An Electric Auxiliary Engine for An Electric Auxiliary Engine for a Sailboat Using Renewable a Sailboat Using Renewable

EnergyEnergy

A Capstone ProjectA Capstone Project

Presented at thePresented at the

4th Annual Dayton Engineering Sciences 4th Annual Dayton Engineering Sciences SymposiumSymposium

Professor Russell K Marcks, P.E.Professor Russell K Marcks, P.E.

Impetus Behind This ProjectImpetus Behind This Project• Do we integrate enough electrical Do we integrate enough electrical

into our mechanical curriculum?into our mechanical curriculum?

ME ME MagazinMagazinee

Oct 2005Oct 2005

Impetus Behind This ProjectImpetus Behind This Project• Energy and Environmental Concerns While We Energy and Environmental Concerns While We

PlayPlay

Oil/Gas discharge of Oil/Gas discharge of two-stroke operating two-stroke operating at ¾ throttle for 15 at ¾ throttle for 15 minutes with no loadminutes with no load

Impetus Behind This ProjectImpetus Behind This Project• Apply familiar concepts to unfamiliar applicationsApply familiar concepts to unfamiliar applications

Impetus Behind ProjectImpetus Behind Project

• Promote Team Work and Promote Team Work and CommunicationCommunication– Hull and Prop (4 members)Hull and Prop (4 members)– General Mechanical (5 members)General Mechanical (5 members)– Charging and Electrical (7 members)Charging and Electrical (7 members)

• Team MeetingsTeam Meetings

• Project Review MeetingProject Review Meeting

• Project PresentationProject Presentation

• Convert original 15 hp gas Convert original 15 hp gas engine to a DC electrical motorengine to a DC electrical motor

• DC Motor must power craft from DC Motor must power craft from dock to hoisted sailsdock to hoisted sails

• Craft to move at a minimum Craft to move at a minimum speed of 3 knots for speed of 3 knots for approximately 30 minutesapproximately 30 minutes

• Alternative Energy based Alternative Energy based charging system to recharge charging system to recharge batteries while sailingbatteries while sailing

• Emergency backupEmergency backup

Design CriteriaDesign Criteria

Design CriteriaDesign Criteria• Use Wind Generators, Solar Use Wind Generators, Solar

Panels, Tow Generator or Panels, Tow Generator or freewheeling to generate freewheeling to generate power for the batterypower for the battery

• Electricity must support all Electricity must support all electrical systems required electrical systems required at night and during normal at night and during normal sailing operation (radio, sailing operation (radio, cabin lights, nav lights, etc)cabin lights, nav lights, etc)

• Equipment may be replaced Equipment may be replaced to optimize efficiencyto optimize efficiency

• 1978 sail boat optimized for 1978 sail boat optimized for today's productstoday's products

Determining Forces on HullDetermining Forces on Hull

• Drag on the hull (Drag on the hull (FFdd))– FFdd=.5*C=.5*Cff**ρ*S*Vρ*S*V22

• Force due to acceleration (Force due to acceleration (FFaa))– FFaa=m*a=m*a

– Decided on an acceleration of 0.1 ft / secDecided on an acceleration of 0.1 ft / sec22 (50 sec to reach max velocity)(50 sec to reach max velocity)

• Force due to waves in the water (Force due to waves in the water (FFww))– FFww=C=Cww**ρ*Sρ*S2/32/3*V*V2 2 where V is wave velocity where V is wave velocity

– Based on a moderate wave height (~4 to 8 ft)Based on a moderate wave height (~4 to 8 ft)

• ΣF=FΣF=Fdd+F+Faa+F+Fww

LossesLosses

• Propeller SlipPropeller Slip–Assumed 45% slip (typical for Assumed 45% slip (typical for Sailboat)Sailboat)

• Lower Unit Mechanical EfficiencyLower Unit Mechanical Efficiency–MeasuredMeasured

Efficiency of the PropEfficiency of the Prop•Efficiency is a function of the slip and the pitch ratio Efficiency is a function of the slip and the pitch ratio (diameter/pitch)(diameter/pitch)•Increases ΣFIncreases ΣF

LossesLosses

• Attached pulley & weight to propeller shaft (output)Attached pulley & weight to propeller shaft (output)• Attached torque wrench to motor shaft (input)Attached torque wrench to motor shaft (input)

– Multiple TrialsMultiple Trials– Increasing WeightIncreasing Weight– Plotted efficiency vs.Plotted efficiency vs.

Input TorqueInput Torque– Assumed 80% EfficiencyAssumed 80% Efficiency

OverallOverall

Propulsion Calculations and Motor Propulsion Calculations and Motor SelectionSelection• Developed SpreadsheetDeveloped Spreadsheet

For Propulsion CalculationsFor Propulsion Calculations

• Mars PMG 132Mars PMG 132– 24V to 72V24V to 72V– 110 Amp Continuous110 Amp Continuous– 200 Amp for 10 Min200 Amp for 10 Min

– Light (24.8 lbLight (24.8 lb))

85% efficiency at Running Speed of required 5.067 ft/s

5.303hp to produce a Running Speed of required 5.067 ft/s

Energy Consumed With Motor Efficiency

0

2

4

6

8

10

12

1 6 11 16 21 26 31 36 41 46 51 56

Time (s)

En

erg

y (k

J)

Energy Consumed WithMotor Efficiency

Peak Energy Consumed at 51s

Energy Consumed Per

Second Decreases at

52s. (5.067ft/s)

Energy ConsumptionEnergy Consumption

Controller ComponentsController Components•Controller - AXE 4834Controller - AXE 4834

–24 – 48V24 – 48V–Current Limit: 300ACurrent Limit: 300A–5 min rating: 200A5 min rating: 200A–1 hour rating: 135A1 hour rating: 135A–Voltage drop @100A: 0.30VVoltage drop @100A: 0.30V

•Throttle - Curtis type Throttle - Curtis type PotboxPotbox

–Inexpensive ($85)Inexpensive ($85)–User Interface to controllerUser Interface to controller–Controls current sent to Controls current sent to motormotor

•Pre-Charge ResistorPre-Charge Resistor•Contactor Contactor •FuseFuse•Ignition switchIgnition switch

Battery Life

0

20

40

60

80

100

30 34 38 42 46 50 54 58 62 66 70 74 78 82 86

Time (min)

Per

cen

t B

atte

ry

Rem

ain

ing

85% of Battery Life Will be Remaining after 30min Drive Time

Battery Life Will Be Depleted After 86min

Drive Time

Battery Life EstimateBattery Life Estimate

POWER GENERATION POWER GENERATION AND ELECTRICAL AND ELECTRICAL

SYSTEMSYSTEM

Distribution of PowerDistribution of Power

MOTOR HOUSE

WIND SOLAR

AC GENERATOR DOCKSIDECHARGER

BATTERIES

WATER

Battery Power - MotorBattery Power - MotorMotor Batteries: Motor Batteries:

(8x) Group 31, 140 amp hour(8x) Group 31, 140 amp hour12 volt, wet-cell, deep cycle marine battery12 volt, wet-cell, deep cycle marine battery13.00" L x 6.75" W x 9.50" H, 63.40 Lbs.13.00" L x 6.75" W x 9.50" H, 63.40 Lbs.

Motor will draw 110 amps at design speedMotor will draw 110 amps at design speed

System is a 48V 280Ah bank. Since marine batteries System is a 48V 280Ah bank. Since marine batteries should not be discharged below 50% charge, leaving 140Ah should not be discharged below 50% charge, leaving 140Ah to work with. Propulsion team estimates batteries 15% to work with. Propulsion team estimates batteries 15% discharged after powering the boat to a sailing position. discharged after powering the boat to a sailing position. This allows more power for returning and also providing less This allows more power for returning and also providing less dependency on recharging tools while sailing.dependency on recharging tools while sailing.

Wind and Tow Generators and Wind and Tow Generators and ControllersControllers• Wind GeneratorWind Generator

– Rutland 913Rutland 913– Had highest outputHad highest output– Quiet in operationQuiet in operation– Low wind start upLow wind start up– 24 VDC multi-bank 24 VDC multi-bank

controllercontroller

• Tow GeneratorTow Generator– Low start up speedLow start up speed

– High outputHigh output

– Fresh waterFresh water

– 24 VDC multi-bank 24 VDC multi-bank controllercontroller

Charging CircuitCharging Circuit

Electrical diagram for motorElectrical diagram for motor

House Amp DrawHouse Amp Draw

4.4 2 2.2Portable DVD player

0.2 2 0.1Compass

0.104 4 amps with 2 fixtures .026(5)

light, cabin courtesy lighting LED (5 fixtures)

.5 (15 min) 0.25 2Light, Foredeck lighting

0.125 0.5 .04-.25Light, Masthead (LED)

0.5 2 .04-.25light, stern (LED)

0.336 2 0.168Light, starboard (LED)

0.336 2 0.168Light, Port (LED)

0.8 8 0.1Light, anchor (LED)

.768 (10 min) 0.16 4.8Light, handheld spotlight

1.2 12 0.1Knotmeter

0.6 2 0.3Inverter (Cell Phone)

1.2 12 0.1GPS

1.2 12 0.1Depth Sounder

.625 (15 min) .25 2.5Bilge Blower

2 2 1AM/FM/CD Radio

18 12 

.5-1.5Amps depending

on trimAuto Pilot

Power ConsumedAmp-Hours/Day=

UsageHours/DayXAmpsAppliance (DC Power)

House Amp Draw

 37.71    Total Amps/Day 

Good for up to 20 hours use(90% standby)

0.33 8 0.04Handheld VHF radio (M72) charger

 1.25 0.25 5Radio, VHF, transmit

 3 2 1.5Radio, VHF, receive

If using Handheld VHF radio

        

 48.38    Total Amps/Day

 3.5 7 0.5Radio, VHF, standby

 1.25 (15 min)

0.25 5Radio, VHF, transmit

 10.5 7 1.5Radio, VHF, receive

 0.2 2 0.1Wind Speed Indicator

If using Built in

VHF radio

 

Power ConsumedAmp-Hrs/Dy=

UsageHours/DyXAmpsAppliance (DC Power) 

House Battery and Solar Panel House Battery and Solar Panel SelectionSelection

House Battery: House Battery: (1x) Group 27(1x) Group 27

12 volt, 110 amp hour12 volt, 110 amp hour

wet cell, deep cycle batterywet cell, deep cycle battery

12.00" L x 6.75" W x 9.88" H12.00" L x 6.75" W x 9.88" H

51.00 Lbs.51.00 Lbs.

Panels: Panels: Hatch and Radar-Arch Mounted Hatch and Radar-Arch Mounted

23.04 amp-hours generated 23.04 amp-hours generated based on 4.5 hrs sunlight/dybased on 4.5 hrs sunlight/dy

Radar Arch AnalysisRadar Arch Analysis

• 1-1/2” x .120” Wall Tubing1-1/2” x .120” Wall Tubing

• Stainless steelStainless steel

• ABYC (American Boating & ABYC (American Boating & Yachting Council) Yachting Council) standards require support standards require support for 200-lb load with no for 200-lb load with no more than 12” of more than 12” of deflectiondeflection

Resultant Displacement

Stress Distribution

General MechanicalGeneral Mechanical

Motor MountingMotor Mounting

Upper Intermediate HousingUpper Intermediate HousingInput Shaft

Seal has been removed

The upper intermediate housing adapts the original gasoline engine to the lower unit.

It is this plate that needs be redesigned to adapt the DC motor to the same housing

Lower Intermediate HousingLower Intermediate Housing

Water Pump

The lower intermediate housing remains.

Note the water pump needs to remain to support the input shaft. The impellor is removed.

Not the splined input which needs to be adapted to a keyed motor shaft.

Shift Rod and Water Shift Rod and Water PassagesPassages

Shift Rod

Water Passages

The lower intermediate housing with water pump removed.

Cooling water enters around shift rod. Must block off water from DC motor while maintaining shifting capability.

Intermediate Housing Intermediate Housing AdapterAdapter

Bottom of Motor Spacer

Locating Rings

Adapter Plate

Motor SpacerMotor Spacer

Top View of Motor Spacer Locating

Rings

Crankshaft ModificationCrankshaft Modification

Cut HereAnd here

Crankshaft ModificationCrankshaft Modification

Secured by set screws

Connecting Sleeve is

fabricated

Crankshaft is turned down and keyway cut

into shaft

Housing adapter Bolts to existing lower intermediate housing

Motor spacer will allow mounting of different motors if desired

Gas Engine OperationGas Engine Operation

Water Enters

Travels Across Bearing Housing

Travels up through lower unit housing

Fills Intermediate Housing

Pumped throughout the engine for cooling

Modification of HousingModification of Housing

Block off water intake port

Drill Hole to allow oil to

enter and fill cavity

Modification of HousingModification of Housing

Block off water passage

Drill Hole to allow water to escape cavity

Student Writing Assignment Student Writing Assignment Installation / User ManualInstallation / User Manual

Student Writing Assignment Student Writing Assignment Installation / User ManualInstallation / User Manual

Student Writing Assignment Student Writing Assignment Installation / User ManualInstallation / User Manual