06411 Mini Nucleating Bubble Engine

Steven NathensonSteven NathensonJoseph PawelskiJoseph PawelskiJoaquin PelaezJoaquin Pelaez

Andrew PionessaAndrew PionessaBrian ThomsonBrian Thomson

Project OverviewProject DescriptionProject Description

– Creation of a mini device (mm scale) that harnesses the Creation of a mini device (mm scale) that harnesses the energy from periodic vapor bubble formation (nucleation) in energy from periodic vapor bubble formation (nucleation) in a fluid resulting from heatinga fluid resulting from heating

– Current research MEMS devices use a micro scale (Current research MEMS devices use a micro scale (m) m) piezoelectric membrane to convert mechanical oscillations piezoelectric membrane to convert mechanical oscillations from bubble nucleation directly to electrical current.from bubble nucleation directly to electrical current.

– Project focuses on the development of a slightly larger (mini) Project focuses on the development of a slightly larger (mini) scale engine permitting greater experimental analysis scale engine permitting greater experimental analysis capability in addition to implementation in applications capability in addition to implementation in applications requiring mechanical energy.requiring mechanical energy.

– Periodic bubble nucleation is produced by a mini heater Periodic bubble nucleation is produced by a mini heater powered by a modulated power supply.powered by a modulated power supply.

Needs Assessment• Design ObjectivesDesign Objectives

– Size limitations – 1 ftSize limitations – 1 ft33 – Cost Cost – mm scalemm scale– Regulate the heater via a control systemRegulate the heater via a control system– Battery or power supply operatedBattery or power supply operated

• Standard sized batteryStandard sized battery• Voltage and amperage based upon the power Voltage and amperage based upon the power

requirements of heaterrequirements of heater– What type of fluid allows for the best bubble growth?What type of fluid allows for the best bubble growth?– Create a light weight systemCreate a light weight system– Successfully test deviceSuccessfully test device– Benchmark efficiency of engineBenchmark efficiency of engine– Bubble visualization with high speed cameraBubble visualization with high speed camera

• Develop Theoretical ModelDevelop Theoretical Model– System modelsSystem models

Technical Requirements• Performance RequirementsPerformance Requirements

– Mechanical oscillation greater than 5-10 HzMechanical oscillation greater than 5-10 Hz– Run time of 20 seconds or moreRun time of 20 seconds or more

• Functional RequirementsFunctional Requirements– Bulk fluid temperatureBulk fluid temperature

– Bubble growth surfaceBubble growth surface

• Yield the appropriate amount of bubbles from the heating Yield the appropriate amount of bubbles from the heating surfacesurface

– Minimize friction toMinimize friction to • Increase efficiencyIncrease efficiency

• Accurate bubble modelAccurate bubble model

Risk AssessmentMajor Project RisksMajor Project Risks

– Engine parts could be too unique and smallEngine parts could be too unique and small• May result in going over budgetMay result in going over budget• May result in lack of timeMay result in lack of time

– The engine design may be to similar to The engine design may be to similar to current MEMS devices if a piston or piston current MEMS devices if a piston or piston like design is not utilizedlike design is not utilized

– Bubbles may be too small to move the Bubbles may be too small to move the piston a significant amount for testingpiston a significant amount for testing

Gantt Chart

Attribute Option 1 Option 2 Option 3 Option 4 Option 5 Option 6

Engine Type Buoyant pistonPartially

Submergedpiston

Submergedcantilever beam

Non-submergedcantilever beam

Rotary w/ ndent

Rotary w/Volumechange

Liquid TypeDe-ionized

waterAlcohol Other ------------- ------------ ------------

Impact Plate Resistant wire Protective plate Other ------------- ------------ ------------

Power SupplyDC power

supplyDC battery AC power supply ------------- ------------ ------------

Heating Element

Straight wire Square wire Circular wire Concentric wire Metal plate ------------

Control System

Stampcontroller

ASIC chipOther

programmable chip------------- ------------ ------------

Cooling System

None Fluid reservoir Heat exchanger ------------- ------------ ------------

Movement Causality

Bubble ImpactBoiling &

Condensation----------------- ------------- ------------ ------------

Electrical System

Pulse widthModulator

(PWM)

AC circuitdesign

DC circuit design ------------- ------------ ------------

Morphological Chart

Concept Feasibility Relative

weight Concept

1 Concept

3 Concept

4 Concept

5 Concept

6 Be Portable 0.079 3 3 3 3 3 Utilize a miniature heating element

0.096 3 3 3 3 3

Be Under Budget 0.011 3 2 2 1 1 Utilize a power supply or a battery

0.073 3 3 3 3 3

Produce a mechanical oscillation

0.084 3 3 3 1 1

Create a millimeter sized engine

0.079 3 2 2 2 2

Protect the heating element

0.118 3 3 3 3 3

Control bubble growth via a control system

0.112 3 3 3 3 3

The liquid reservoir should be cooled

0 3 3 3 3 3

Theoretically prove engine design

0.107 3 3 3 1 1

Create a working engine 0.096 3 2 2 1 1 Test the engine 0.084 3 3 3 3 3 Create a lightweight design

0.062 3 3 3 3 3

Alleviate friction between piston and casing

0.082 3 4 4 4 4

Raw score ---------- 3.249 3.145 3.145 2.656 2.656 Normalized score ---------- 1 0.968 0.968 0.817 0.817

Weighted Average Analysis

Design Overview• Buoyant Piston DesignBuoyant Piston Design

– Expanding bubbles in the water cause Expanding bubbles in the water cause piston to move piston to move

– Piston-cylinder configurationsPiston-cylinder configurations • Simple to machineSimple to machine• One moving partOne moving part

– Movement of piston easily measuredMovement of piston easily measured

– Piston is buoyantPiston is buoyant• Seal is not crucial and may leak slightlySeal is not crucial and may leak slightly• Friction is reducedFriction is reduced

Detailed DesignMaterial SelectionMaterial Selection• Piston CasingPiston Casing

– Boroscilicate Glass (Pyrex)Boroscilicate Glass (Pyrex)– Stock part at McMaster - CarrStock part at McMaster - Carr– Machining - glass department is able to cutMachining - glass department is able to cut

• Piston BasePiston Base– Glass Mica Ceramic – high temp Glass Mica Ceramic – high temp – Machining - Mechanical engineering machine shopMachining - Mechanical engineering machine shop

• PistonPiston– Low Density Polyethylene (LDPE)Low Density Polyethylene (LDPE)– Less dense than waterLess dense than water– Core center to promote floatationCore center to promote floatation– Machining - Mechanical Engineering machine shopMachining - Mechanical Engineering machine shop

• ElectrodesElectrodes– Copper Wire - Stock item at McMaster-CarrCopper Wire - Stock item at McMaster-Carr

• Heater ElementHeater Element– Option 1Option 1

• Platinum wire and soldered electrodesPlatinum wire and soldered electrodes– Option 2Option 2

• Manufactured heating elements provided by Dr. KandlikarManufactured heating elements provided by Dr. Kandlikar

Pyrex Glass Casing

Ceramic Mica Base

LDPE Piston

Platinum Wire

Copper Electrodes

Piston Design

mD

mh

wp

pi 0052.0

42

37

322

3 3504.159tan3

2mE

rhrhrV bbbpp

WM

WT

TCS

VV

VtRRtHtA

max,

max,22 0))])(()([(Piston ConsiderationsPiston Considerations

–Max volume of piston Max volume of piston given density of water & given density of water & piston materialpiston material

–Obtain wall thicknessObtain wall thickness

–Obtain true piston Obtain true piston volume given drill bit volume given drill bit dimensionsdimensions

–Verify that the piston Verify that the piston still floats at appropriate still floats at appropriate heightheight

Budget

$500$500– PistonPiston– CasingCasing– BaseBase– Heater Heater – Electrical ControlsElectrical Controls

Part # Name Description Quantity Unit Cost Total Cost

1 PistonLow density Polyethelyne, 0.25" OD ± 0.018" x 8 ft., McMaster Carr

#8754K12 8 $0.67 $5.36

2 CasingPyrex tubing, 0.375" ± 0.012" x 0.218" ± 0.028" x 1 ft., McMaster Carr

#8729K33 1 $4.16 $4.163 Base Glass Mica Ceramics, 1/2" OD x 3", McMaster Carr #8499K618 1 $26.35 $26.354 Electrodes Copper wire - .032" (78 ft) (8873K17) Mcmaster-Carr 1 $3.13 $3.135 Heating Element Platinum Wire, 0.008" OD x 0.16437" 1 $0.00 $0.00

$39

Theoretical Models

Navier StokesNavier Stokes– Parallel Plates with Parallel Plates with

GravityGravity • Upper plate is moving at a Upper plate is moving at a

constant velocityconstant velocity

– Pipe Flow with GravityPipe Flow with Gravity 2

max2

R

rv

r

vx

2

1

a

yρg

x

Pa

a

μu

y

uμτ x

max

Theoretical ModelsSystem ModelsSystem Models

– Factors taken into accountFactors taken into account

– Two model types Two model types • Based upon geometrical relationshipsBased upon geometrical relationships• Based directly off of the Navier-Stokes equationsBased directly off of the Navier-Stokes equations

– 5 total models5 total models• Some neglected forces shown to be insignificantSome neglected forces shown to be insignificant• Some include all forces of the systemSome include all forces of the system

– Verification ModelVerification Model• Simplified version of the modelsSimplified version of the models

xxDD

D

DD

D

a

D

xDD

D

a

hDx

DD

DDgxm

Bkxm

pc

p

pc

ppw

pc

pipw

pc

ppwpp

pp

22

2

22

2

22

2

22

2

2

4

11

B1

B2K1

xp Mp Piston

Mw Water

xDD

DDgxx

DD

D

a

Dx

a

hD

xxDD

D

DD

D

a

Dx

DD

D

a

hDWFxm

pc

ppww

pc

ppww

ipw

pc

p

pc

ppw

pc

pipwwbww

22

2

222

2

22

2

22

2

22

2

4

Systems Model 1Systems Model 1

– Second order approximationSecond order approximation– Negligible forces are Negligible forces are

removed to simplify the removed to simplify the systems modelsystems model

– Model is setup for a known Model is setup for a known water displacementwater displacement

– Model assumes that the water Model assumes that the water moves proportional to the l moves proportional to the l displacement of the bubbledisplacement of the bubble

Theoretical Models

B1

B2

B4

xp

xw

mp

mw

B3

K1

Water

Piston

1222

44

2

22

iwpwppw

ipwppwipwpp

hgaD

xgaD

xxa

D

xa

hDgmxDghDgxm

Systems Model 2Systems Model 2

– First order approximationFirst order approximation– Neglects the viscous shear Neglects the viscous shear

force due to the air on the force due to the air on the pistonpiston

– Model assumes that the water Model assumes that the water moves proportional to the l moves proportional to the l displacement of the bubbledisplacement of the bubble

Theoretical Models

Plot comparison from Simulink Models Plot comparison from Simulink Models – Negligible factors in design considerationsNegligible factors in design considerations

Theoretical Models

Additional Theoretical Analysis

Bubble growth rateBubble growth rate– Mikic’s equationsMikic’s equations– Experimentally Experimentally

determine with high determine with high speed cameraspeed camera

A

RBtR

2

113

2 2/32/3 ttR

2

2

B

tAt

2/1212

Ja

B

2/1

)(

)(

LSatL

GfgLSatL

pT

hpTTbA

Additional Theoretical Analysis

• Heat TransferHeat Transfer– Transient heat Transient heat

conductionconduction– Semi-infinite solidSemi-infinite solid

10 ms10 ms

t

xerfc

k

xq

t

x

k

tq

TtxT oo

*2**4exp

***2

,"2

2

1

"

x

qo”

T ∞ = 25 C

T s = 400 C

WPower 495.101

WPower 495.101

Electrical System Requirements

SpecificationsSpecifications– Supply pulse signal with adjustable amplitude, duty cycle, Supply pulse signal with adjustable amplitude, duty cycle,

and frequencyand frequency– Signal must be output continuouslySignal must be output continuously– 100, 72, and 60 W signal for 10, 20 and 30 ms pulse 100, 72, and 60 W signal for 10, 20 and 30 ms pulse – Implement component protection as well as operator Implement component protection as well as operator

protectionprotection– Design for small load resistance (~0.5 Ω)Design for small load resistance (~0.5 Ω)– Flexible for different loadsFlexible for different loads

Specific Electrical Requirements

Load Power, PL

[W]Pulse Width, PW

[ms]Input Voltage,

Vin [V]Current, I [A]

100 10 7.18 14.142

72 20 6.09 12

60 30 5.56 10.956

Electrical System Concepts

Power Supply

ControlSystem

MeasureVoltage,

Current, Power

HeaterSystem

Power Supplied to

System

Power lostdue to Thermal

Resistances Pulse

AmplitudeControl

FrequencyControl

Duty CycleControl

MeasureVoltage,

Current, Power

CreatePulse Signal

Final Electrical Design

M1

Vin

0 0

Load

G1

S1

D1

D2

D4

V 5Vdd

0

D3G2

G4

G3S2

Vin

0

V 6Vdd

0

S4

S3

Load

0

M2

0

V 7

Vdd

Load

M3

M4

Vin

0 0

I

PL, VL

PL, VL

I

I

PL, VL

(a) Single NMOS (b) Single PMOS (c) Combined

22 TGSD VVk

I Current for saturation condition

Final Electrical Design Results

Input Voltage, Vin [V]

Pulse Width,

PW [ms]

Load Voltage, VL [V]

Current, I [A]

Load Power, PL [W]

Expected Load

Power, PL [W]

Percent Error [%]

5.65 10 7.0943 14.189 100.658 100 .658

5.2 20 6.0509 12.102 73.227 72 1.7

4.3 30 5.5370 11.074 61.316 60 2.2

TestingExperimental DesignExperimental Design

– Accurate high speed video Accurate high speed video analysis analysis

– Precision scalePrecision scale– A high intensity light for A high intensity light for

maximum resolutionmaximum resolution– EquipmentEquipment

• Camera: Photron Ultima APX Camera: Photron Ultima APX digital videodigital video

• Lens: Nikon AF Micro Lens: Nikon AF Micro NIKKOR 105mm 1:2.8 D with NIKKOR 105mm 1:2.8 D with optional 2x magnification.optional 2x magnification.

• Light: 600 watt halogen Light: 600 watt halogen continuous sourcecontinuous source

• Fan: High CCM 24 voltFan: High CCM 24 volt• Scale: Stainless, Scale: Stainless, ++ .01 mm .01 mm• Camera mount: standard x-y Camera mount: standard x-y

mountmount• Base: optics tableBase: optics table

Experimental Design for HS Camera Analysis of a Micro Nucleating Bubble Engine

Placement of Scale should Correspond to the CL of engine piston.

High Capacity Fan

Scale

X-Y axis

HS camera

Base

BubbleEngine

WhiteBackgroud

High OutputLight Source

Preliminary Test Conclusions

Problems encountered during preliminary testing Problems encountered during preliminary testing – More power is neededMore power is needed

– Higher resistance heaterHigher resistance heater

– Ability to solder small scale – Micro-e departmentAbility to solder small scale – Micro-e department

– Solder to withstand high temperaturesSolder to withstand high temperatures

– A more stable platformA more stable platform

– Formal setupFormal setup

– These details will be worked out in Senior Design II by the senior These details will be worked out in Senior Design II by the senior design teamdesign team

Senior Design II PlanTasks Week 11 Week 12 Week 13 Week 14 Week 15 Week 16 Week 17 Week 18 Week 19 Week 20

ResearchResearch MEMS DevicesResearch bubble bynamicsResearch patents

PlanningDelegate tasksDetermine sponsor meeting timesDetermine mentor meeting timesDetermine team meeting timesCreate work breakdown structureReview and revamp WBSCreate Gantt chartReviw and revamp Gantt ChartMission statementTechnical requirementsRisk AssessmentConcept developmentFeasibility assessment

DesignElectrical engineeringSystems engineeringFluids engineeringThermodynamic engineeringMechanical engineeringDrafting

Production & AssemblyManufacturing engineeringAssemble system

TestingDetermine what data should be recordedDetermine how to test systemCreate experimental setupRun test setupRecord dataAnalize dateGenerate data charts, tables, etc.

ReportsPeer reviewPDRCDR

Demonstrations

• Enlarged mock-upEnlarged mock-up

• MATLAB SimulationsMATLAB Simulations– Bubble growthBubble growth– Piston movementPiston movement