy isshaped as a ring and would encompass the shaft. A magnet is then mounted to th e shaft n ear thetop of the water. A copper coil is mounted inside of the buoy and as the buoy moves up anddown from the motion of the river, the copper coil will move around the magnet and induce acurrent.

There were many flaws with this design. Mounting a shaft to the floor of a river would beextremely expensive and difficult to perform. Waterproofing this system would be very complexand the vertical distance traveled by the buoy in a river was found to be insufficient to achievedesired output results.

The next theoretical design changed from harnessing vertical wave motion to harnessingrocking motion of the buoy . The buoy is tethered to the bottom of the river floor by a cable. Fourarms extend ou t of the buoy and into the water. These arms wil l move up and down with themotion of the waves and connect to a piston that will push a magnet through a copper coil,inducing current. The four arms could also be used to spin a gear with a magnet attached thatwould run through a copper coil . The rocking motion was found to be insufficient to provide thepower desired.

The f inal design incorporated the vertical motion ofwaves in the ocean because theoceans waves are much larger and can create a larger distance the buoy can travel . With largerwaves and distances, larger forces and accelerations can be harnessed by the buoy, creating alarger output of power. The motion of a magnet passing through a copper coil is easily harnessed

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with the use of a generator. The generator is more practical, cost effective, and easier to producethan developing a separate apparatus that spins a magnet within a coil. A shaft coupled to thegenerator will sp in from the movement of a belt. Each end of the belt will run through a separatehole in the bottom of the buoy while the cable is engaged in a clutch pulley attached to the shaftshown in Figure 6. A corrugated hose is flanged and sealed on each of the two holes in thebottom of the buoy; the belt runs over the pulley clutch and inside of each corrugated hose. Thebottom of the corrugated hose is then capped and sea led to keep the inside of the buoy and beltwaterproof. A cable is then connected to a cap and runs to an anchor at the bottom of the ocean, a

separate cable is connected to the other cap and a counterweight is attached. As the buoy risesfrom a wave, the belt will run over the coaster pulley and engage the shaft , forcing it to sp in , andtranslating mechanical energy into electrical energy from the generator. A s th e cab le runs overthe coaster pulley, the belt will pull on the corrugated tubing attached to the anchor, forcing it toelongate, while forcing the tubing attached to the counterweight to rise and contract.

Figure 6 Shaft assembly with chain running over coaster gear

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The shaft will be mounted with two bearings for support and a flywheel to add inertia tothe spinning shaft to prevent deceleration. As the wave starts a downward motion, the coasterpulley will disengage and spin freely until the wave starts its upward motion. During thedownward motion, the inertia of the flywheel will keep the shaft spinning so continuous workcan be achieved. Once the upward motion starts again, a cycle is completed and will repeat.

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Prototype Development:

The preliminary design included th e use of a shaft mounted in two pillow block bearingswith a flywheel on one end of the shaft and a generator on the other end as shown in Figure 7.The generator and the pillow block bearings are mounted to the platform, where the platform ismounted to th e bottom interior of the buoy as seen in Figure 8. A belt runs over and engages theshaft with the use of a clutch or gear. The two ends of the belt will go through two separate holesin the bottom of the interior of the buoy. One end of the belt would be fixed to the sea floor andthe other would have a counterweight attached. The belt and holes would be sealed to keep thesystem waterproof.

Figure 7 - Shaft assembly (from left to right) with flywheel, pillow block bearing, coaster gear,pillow block bearing, and generator

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Figure 8 - Platform mount in bottom of buoy

The initial development of the prototype started with research of a one-way clutch and acoaster gear. Research is performed to find a suitable solution that will allow the shaft to engagein only one direction. A one-way roller bearing is purchased which would allow a belt to runover the entire bearing and engage the shaft while spinning in one direction and spin freely in theopposite direction. This bearing turned ou t to be too small and could not endure the torque thesystem would create. A coaster gear found at a bicycle shop fixes this problem and the u se of achain spins the shaft effectively.

The coaster gear is then measured to find a shaft and bearings to fit. The gear has an innerdiameter of 15mm and bearings could not be found to match. A 5/8 shaft, bearings, andflywheel were purchased and the inner diameter of the gea r is drilled to fit the shaft and bearings.A chain was purchased that fit the oute r teeth of the coaster gear. Electric motors and generatorswere then researched bu t a suitably geared motor for an rpm range of approximately 60 were

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hard to find. A hand crank generator was purchased, modified, and tested to determine its output.The generator allows the output to be shown through a light bulb or leads can be connected to avoltmeter for demonstration purposes which can be seen in Figure 9(a). The hand crank on thegenerator is removed and a shaft is exposed with a hole perpendicular to the length of the shaftshown in Figure 9(b).

A hole is then drilled in to the 5/8 shaft , parallel to its length, which will allow the shaftf rom the generator to slide inside of the 5/8 shaft shown in Figure 10(a). A hole is then drillednormal to the length of the 5/8 shaft , as shown in Figure 10(b), so that a cotter pin can slide intothe 5/8 shaft, into the generator shaft, back into the 5/8 shaft , and ou t the other side. This f ixesthe two shafts together and allows them to spin as one .

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Figure 9(a) Hand crank generator with light bulb and leads

Figure 9(b) Hand crank generator with handle removed, exposing shaft


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Figure 10(a) Hole drilled normal to each shaft

Figure 10(b) Hole drilled in parallel in 5/8 shaft to fit the generators shaft

The expected length from the end of the motor to the end of the flywheel is 16 and asuitable structure is then needed to fit the shaft assembly and have enough buoyant force to stayafloat. Various solutions were contemplated bu t a problem continued to be the diameter of thecontainer. To solve this, the length of the shaft assembly is reduced in length near its minimum

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of 10.5, and a 5-gallon painters bucket is used as the structure. An inexpensive structureallowed for cost effective testing and multiple structures are purchased to allow room for error inassembly.

Two holes were drilled in the bottom of the 5-gallon painter bucket so the chain can runover the coaster gear with an end of the chain going through each hole. Initially, corrugatedtubing would be sealed to the bottom of the 5-gallon painter bucket, engulf the chain , and besealed at th e end of the chain to keep the system waterproof. The corrugated tubing ended upbeing too stiff and would not elongate and compress upon itself. The elongation and compressionis essential because as the buoy rises and lowers, the chain will be attached at an end of thetubing, where the chain and tubing will move in the vertical direction. This allowed us toinvestigate surgical latex tubing bu t problems mounting the chain and sealing the tubing off werea problem.

Vacuum tubing is tested and the elongation and compression work well. Each end of thevacuum tubing has a plastic cap attachment that can thread onto the vacuum tubing. The caps arethen attached to the bottom of the 5-gallon painters bucket with epoxy and sealant shown inFigure 11. The caps on the other end of the vacuum tubing are attached to PVC fittings with theuse of epoxy and sealant shown in Figures 12(a),(b). The PVC fitting is made from two femaleconnectors that screw onto each side of the male cap, making a seal with a cap in the middle oftwo female connectors as seen in Figure 13. A cross brace is drilled through the side of a femaleconnector and a rope is attached to the cross brace. Each rope will have a weight, one being ananchor and the other a counterweight. In Figure 14, the exterior of the buoy is shown but doesno t have a rope connecting the PVC fittings to an anchor or counterweight.

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Figure 11 - Chain running through threaded plastic caps mounted to a 5-gallon painters bucket

Figure 12(a) Vacuum hose separated from PVC fitting and plastic cap

Figure 12(b) Vacuum hose threaded into plastic cap27


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Figure 13 - Two female PVC connectors threaded onto a male cap

Figure 14 - Exterior of buoy

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T he sy ste m w ou ld be manufactured on an assembly line. The design implemented,accounted for practical assembly on common p ar ts . T h e parts would be machined or createdfrom a supplier. The manufactured assembly of the theoretical design would start with having th eshaft coupled to the generator. A pillow block thrust bearing, coaster pulley, an d a pillow blockbearing slides o nto th e sha ft a nd is secured with setscrews. Th e flywheel would be attached toth e e nd of the shaft with th e us e of a setscrew. Se t screws allow for easier assembly an dmaintenance.

The system would continue to be manufactured by setting t he sha ft assembly onto thebase of th e buoy. Bolts will mount the pillow block bearings an d generator to a raised platformo n the base of the buoy. Th e platform w ill h av e threaded holes for easy alignment of flanges onthe generator an d bearings. Fittings will be attached to the ends of the corrugated tubing and willthread an d seal to th e bottom of the buoy. T he belt will then run over the coaster pulley an dthrough each side of corrugated tubing. Th e other ends of tubing will have fittings that seal tok ee p t he system waterproof. An eyebolt will attach i nt o t he fitting and a cable w ill attach to acounterweight an d an anchor on either side. The buoy an d platform will be made out of steel.Th e bottom portion with th e shaft assembly w ill b e welded with the top half an d will completeth e buoy assembly.

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Design of Experiments and Laboratory Tests:

An experiment has been designed on the energy harnessing buoy to attempt to simulate

the effect of a wave without a body of water. The experimental apparatus consists of a 42-gallongarbage can, a 5-gallon painters bucket, 4 drain tile hose, dra in t ile adaptors, and varioussealants and epoxies. The bottom of the garbage can and the 5-gallon painters bucket is mountedwith a drain tile adaptor with the use of epoxy and sealant. The 5-gallon painters bucketmounted to the drain t ile hose is shown in Figure 15. The drain tile adaptors are each fit ted to anend of the drain tile hose and sealed. Giving an assembly of a garbage can and a 5-gallonpainters bucket connected with a drain ti le . The apparatus is then filled with water so that eachgarbage can is approximately half full. The buoy is anchored to the bottom of the garbage can onone side of the chain and a counterweight is attached to the other side of the chain. The 5-gallonpainters bucket is lifted and gravity would induce equilibrium and force the water into thegarbage can containing the buoy. This would raise the water level in the garbage can and thedisplacement ofwater would force the buoy to rise, spinning the coaster gea r and shaft, creatingcurrent in the hand crank generator.

Figure 15 - 5-gallon painters bucket mounted to drain ti le hose30


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This experiment did not displace enough water to force th e buoy to rise an d the idea ofusing three 5-gallon painters buckets evolved but was no t used because numerous seals neededto be created for each bucket used. The experiment uses tw o garbage cans connected in a similarfashion using drain tile adaptors bu t fails because the seals are no t able to hold o n the forces fromthe standing water. To try to solve this problem, the drain tile adaptors are removed from theexperimental design, an d th e drain t ile hose will seal into the garbage cans directly with epoxyan d sealant as shown in Figure 16.

Figure 16 - Garbage cans connected with drain tile hose

The experiment runs with the buoy floating on the water with the anchor an dcounterweight underwater. Th e garbage ca n without th e buoy is raised approximately three feetan d water is forced in to th e garbage ca n with th e b uo y. T he buoy rises an d the shaft is engagedbu t t he l ig ht does not turn on. Th e garbage ca n is lowered an d water drains ou t of the garbagecan holding the buoy, forcing th e buoy to fall. This process is repeated but there is not enoughwa te r f low to raise the water level high enough to create enough power to turn on th e light bulb.

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Minimum Revolutions to light bulb0.5 rotation/second30 rpm

Experimental Wave Data

0.75 ft4 seconds

0.1875 ft/sec0.523333 circumference of gear (ft)0.35828 rotations/sec

21.49682 rpmExperimental Requirements for bulb to light

1.046667 ft4 seconds

0.261667 ft/sec0.523333 circumference of gear (ft)

Table 1: Experimental wave data and wave requirements.

The required velocity for the buoy to raise and power the light bulb is 0.26 ft/sec whilethe experiment only produced a velocity of 0.19 ft/sec as shown in Table 1. The difference invelocity could be solved by connecting another drain t ile hose between the two garbage cans oradding another garbage can, which would allow two garbage cans to be lifted, forcing morewater into the testing garbage can. The garbage can testing apparatus has problems with the sea lsconnecting the drain tile hose. When the garbage can is lifted, a large force transfers between thegarbage cans and a torque is applied to the hose connection. This caused the seals to slowlydegrade and eventually fai l entirely. This could be changed by using flanges to connect the draintile hose to the garbage cans. Also, sealing the vacuum hose to the cap connections has problems.Water would enter the vacuum tubing that contains the chain from the threading in the plasticcaps. The use of flanges to connect the vacuum hose to the plastic caps could prevent thisproblem.

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Environmental Aspects:

Alone, a single buoy does not have much of an impact on the environment. However,environmental concerns arise from a buoy system using multiple buoys in array formation forlarge scale power generation. In this case, consideration on the impact and possible disruption onthe ecosystem in which the buoy is placed must be considered.

The location of the buoy system poses some environmental concerns if it placed close tothe shoreline. Minor disruption of local ocean wildlife will occur during the installation of thearray. Other than the initial installation and routine maintenance, the system will be completelyfree of fossil fuel dependency. If failure occurs in the system, other than the debris that would bescattered across the landscape, the system poses little risk of contaminating the environment. Allof the components pose little harm to the environment if failure occurs. The highest risk tocontamination would arise from the bearings in the pulley and pillow blocks as well as thegenerator from possible leakage of oils and lubricants.

A recent article in the Block Island Times reports that the transmission of electricitythrough electric cables connected to offshore wind turbine farms can have a maj or impact on themigration patterns ofmany types of sea faring wildlife. In particular lobsters, sharks, sea ls andcrabs are species which can be found near the location which is designed to house the buoysystem. This may be a cause for concern as those creatures use the earths magnetic field inmigration patterns. In addition to migration patterns, sharks use magnetism to hunt for prey. Thearticle notes that further research will need to be conducted to determine whether sea life,

How dofish react to wind farms and cables? Steve Scos --April12, 2010

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especially those most affected by the cables would be able to adapt to the magnetic fieldscreated.

In addition to the magnetic fields created, the article also delves in to the effect of drivingpiles in to the seabed for the wind turbines. This is less of a concern for this system as the buoysdo not need as severe of anchoring as a wind turbine.

Another study 2 was conducted to determine whether magnetic fields could influence thedirection of travel of particular fish by testing whether the fish were attracted to magnets, bothnorth and south facing which were attached to fyke nets in addition to a control net in which nomagnets were placed. The conclusions of the study indicate that, The magnet-rigged fyke netswere found to catch by 70-90% more fish (depending on the magnet pole location) than controltraps, rigged with magnet dummies, did.

/2 Effects OfMagnetic Field On The Direction OfFish Movement Under Natural ConditioneDepartment of Fish Anatomy and Embryology, Agricultural University ofSzczecinKrzysztofFormicki, Adam Tahski, Aleksander Winnickihttp://www.ursi.org/Proceedings/ProcGA02/papers/p0842.pdf

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Cost Analysis:

A significant portion of the cost is expected to be spen t in installation as the system willbe installed in the ocean. Installation costs w ill include the cost of transportation, tools,equipment, and labor. Annual operating and maintenance costs are estimated. The lifeexpectancy of the electric generator is typically around 8 years, and based on the 15 yearsestimated life expectancy of the system; the generator will have to be replaced at least once. Theoverall price of energy does not take into consideration the losses in transmitting the power to theshore where it can be utilized. Such losses are expected to be high and will increase the cost ofenergy. The cost breakdown of manufacturing and installation of one unit for the buoy system isestimated in the following table:

Part Price (US $)Electric Generator 800*Shaft 100Bearings 102Pulley Clutch 95Belt 500Body 1,000Sealing System 700Anchor 70Miscellaneous 300Total 3,667

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Installation 5,500Operating and Maintenance (Annual Cost) 400Table 2: Cost Breakdown.

Based on the energy output calculation, the generator will produce an output ofapproximately 1.5 kW. In order to test the cost effectiveness of the project, the power generationis compared to two of the main green alternative energy resources, wind and solar. Thecomparison takes into consideration several factors; generated output, system cost, installationcost, maintenance cost, efficiency, life expectancy and power cost per hour. The following tablesummarizes the results of the comparison:

Buoy System Buoy System Wind Turbine Wind Turbine Solar Panel( I unit) (Farm 400 units) (Residential) (Commercial) (Commercial)

Output(kW) 1.5 600 1.5 600 1.5System Cost (US $) 3,667 1,393,460 7,000 800,000 12,000Installation Cost (US $) 5,500 240,000 Included Included IncludedMaintenance Cost! 400 32,000 140 16,000 50(Annual) (US $)Expectancy Life (Years) 15 15 30 30 20Efficiency (%) 75% 75% 18.0% 20.0% 13.2%Power Cost (cent!kWh) 10.16 3.574 15.78 4.059 37.48

Table 3: Summary of Comparison Results.

While most of the data used to f ind the above results is obtained from commercial sources, someof it is assumed based on industry standards. The comparison is established based on the

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quantities and their outputs. This comparison may not provide accurate results since data forefficiency and life expectancy are estimated.

The buoy system is first compared to a small residential wind turbine with an equivalentoutput to one unit buoy. Another comparison is conducted between a larger commercial windturbine with an output of 600 kW and a farm of 400 units of buoys that provide the same outputin order to test the cost effectiveness of building one unit compared to building a farm of buoys.

Secondly, a one unit buoy system is compared to a residential solar panel that is expectedto produce the same output and has the same life expectancy.

Under ideal conditions, one unit of the buoy system wil l have a lower power cost thanone unit of a small residential wind turbine or a residential solar power unit. Also, a farm of 400buoy units will have a slightly lower power cost compared to a large commercial wind turbine.The following charts show the details and the results of each comparison:

a. Buoy system vs. rdtIsnf1 1.5 kW wind turbine:, Buoy System Wind Turbine

Capital Cost (US $) 3,667 7,000Installation Cost (US $) 5,500 IncludedInitial Cost (US $) 9,167 7,000Life Expectancy (Years) 15 30Operating and Maintenance Cost (US $) 400 140Annual Cost (US $) 1,011 373Annual Energy Output (kW) 9,950 2,365CostperkWh(US$) 0.1016 0.1578

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b. Buoy system vs. residential solar panel:Buoy System Wind Turbine (Resid.)

Capital Cost (US $) 3,667 12,000Installation Cost (US $) 5,500 IncludedInitial Cost (US $) 9,167 12,000Life Expectancy (Years) 15 20Operating and Maintenance Cost (US $) 400 50AnnualCost(US$) 1,011 650Annual Energy Output (kW) 9,950 1,735Cost per kW h (US $) 0.1016 0.3748

c. Buoy farm vs. 600 kW commercial wind turbine:Buoy Farm Wind Turbine (Comm.)

Capital Cost (US $) 1,393,460 800,000Installation Cost (US $) 240,000 IncludedInitial Cost (US $) 1,633,460 800,000Life Expectancy (Years) 15 30Operating and Maintenance Cost (US $) 32,000 16,000Annual Cost (US $) 140,897 42,667Annual Energy Output (kW) 3,942,000 1,051,200Cost per kWh (US $) 0.0357 0.0406

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Final Design:

Figure 17 Shaft Assembly

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Figure 18 Buoy Housing with Assembly

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Figure 19 Buoy Housing with Assembly, Corrugated Tubing, and Counterweight

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Figure 20 Corrugated Tubing with Counterweight and Cable

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L1(0

C

Figure 21 - Inner Bearing

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0 0 C,

U,

j \-Je23.67

7934


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Tj (D

3 50

L m


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I

r

121

CD

oII i

o 61

152.4


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R245

94 C

5O .94

Figure 25 - Corrugated Tubing

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It)

200Figure 26 - Flywheel

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0

zL


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Bibliography:

Effects Of Magnetic Field On The Direction Of Fish Movement Under Natural Conditions.Department of Fish Anatomy and Embryology, Agricultural University of SzczecinKrzysztof Formicki, Adam Taski, AleksanderWinnickihttp ://www.ursi .org/Proceedings/ProcGAO2/papers/p0842.pdf

How do fish react to wind farms and cables? Steve Stycos -- April 12, 2010http://www.blockislandtimes.com/view/full_story/7020209/article-How-do-fish-react-towind-farms-and-cables-?instance=homenewsl st_right

The Economics of Wind Power. N.p., 2005. Web. 20 Apr 2010..

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Conclusions:

Investigation of energy generation from ocean wave motion shows that another greenenergy source ha s the opportunity to be harnessed. Th e goal in research an d development of abuoy to generate energy met an d exceeded th e proof of concept. Even though th e prototype wasunable to perform in the water simulated experiment, it does n ot m e an that it will no t w or k. T heperformance of th e buoy was poor du e to th e experimental apparatus. When th e buoy is tested byhand, results ar e much more desirable. This result shows that more research into wave energygeneration should continue.

Even though the cost of energy fr om th e buoy design is less expensive than that of windan d solar power, there are efficiency factors that are difficult to predict. Energy losses will com efrom an electrical grid to contain the energy an d come from sending the energy to the shore.T he se lo ss es w ill m o re than likely be la rg e a nd will significantly alter the price at which energyis produced. Even with these losses, wave motion energy is believed to be economical an dcompetitive to other forms of energy. Wind, sol ar , and wave power are all renewable, green, anddo not have a fuel cost.

Th e design is advantageous because it achieves continuous power from a constantrotation of a shaft . This design could be improved by making the system more efficient an dreliable by converting the downward motion of the buoy into rotational motion of th e shaft. Thiscould be achieved by th e use of another gear an d a clutch system. The design could also beimproved by increasing th e size of th e b uo y to generate a larger buoyancy force.

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The location used in the design is Cape Elizabeth which is 45 NM northwest ofAberdeenWashington. The design is location specific and depends on the height of the waves and theirfrequency. A change of location will change the hanging mass, buoy mass, pulley radius,velocity of the shaft, and length of corrugated tubing.

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Appendices:

25.022.52. 017 5

1- 15.0o

1.oQJ7.55.02.5

Buoy Forecast - Surf ForecastBuoy 46041 - Central Elizabeth

Hti9h C+ 14 axis) rPtriod Cstcs iigh4 axis)

Figure A. 1 Wave data to calculate wave displacement, velocity, and accelerationHanging Mass

No Slip and No Stretch Relationship

(eq. 1.1)(eq. 1.2)

(eq. 2.1)(eq. 2.2)(eq. 2.3)(eq. 2.4)(eq. 2.5)(eq. 2.6)(eq. 2.7)(eq. 2.8)

Primary Swell47.34N 124.75W Data Updated On: 03/11/2010 tO6zFAQs

Height Period Direction Buoy 46041

. 0

C)1)

0C.llj0

.. .0 r-.r r-. iCl Cl ClI I IN r.J NC) a lb

Tire (Day

l 0 Cl r. 10 a II) -. .0 10 Cl C) C)r. r. r-. ID 0) 10 r. .0 10 10 F. I) - Cl Cl Cl Cl Cl Cl Cl Cl Cl Cl Cl Cl Cl Cl ClI I I I I I I I I I I I I I IN N N N N J N N N N N N N N N-. C) 0 II) C) 0 LI) 1 C) a 11) 1 C) 0Cl 0 .4 Cl 0 0 .4 Cl 0 0 .4 Cl 0 0.4 Cl Cl Cl Cl C) C) C) I) + U) lboc month/Hour in G1T) and Direction (in

C. a -. a F. U) 0 U) .4 * .4 U) 0 II) Li) II) 10 10 .0 9 10 C-Cl Cl Cl Cl Cl Cl Cl Cl Cl Cl Cl Cl ClI I I I I I I I I I I IN N N N N N N N N N N N Nlb 4 C) 0 Lb . C) 0 Ii) .4 C) 0 lb Cl 0 0 Cl 0 Cl 0 0 .4LI) 11) 10 10 10 C. F. C. C. 0) 10 10

degrees) Copyright 2010 Stormsurf

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Shaft(eq.3.1)

A=O

F=O (eq.4.1)A + B = 0 (eq. 4.2)MA = 0 (eq. 5.1)(x +xB = 0B = 0 >> A = 0

F=0 (eq.6.1)Ax+Bx(mf+mp+ms)gTgTm=0 (eq.6.2)MA = (eq. 7.1)fmfrfmrPI-mSrSG +(Tm Tg)rp =\ 2 (eq. 7.2)

BuoyFb,X = 0 (eq. 8 .1)Fb,b (A + B) (mb + mG)g = 0 (eq. 8.2)MA=O (eq.9.1)x2(Fb,b mgg) (x +x(B + mpg) = 0 (eq. 9.2)

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A

%Bending Momenty=O;for x=O:.OO1:I;

y=y+l;if x(xl+x2) & x


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endif x>(xl+x2+x3)

BM(y, 1)=BM(z3, 1)+SF(y,1)*(xx1x2x3);end

end%Torquey=O;for x=O:.OO1:I;y=y+l;if x(xl+x2)

TO(y, 1)=O;end

end

%Geornetry Propertiesc=rs;A=pi*c2;Ix=(pi*c4)/4;Iz=Ix;ic=(pi*c14)/2;Q.A*4*c/(3*pi);

%Max shear andMaxPS=O;MaxSS=O;r=16;angle=360/r;y=O;for x=O:.OO1:I;y=y+;or s=1:1:r;t=(360/r)*s;xl(y,s)=c*cos(t);yl(y,s)=c*sin(t);NS(y,s)=BM(y,1)*yl(y,s)/Ix; SS(y,s)=(x1(y,s)*SF(y,1)*QJ(Iz*t))i((TO(y,1)...*c)/Jc);OC(y,s)=(NS(y,s)/2);SSm(y,s)=sqrt((SS(y,s)2)-i-(OC(y,s)2));

Principle Stress using Mohrs Circle

frDSllIii r

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.74

PSMAX(y,s)=OC(y,s)+SSm(y,s);if SSm(y,s)>MaxSS

MaxSS=SSm(y,s);sMaxSS=s;xMaxSS=x;

endif MaxPS

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