36
1

PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

  • Upload
    others

  • View
    0

  • Download
    0

Embed Size (px)

Citation preview

Page 1: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

1

Page 2: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

2

July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here is the final report on the design of the hybrid boat PHISH as part of our Marine Field Project. We’ve enjoyed our work on this project, and would be happy to answer any questions. Sincerely, Team PHISH

Page 3: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

3

PHISH Perfected High-speed

Internal-combustion Solar Hybrid

Department of Ocean Engineering Florida Institute of Technology

Melbourne, Florida

Adam Lucey Mark Stroik Zak Chester Enrique Acuna

July 27, 2005

Page 4: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

4

Table of Contents 1.0 Cover Page 1.1 Letter of Transmittal 1.2 Title Page 1.3 The Executive Summary 2.1 Introduction 2.1.1 Problem statement and constraints 2.1.2 Objectives 2.1.3 Background and Importance 2.1.4 Scope of the Report 2.1.5 Sources of Information 2.2 Methods 2.2.1 Chain and Sprocket Design 2.2.2 Maintenance 2.2.3 The Clutch 2.2.4 Propeller Angle and Strut Assembly

2.2.5 Engine and Strut Mounts 2.2.6 Machining 2.2.7 Solar Panel Assembly 2.2.8 Rudder

2.3 Results 2.4 Discussion 2.4.1 Objectives accomplished

2.4.2 Differential 2.4.3 Alternatives and Unique Design Aspects 2.4.4 Design Uncertainties 2.5 Conclusions 2.6 Recommendations 3.0 References 4.0 Appendixes 4.1 Budget Analysis 4.2 Curves of Form 4.3 Section Area Curves 4.4 Cross Curves of Stability 4.5 Hydrostatic Properties 4.6 Pro Surf and GHS drawings

4.7 Hull specifications

Page 5: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

5

1.4 Executive Summary

Team PHISH, an acronym for Perfected High-speed Internal-combustion Solar Hybrid, was created to determine if a hybrid propulsion system was feasible in the marine industry. The proposed task was to create a boat that has multiple power sources. PHISH utilizes a combination of electric-solar and gasoline engines. This combination was chosen due its simplicity, following a similar trend in the automotive industry. Several other hybrid systems are also available such as hydrogen-electric propulsion. The completed project was successful and the objectives were achieved. The boat reached a top speed of 5 knots. All systems worked properly; however, the top sprocket was misaligned and caused the chain to vibrate off at high speed. Future recommendations and changes should include the trial of a serpentine belt system and tensioner which should eliminate the vibration. Further testing should be done determine if it is feasible to draw a current from the electric motor to charge the battery instead of the solar panel since when the gas motor is engaged the electric motor is still spinning. It may be possible to use the electric motor as a generator as well.

Page 6: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

6

2.1 Introduction

2.1.1 Problem Statement and Constraints As an engineering team, we needed to design, test, and build a hybrid propulsion system to be utilized in the marine industry. The hybrid must include two distinct power sources, aimed at lowering operating costs, and decreasing emissions using renewable energy. The system needs to be economically feasible, and easily fitted to a test hull. 2.1.2 Objectives The goal of this project is to blend automotive hybrid technology, solar energy and the marine industry. The “hybrid boat” borrows the parallel hybrid system used in automobiles and incorporates it into a small test hull. The second objective is to create a feasible and reliable hybrid system for marine implications. Not to phase out gasoline and diesel engines entirely, but to blend them with modern hybrid and electric technology. The blend of power sources will reduce the operating costs and emitted pollutants. On a larger scale the hybrid propulsion system can be integrated into the commercial and private sector by modifying existing propulsion systems. 2.1.3 Background and Importance Marine shipping and transportation is a major industry, profiting in billions each year. However, operating costs, which are due largely in part to fuel expenses, offset the profits. Large vessels, usually equipped with diesel engines, are most efficient at certain speeds. When the vessel is not traveling at this speed it is inefficient and thus more costly. This problem does not only affect large tankers and cargo ships. The ever-rising price of gas is also having an impact on the private market, such as pleasure boats. Even with the recent advances in four-stroke engine technology, and more efficient internal combustion engines, the average household cannot afford to own a boat.

Page 7: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

7

In the past decade there has also been growing concern about emissions and pollution caused by internal combustion engines. This can been seen in the auto industry. There are currently several hybrid cars on the Market with more planned for future release. These hybrids rely on either a gasoline engine or generator and an electric motor. Currently there are two main types of hybrids used: Parallel and series. In a parallel hybrid the gasoline engine and the electric motor are independent. The electric motor utilizes battery cells and is charged during engine break periods or via an alternator. The motors are coupled to a transmission or differential and can power the vehicle separately. In a series hybrid, the gasoline engine never directly powers the wheels. Instead, the engine is used to power a generator, which is used to charge the batteries for the electric motor or directly power the electric motor. In a hybrid the role of pushing the car is divided between two motors. The gasoline engine can be made smaller, coupled to the electric motor it can perform the same task as a single larger engine. A smaller engine is more efficient; therefore, reducing the price of fuel and emissions. The hybrid system becomes more capable with the use of the electric motor since it requires only electric power and is efficient at all speeds. PHISH will also utilize solar energy to charge to battery need for the electric motor when not in use. Using the solar panel means the electric system is completely renewable and has zero emissions. 2.1.4 Scope of the Report Included in the report is a comprehensive procedure, accounting all major steps and design concepts. It also includes all diagrams and drawings accompanying the design. The results of project PHISH as well as a discussion and conclusions section are located in the appropriate sections. Finally, the future recommendations for the project are included and additional materials are located in the appendixes.

Page 8: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

8

2.2 Methods 2.2.1 Chain and Sprocket Design A chain and sprocket design was devised to reduce rotations on the drive shaft. Through this design concept, we developed a chain and sprocket design that operated the gas motor and electric motor independently, driving one propeller shaft. The chain and sprocket is a type of gear assembly since there is a reduction in rotations between two drive shafts using teeth. There are ten teeth on the sprocket of the gas motor while there are thirty teeth on the sprocket of the electric motor and propeller shaft. The gear ratio is 3:1, reducing the speed of the gas motor from 3300 rotations per minute to 1100 rotations per minute. This new design was economical and practical without precision alignment of expensive gears and bearings. Chain and sprockets also prevent slippage between the gears. Therefore, axles connected by sprockets are always synchronized exactly with one another. This design is devised so the gas and electric motor is mounted vertically from one another using a 2x6 wooden mount, while the propeller runs parallel with the drive shafts. The propeller shaft is sheltered to the hull with a strut/bearing assembly mounted inside of the boat.

Figure: Chain and sprocket design drawing

Page 9: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

9

Figure: Chain and sprocket image

2.2.2 Maintenance The chain and sprocket assembly will withstand a lot of abuse, but is far from invincible. A chain that breaks or jumps off of the sprockets can easily snag on the countershaft sprocket, and lock up the drive shaft (propeller) ultimately causing severe damage to the hull, stuffing box, and propeller shaft. This can happen from vibration, or in extreme cases, the chain skipping on the sprocket when the drive train components have had enough. Prototypes and full scale boats with this assembly should maintain proper maintenance as time comes to replace any one of the drive train components—chain, countershaft sprockets or rear drive sprocket. This can be done with an Alan key and any tool used to remove the chain’s master link. There are a few different methods for determining whether a chain needs to be replaced. Start by wrapping the chain around the electric motor sprocket. Hold the two ends of the chain with one hand and apply pressure away from the sprocket. With your free hand, pull the chain on the other side of the sprocket in the opposite direction. A chain that stays tight and does not lift too far off of the sprocket’s teeth is still in good shape. However, a chain that lifts far enough that you can see the top of the teeth on the sprocket is worn too much and must be replaced. It is also a good idea at this time to check for damaged rollers and loose pins and links. If the sprocket is wearing to the point that you can visibly see the wear, it is time to replace it. Because of the torque, sprockets tend to wear in the direction opposite of rotation. Chain lubrication should also be applied to the assembly regularly.

Page 10: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

10

2.2.3 The Clutch The drive shaft on the gas motor spins at 900 rotations per minute when the motor at idle. A clutch is used to eliminate the propeller shaft from spinning with the gas motor at idle, allowing the gas motor shaft to spin freely at low rpm’s. The throttle becomes the single control for engaging or disengaging the power, as well as controlling the operating speed. Speed up the engine and engage the drive train - slow down the engine and it disengages. This automatic clutch is preset to engage at approximately 2,200 rpm. With the gear reduction, the propeller engages at 734 rotations per minute. This engagement speed level protects the operator, as well as the power transmission system during engine cranking, starting and idling. This clutch also provides smooth engagement, which protects the engine and drive train against shock and high initial starting stresses. In the event of an overload, the engine will be lugged down to a slower speed, which will automatically disengage the clutch. Once the overload condition has been eliminated, the clutch will reengage and operate normally.

Figure: Max-Torque Clutch supplied by Grainger

2.2.4 Propeller Angle and Strut Assembly The angle of the shaft is as close to parallel to the waterline as the shape of the hull allows. This is done for several reasons. First, the gas motor lubricates itself best when it is installed as nearly horizontal as possible. Second, a shaft emerging from the hull at a steep angle presents more frontal area and more drag than one which parallels the flow of water. Third, for most efficient propulsion under power, the angle of thrust of the propeller should be in the direction you want the boat to travel. For our design, a propeller shaft angle of thirteen degrees was used to maximize our propeller

Page 11: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

11

efficiency with a 3 inch clearance between the propeller and the hull. This large clearance allows for additional security so the propeller will not damage the hull under certain situations such as running aground. Once an angle was calculated, we used a strut assembly of three bearings and a steel mount inside of the boat. Although the strut of a high speed small craft is usually a metal strut, positioned in front of the prop, which located outside of a boat, a strut on the inside of our boat is better in design because more stress and weight of the propeller shaft is applied closer to the drive sprocket in the interior of the boat. The strut assembly was designed from a series of three bearings and two shaft collars that clamped the bearings into place. Bearings reduce friction by providing smooth metal balls or rollers, and a smooth inner and outer metal surface for the balls to roll against. These balls or rollers are responsible for holding the load, allowing the propeller shaft to spin smoothly. The main center bearing used is a radial bearing that is attached to a steel mount that is ultimately attached to a wooden mount fiber glassed to the hull. The other two bearings, outside of the radial bearing, are thrust bearings. These bearings prevent the vertical thrust on the propeller shaft.

Figure: Thrust Bearing

Figure: Radial Bearing with Steel Mount

Page 12: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

12

Figure: Strut Assembly; CAD Drawing from outside to center: two shaft

collars, two thrust bearings, and a center radial bearing.

Figure: Strut Assembly; Image

With 1100 rotations per minute, minor concerns include bent or broken shafts, drive system vibration damaging engine mounts and the boat hull itself, and bearing failure caused by increased stress on the rear output shaft bearings and sprocket. These are but a few of the damages that can be caused by basic engine/shaft misalignment and system vibration. 2.2.5 Engine and Strut Mounts The engine and strut mounts were all formed out of 1/2” plywood, which were secured to the hull. Each mount needed to have a specific angle, calculated using geometry, as to get the proper angle of the propeller shaft. Once all mounts were secured they were glassed in and mounted permanently. 2.2.6 Machining Bearings, shafts, sprockets, and the chain were supplied by McMaster-CARR. The electric motor shaft, gas motor shaft, and drive shaft are ¾” and keyed to fit all three keyed sprockets with bore holes matching shaft diameter. The propeller shaft is stainless steel and non-keyed. Shaft collars were clamped with roll pins through the shaft collar and shaft. All machining was done at the Florida Tech Machine Shop.

Page 13: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

13

2.2.7 Solar Panel Assembly The Kyocera solar panel was supplied by the school. Using a multimeter, the panel was tested and output 18.50 volts at 8 amps in direct sunlight. The solar panel was mounted in a sealed box constructed of .280” clear acrylic. The whole enclosure was then mounted directly of the seat. This location was chosen due to the limited space within the hull. It also allowed all of the controls to be built off of the mounts, which tied all structural components together. In order to prevent the flow of current in the wrong direction a 6 amp diode was placed inline of the power wire. From here the solar panel can be wired directly to the battery. This allows the solar panel to continually charge the battery. 2.2.8 Rudder The rudder consists of a Styrofoam core with laid fiberglass. A half inch steel shaft will be drilled down the center axis of rotation. Rudder area was calculated using J.B. Haddler’s equation:

Ap = 0.0016 Lp^2 = 12.96 inches Where Lp is the projected chine. Styrofoam was taken from an old surfboard, and formed by hand using the above calculation

2.3 Results The final testing was successful. All components of the hybrid systems worked as they were supposed to. The boat achieved approximated five knots on one quarter throttle. This was due to misalignment of the sprocket on the electric motor. Since this top sprocket was slightly out of alignment and would not stay properly secured to the shaft it would vibrate off the clutch as engine reached higher RPMS. The Solar panel worked properly as well, however is did not supply enough energy to run the trolling motor directly off of the solar panel.

Page 14: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

14

2.3.1 Static Stability Tests The static stability of a ship refers to its ability to resist a heeling moment while at rest. Stability is achieved through a balance of upward buoyant forces and downward gravitational forces as they act around the centers of gravity and buoyancy. To determine the locations where the resulting moments are introduced, the following tests were conducted. The tests were conducted under the supervision and guidance of Mark Cencer. The following section has been derived from a report, submitted by Mark to DMES, which was intended for use by following MFP projects. 2.3.1.1 Determining Vessel Displacement Purpose: To determine the displacement of the vessel in order to find the magnitude of the vertical forces on the vessel. Background: According to Archimedes Principle, the weight of an object immersed or partially immersed is equal to the weight of the fluid displaced. Therefore, the displacement of the hull may be determined by weighing the hull on land. Procedure: The hull was weighed using a simple bathroom scale. A second displacement was obtained after the removal of the deck. The final displacement was obtained by adding the outfitted hull to the individual weights of the driver, engine, battery and solar panel. Results: Initial Displacement: 72 lbs Empty Displacement: 34 lbs Final Displacement: 268 lbs Also See Appendix… Discussion:

Page 15: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

15

Due to Archimedes Principle, stating the equality of gravitational and buoyancy forces, no further tests are needed in the determination of displacement values. The goal weight for PHISH was approximately 250 lbs. The final displacement is within an expectable range of this value, since the builders had no methods of determining exactly how much weight would be added in the process of hull modifications. 2.3.1.2 Determining Center of Gravity As in the location of any point the determination of the center of gravity of the vessel requires finding the values of three coordinates. In this case these coordinates are measured with respect to a single point at the stern of the ship, along the baseline, and the centerline. Therefore in order to determine the center of gravity of the ship three coordinates need to all be measured with respect to this point. These three coordinates are the transverse center of gravity, longitudinal center of gravity, and the vertical center of gravity. These points can be found with a series of simple experiments. First, the balance experiment can be used to determine the longitudinal center of gravity. Second, the inclining experiment can be performed to find the vertical center of gravity. Because of symmetry the transverse center of gravity can be assumed to be along the center line of the vessel so no experiment is necessary to determine it. 2.3.1.3 Balance Experiment: Longitudinal Center of Gravity Purpose: To determine the center of gravity of the hull to predict any significant trim. Theory/Procedure: Place the vessel across a wedge to act as a pivoting point at a set distance from the stern. Lift the bow of the vessel with a fish scale until the vessel is level. The distance from the pivot point to the LCG can then be found with a simple moment balance: Fa = Wx Then the position of the LCG with respect to the after perpendicular

Page 16: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

16

is equal to the distance from the after perpendicular to the pivot point plus the distance from the pivot point to the LCG. Results: Due to the fragile condition of the hull at the time of testing this test was not performed, so as to avoid compromising the structural integrity of the hull. 2.3.1.4 Inclining Experiment: Vertical Center of Gravity Purpose: To determine the vertical center of gravity of the hull in order to predict the vessels static stability. Background: The vertical center of gravity (KG) is the distance from the baseline or keel to the center of gravity. It is determined with another simple experiment: the inclining experiment. In this experiment the distance from the keel to the center of gravity, KG, is found from the difference from the keel to the metacenter, KM, and the distance from the center of gravity to the metacenter, GM. Theory/Procedure: To perform this experiment a mast needs to be mounted along the transverse centerline of the vessel. Then a weight is suspended on a string from the top of the mast. Weights are placed on the deck at different distances from the centerline and the vessel heels. The length of the string, distance from the weight to the vessels transverse centerline, and the distance the weight on the string moves away from the mast are all measured in order to determine the heel angle. Then the distance from the center of gravity to the metacenter can be determined: GM = wt/Ç tan å a listing of hydrostatic curves for each hull spacing, the distance from the baseline to the metacenter (KMT) can be determined, then: KG = KMT - GM This is fairly accurate except that the location of the center of gravity is altered by the position of the weights added. A correction factor must be introduced to offset the effect of the location of the

Page 17: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

17

weights used for the experiment. This correction factor is given by: KG = KG1Ç1 - Ìwkg / Ç where KG is the corrected position of the center of gravity, KG1 is the experimental position of the center of gravity, Ç1 is the experimental displacement including the weights added, w is the weight added, kg is the vertical position of the weight added, and Ç is the actual displacement. The experiment is run by placing several weights on the deck of the ship then sliding each one to one edge of the deck or the other and noting the heeling angle each time. Then GM can be found from a plot of the inclining moment (wt) vs the tangent of the heeling angle (tanå). GM = slope / Ç Results: Inclining Experiment Determine vertical center of gravity

L (in) 40

t (in) 15.5

? (lbs) 110

Deck 16.5in

KMT (in) 19.6

w (lb) a(in) w*t (lb-in) Tan F

3 1.5 46.5 0.0375

6 3.5 93 0.0875

9 6 139.5 0.15

12 8.25 186 0.20625

15 12 232.5 0.3

18xxxx xxxx xxxx

Slope 986.39 GM1 (in) 8.9671818 KG1 (in) 10.632818 GM (in) 13.184219 KG (in) 6.4157813 Discussion: The experiment is supposed to be run with all of the weights placed on the deck to begin with. Then the weights are slid into different positions on the deck causing the ship to heel. This way the displacement stays constant throughout the experiment and the weights used can be adjusted for with a simple correction equation. If this is done all of the inclining moments can be plotted against

Page 18: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

18

the tangent of the heeling angle.Then the slope of the plot divided by the displacement would give a single GM value that could be subtracted from a single KMT value found for at one displacement from the hydrostatic curves. Then a simple correction factor could be used to adjust for the weights added to the boat for the experiment. The procedure is fairly simple. But, instead of performing the experiment this way the weights were added to the deck in 2.5 lb increments and the heeling angle was measured. This will ultimately yield the same results, but the data analysis is more complicated because the displacement of the vessel changes at each different heel angle. To make up for this a different GM and a different KMT must be found for each weight addition. This is done with a fairly similar procedure. First, the inclining moment is still plotted against the tangent of the heeling angle. The GM is still equal to the slope of this line divided by the vessels displacement. But now this must be done for each displacement. Then, instead of using a single KMT value for a single displacement, the KMT values for each displacement must be found. Then these can be subtracted to find KG. Another problem with the method used, however, comes in the correction factor. Because the weights were stacked up the center of gravity of the weights gets higher with each weight. This would cause another error in the position of the vertical center of gravity. Also, the amount of weight being corrected for changes in each trial so this must be taken into account in the correction factor. Therefore, in order to correct this data a different correction factor must be used for each weight addition and heel angle and it must take into effect the amount of weight added and the vertical center of gravity of the weights added. Also, this must be done for each hull spacing as the values of KMT are dependent on the hull spacing. 2.1.3.5 Roll Frequency Test Purpose: To measure the average roll frequency of the vessel in order to predict how the vessel will roll as the hull spacing is changed. Background:

Page 19: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

19

Dynamic Stability it the ability of a vessel right itself while moving. The simplest example of this involves a stationary vessel rolling in waves. Roll frequency is dependent on both the ship's beam and the distance from the center of gravity to the metacenter: T = k B / ‰GM where k is a constant rolling coefficient, B is the ship's beam, and GM is the metacetric height. Then if the beam and metacentric height of a vessel are known and the roll frequency is measured the roll coefficient, k, can be determined. Then a relationship can be found to predict the roll frequency as the vessels beam and metacentric height, or hull spacing, change. Procedure: To perform this experiment one side of the vessel is heeled and then released. When the vessel is released it will roll back and forth. The time required for a known number of rolls can be measured. Then the average time per roll can be determined. This is the roll frequency, T. This can be done at each hull spacing with a known beam and metacentric height and a constant value of the coefficient k can be determined. Results: Roll Frequency ? (lb) 64 GM (in) 13.18 Beam: 27in Time (s) Cycles Avg (s)

7.36 6 1.226667 7.72 6 1.286667 7.21 6 1.201667

7.2 6 1.2 7.66 6 1.276667 7.43 6 1.238333

1.238333 k 38.68737 Discussion: The experiment yielded very consistent results. Two obvious factors stand out as possibilities for errors. The first is the human error in the start and stop of the

Page 20: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

20

timing device. Second is the possibility of wave action due to deflection from the boundaries of the testing site affecting the roll. These errors could be eliminated through the use of a more sophisticated experiment.

2.4 Discussion

2.4.1 Objectives Accomplished Returning to our objectives, our engineering team accomplished its goals. We designed and constructed a working hybrid propulsion system. This technology is potentially feasible in other areas of the marine industry. Perhaps using something other than a solar panel to charge to batteries, since the panel is relatively large when compared to size of the hull. 2.4.2 Differential The initial design was a differential including two input shafts and one output shaft. Simple spur and bevel gears were designed throughout the differential to decrease the speed of rotation, reverse the direction of rotation, and move rotational motion to a different axis. Together, these gears and shafts combined a 3hp gasoline engine and an electric trolling motor to power a single propeller shaft independently or in tandem. In tandem the power of the propeller shaft will be the summed power of both engines, minus power lost throughout the drive train.

Figure: Initial differential drawing

This design was not used due to a material constraint as spur and bevel gears exceeded our budget. There was also a time constraint because the precision in alignment between gears was crucial with little time in machining to create a

Page 21: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

21

perfect alignment. This was a major setback in our project. Our dilemma was that the gas motor spins at 3300 rotations per minute. Through cavitation equations, we estimated that the propeller will become useless at speeds exceeding 1000 rotations per minute. This problem could be corrected from a gear ratio reduction but our differential design could no longer be used. 2.4.3 Alternatives and Unique Design Aspects The sprockets and clutch assembly, discussed earlier, was driven with a chain, however we also considered using a belt drive system. Upon initial inspection it was thought that a v-belt system would allow too much slippage. There are several unique and unusual aspects of the PHISH design. Traditionally the strut for most inboard motor boats is located on the exterior of the hull; however, due to size constraints PHISH’s strut is located on the inside of the hull. The most unique feature is that two independent power sources can turn the same propeller, eliminating the need for two shafts. This setup allows us to utilize the advantages of each power source. The gas motor is primarily for speed and transit, while the electric motor is used for cruising at lower speeds and maneuverability in ports or dock. 2.4.4 Design Uncertainties One major concern was that the strut assembly and stuffing box would not be able to handle the RPMS of the gasoline engine. There was no way of testing this other than running the engine at full throttle. Fortunately, this was not the case. All parts of the strut assembly, thru-hulls, and stuffing box worked properly and held the shaft in place.

2.5 Conclusions

As stated earlier all systems worked as they were designed to. The issue with the electric motor’s sprocket will be corrected. This hybrid propulsion system with some further testing could be imported into larger boats. The advancements in

Page 22: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

22

hybrid technology, more specifically the marine industry will allow the operation of all boats and ships to operate at a lower cost. A lower operating cost of shipping could translate into lower priced goods for the public. Another benefit of developing the hybrid propulsion system found in PHISH is to aid in limiting the pollutants and emissions. Since you only need the gasoline engine to gain speed, on all other tasks you can use the electric-solar motor which has zero emissions. The design and construction of PHISH has proved that a hybrid powered boat is possible. As a prototype PHISH demands more testing to perfect the system and make it more reliable, and more compact.

2.6 Recommendations

To correct the issue of the electric sprocket a belt drive system should be tested. A serpentine belt drive may work well and eliminate the issue of slipping and vibrating. A belt tensioner should also be added which will make it easier to adjust the belt, rather than moving the whole motor to the left or right to adjust the tension of the chain. Another aspect that should be pursued is converting the electric motor into a generator rather than using solar energy. The electric motor is spinning constantly. Theoretically it is possible to pull a current off of the motor to charge the battery when it is not in use. This would allow the electric motor to act as both propulsion and generator. A follow-up on the differential is also necessary. Although it was not included on PHISH it is a unique design. With a proper budget and time the differential can be built. The differential can be used to attach any two power sources and have the ability to use their combined thrusts or individual efforts to spin the propeller shaft at any angle.

Page 23: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

23

3.0 References

http://www.mcmaster.com/ http://www.howstuffworks.com

http://www.rcboatmodeler.com/RB/reviews/super_spt45.asp http://www.grainger.com

http://marinesurvey.com/yacht/alignment.htm The Florida Tech Machine Shop

Page 24: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

24

4.0 Appendixes

4.1 Budget analysis

Item Cost Number Total Cost Bought By

Engine $220.99 3.5 HP Engine $220.99 1 $220.99 P/O Electric Engine $0.00 1 $0.00

Engine Rebuild $0.00 $94.65 Old engine $25.00 1 $25.00 AL Carborator $40.00 1 $40.00 AL Part $5.39 1 $5.39 AL gasket $3.49 1 $3.49 AL filter $4.69 1 $4.69 AL muffler $2.59 1 $2.59 AL spark plug $0.99 1 $0.99 AL nipple $3.99 1 $3.99 AL fuel fitting $2.15 1 $2.15 AL shaft and lever $5.33 1 $5.33 AL springs $1.03 1 $1.03 AL

Fittings $453.77 #40 Chain $18.12 1 $18.12 ZC Sprocket $29.40 2 $58.80 ZC 1/4" * 24" steel shaft $10.96 1 $10.96 ZC 5/8" * 6" steel shaft $11.74 1 $11.74 ZC 3/4" * 18" hardened steel shaft $38.94 1 $38.94 ZC 3/4" * 24" keyed steel shaft $31.41 1 $31.41 ZC Bearing Mount $31.11 1 $31.11 ZC Clutch $15.63 2 $31.26 ZC 3/4" collar $4.43 2 $8.86 ZC 1/4" collar $3.65 2 $7.30 ZC Thrust Bearing $3.64 3 $10.92 ZC 1" * 6" pvc $1.29 1 $1.29 ZC Hose $1.00 1 $1.00 AL

Hardware $102.63 Screws $3.28 1 $3.28 EA pullies $1.88 8 $15.04 EA springs $3.97 2 $7.94 EA Bolts $0.09 6 $0.54 ZC nuts $0.09 6 $0.54 ZC supplies $36.17 1 $36.17 ZC fasteners $3.49 1 $3.49 ZC Shelf Bracket $1.98 1 $1.98 ZC Hardware $0.45 1 $0.45 MS 3/8" lockwasher $2.75 1 $2.75 MS

Page 25: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

25

3/8" carraige $1.68 4 $6.72 MS 3/8" washer $0.09 12 $1.08 MS 3/8" nut $0.08 12 $0.96 MS Hardware $8.49 1 $8.49 MS nuts and bolts $0.40 1 $0.40 AL fasteners $0.27 4 $1.08 AL fasteners $0.33 4 $1.32 AL fasteners $0.10 8 $0.80 AL screw $0.52 1 $0.52 AL washer $1.03 2 $2.06 AL fasteners $0.20 2 $0.40 AL fasteners $0.17 3 $0.51 AL fasteners $0.02 3 $0.06 AL fasteners $0.25 3 $0.75 AL fasteners $0.20 3 $0.60 AL stainless hardware $2.35 2 $4.70 AL

Misc. $264.34 Blue Paint $19.96 1 $19.96 EA WhitePaint $6.59 1 $6.59 EA Primer $14.95 1 $14.95 EA supplies $6.36 1 $6.36 EA 333 solvent $10.59 1 $10.59 EA 2*4 $2.83 4 $11.32 EA 2*2 $2.19 2 $4.38 EA supplies $0.51 2 $1.02 EA 24 * 28 plexi $20.99 3 $62.97 EA supplies $2.67 1 $2.67 EA supplies $2.96 1 $2.96 EA Bottom Paint $30.36 1 $30.36 EA Spreaders $3.49 1 $3.49 ZC Spray Paint $6.97 1 $6.97 ZC Syringe $2.99 1 $2.99 ZC Stickers $14.99 1 $14.99 ZC Black Spray $3.29 $0.00 ZC Supplies $22.89 1 $22.89 ZC Supplies $10.49 1 $10.49 MS Starboard $5.00 1 $5.00 AL toggle switch $1.56 1 $1.56 AL electrical $0.15 3 $0.45 AL Supplies $0.28 1 $0.28 AL Red LED $1.99 1 $1.99 AL box $2.69 1 $2.69 AL electrical tape $0.60 1 $0.60 AL electrical $2.49 1 $2.49 AL Supplies $4.88 1 $4.88 MS Supplies $8.45 1 $8.45 MS

Page 26: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

26

Battery $0.00 1 $0.00 EA Solar Panel $0.00 1 $0.00 P/O Hull $0.00 1 $0.00 P/O

Abrasives $24.21 60 disc $7.99 1 $7.99 ZC Assort. Hand $2.49 2 $4.98 ZC 36 disc $4.49 1 $4.49 MS 36 disc $1.38 2 $2.76 MS 60 disc $3.99 1 $3.99 MS 100 disc $3.99 1 $3.99 MS 150 disc $3.99 1 $3.99 MS 220 disc $3.99 1 $3.99 MS

Fiberglassing $65.33 410 filler $7.09 1 $7.09 ZC 404 filler $6.49 1 $6.49 ZC 404 filler $6.49 1 $6.49 MS Acetone $5.69 1 $5.99 ZC Acetone $5.99 1 $5.69 EA Acetone $5.69 1 $5.69 MS brush $0.28 3 $0.84 AL resin $11.31 1 $11.31 AL cloth $1.25 3 $3.75 AL 404 filler $11.99 1 $11.99 MS

Tools $122.28 1/4 hole saw $4.49 1 $4.49 ZC Drill Bit set $12.99 1 $12.99 ZC Utility Knife $4.97 1 $4.97 MS Screwdriver Set $3.47 1 $3.47 MS Planer $7.46 1 $7.46 MS pad kit $9.58 1 $9.58 MS weld wire flux core $19.99 1 $19.99 AL Sander $49.88 1 $49.88 MS Hachsaw $7.46 1 $7.46 EA Saw Blade $1.99 1 $1.99 EA

Total: $1,348.20

Page 27: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

27

4.2 HydroStatics

HydroStatics

Displacement 34lbs Bare Hull

Draft 3.42in

LCB 50in from aft

VCB 1.71in from keel

Immersion 28lb/in

WPA 5.922ft^2

LCF 50in from aft

M/trim 11.88lb/in

KML 2.67ft

KMT 32in

Page 28: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

28

Page 29: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

29

Page 30: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

30

Page 31: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

31

Page 32: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

32

Page 33: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

33

Page 34: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

34

xa

Page 35: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

35

Page 36: PHISH Final Report - CASmy.fit.edu/~swood/PHISH.pdf · 2006-01-19 · 2 July 26, 2005 Ocean Engineering Department Florida Institute of Technology Melbourne, FL 32901 Dear DMES Here

36