Ilass Book of Abstracts 2007

7/24/2019 Ilass Book of Abstracts 2007

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20YEARSOFILASS

then and now...


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ILASS-AMERICAS BOARD OF DIRECTORS

Chair Will Bachalo

Artium Technologies, Inc.

Vice-Chair Greg SmallwoodNational Research Council Canada

Treasurer Steve Londerville

Coen Company, Inc.

Secretary Doug Talley

Air Force Research Laboratory

Member-at-Large Vince McDonellUniversity of California, Irvine

Member-at-Large Michael Benjamin

Parker Hannifin Corporation

Member-at-Large Jim Drallmeier

University of Missouri, Rolla

Member-at-Large Ken Giles

University of California, Davis

Member-at-Large Corinne LengsfeldUniversity of Denver

Member-at-Large Chuck LippDow Chemical Company

Member-at-Large Rudolf SchickSpraying Systems Co.

Past-Chair Chris Edwards

Stanford University

Ex Officio Norman Chigier

Carnegie Mellon University

ILASS-AMERICAS 2007CONFERENCE

Local Arrangements Chair Rudolf Schick

Spraying Systems Co.

Program Chair Shankar Subramaniam

Iowa State University


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ILASS-07LIST OF SPONSORS

ILASS Americas thanks the following Sponsors for their generous contributions toward

the success of this years conference:

Coen Company, Inc.Steve Londerville

Chief Technical Officer100 Foster City Blvd.

Foster City, CA 94404Ph: (650) 638-0365

Fax: (650) 638-0355

[email protected]

Dow Chemical CompanyEngineering and Process

Sciences

Dr. Chuck Lipp

2301 Brazosport Blvd.,B-1226

Freeport, TX 77541-3257

Ph: (979) 238-9091Fax: (979) 238-0140

[email protected]

General Motors R&D and

PlanningScott E. Parrish

Mail Code 480-106-25230500 Mound Road

Warren, MI 48090-9055Ph: (586) 986-0692

Fax: (586) [email protected]

Goodrich CorporationTurbine Fuel Technologies

Tim GriffithChief Engineer, New Product

Development

811 4thStreet

West Des Moines, IA 50265Ph: (515) 271-7231

Fax: (515) 271-7205

[email protected]

Nektar TherapeuticsChris Varga

150 Industrial RoadSan Carlos, CA 94070

Ph: (650) 631-3100Fax: (650) 631-3150

[email protected]

www.nektar.com

Parker Hannifin

CorporationGas Turbine Fuel Systems

Division

Adel Mansour, Ph.D.R&D Technical Team Leader

9200 Tyler Boulevard

Mentor, OH 44060Ph: (440) 954-8171/8100

Fax: (440) 954-8111

[email protected]

www.parker.com/gasturbine

Procter & Gamble

Corporate EngineeringTechnologies Labs

8256 Union Centre Blvd.West Chester, OH 45069

John HechtPh: (513) 634-9625

[email protected]

Simulent Inc.

Hamideh Parizi, Ph.D.,

P.Eng.

Vice President

203 College Street,

Suite 302Toronto, Ontario M5T 1P9

Canada

Ph: (416) 979-5544

[email protected]

www.simulent.com

Solar Turbines Inc.Dr. Gareth Oskam

Applied Research LeadCombustion Engineering

P.O. Box 85376San Diego, CA 92186-5376

Ph: (619) 544-5000

Direct: (619) 544-5260

[email protected]

Spray Analysis and

Research ServicesRudolf SchickVice President

P.O. Box 7900

Wheaton, IL 60189-7900Ph: (630) 517-1409

Fax: (630) 260-7593

[email protected]

www.spray.comwww.sprayconsultants.com

Spraying SystemsCompany

Rudolf SchickNorth Ave. at Schmale Road

Wheaton, IL 60189-7900Ph: (630) 517-1409

Fax: (630) 260-7593

[email protected]

www.spray.com

Woodward, Inc.Paul G. Hicks, Ph.D.

700 North Centennial Street

Zeeland, MI 49464Ph: (616) 772-9171 x8381

[email protected]
mailto:[email protected]:[email protected]:[email protected]:[email protected]://www.goodrich.com/mailto:[email protected]%0Bwww.nektar.commailto:[email protected]%0Bwww.nektar.commailto:[email protected]://www.parker.com/gasturbinemailto:[email protected]:[email protected]://www.simulent.com/mailto:[email protected]:[email protected]:[email protected]://www.spray.com/http://www.sprayconsultants.com/mailto:[email protected]://www.spray.com/mailto:[email protected]:[email protected]://www.spray.com/mailto:[email protected]://www.sprayconsultants.com/http://www.spray.com/mailto:[email protected]:[email protected]:[email protected]://www.simulent.com/mailto:[email protected]:[email protected]://www.parker.com/gasturbinemailto:[email protected]:[email protected]%0Bwww.nektar.commailto:[email protected]%0Bwww.nektar.comhttp://www.goodrich.com/mailto:[email protected]:[email protected]:[email protected]:[email protected]


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ILASS-AMERICAS 2007

20thAnnual Conference OnLiquid Atomization and Spray Systems

ILASS-2007is the 20th Annual Conference on Liquid Atomization and Spray Systems,North and South America. Like previous ILASS conferences, it provides a venue for

industrialists, researchers, academics, and students engaged in the scientific developmentand practice of atomization and spray processes to meet and share recent developments in

the field. In addition, the 2007 conference will include a retrospective of the last 20 years

of our organization and activities and events to ensure we provide a solid technology basefor spray researchers for the next 20 years.

All aspects of atomization and spray processes will be covered, including:

Instrumentation related to sprays for drop size, drop velocity and impact, drop

concentration, patternation, film thickness, vapor concentration, etc.

Modeling of flow phenomena inside and outside of atomizers, including CFD.

Design, operation, and performance of liquid atomizers and spray systems.

Transfer processes in which liquid sprays are used, such as in spray reactors,

spray dryers, humidifiers, spray coating, spray combustion, fire fighting sprays,agricultural applications, pressure back sprays for domestic or medical use, and

atomization for metal powders and spray forming.

The ILASS-Americas 2007 Conference will include:

Tutorial sessionsrepresenting a discussion of topics of broad interest to the spray

community

Technical sessionsat which state-of-the-art research and methods are presented.

Manufacturer's exhibitsshowing the latest instrumentation and hardware in the

field. Technical committee meetingsenabling participants to engage in specific topical

discussions in areas of personal interest.


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MANUFACTURER EXHIBITOR INFORMATION

There are nine manufacturer exhibits at this years conference. They offer diagnostic andanalytical equipment, digital imaging and photography equipment, spray characterization

services and spray nozzles.

Artium Technologies, Inc.

Dantec Dynamics, Inc.

EnUrga Inc.

LaVision Inc.

Malvern Instruments

Spray Analysis and Research Services


Sympatec Inc.

TSI Incorporated

Vision Research Inc.

These companies represent the leading technologies in spray characterization,

diagnostics, imaging and analysis. Also, most have been long-term supporters of ILASS-

Americas.

Please take the time to visit the exhibits located in St. Clair Salons 1, 2 & 3 Third

Floor.


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EXHIBITORS


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Artium Technologies, Inc.is leading the way in development of the next generation ofinstrumentation for spray dynamics characterization. Founded in 1998 by key former

employees of Aerometrics, Inc., Artium has combined the latest technology in lasers,

signal processing, and computer software with our globally-recognized expertise intwo-phase flow research to produce the most compact and automated Phase-Doppler

Interferometer (PDI, also referred to as a PDPA or PDA) on the market.

Through funding from NASA GRC and the US Navy ONR we have developed a unique

flight-based Dual-Range PDI to meet a broad range of cloud and drizzle measurement

requirements. This new instrument, mounted on an aircraft or inside a wind tunnel, is

capable of making droplet size measurements simultaneously spanning a range of 1 to

1,500 m while being exposed to extreme icing conditions. The Dual-Range PDI has

been successfully demonstrated at the NASA GRC Icing Research Tunnel.

In addition to standard and custom PDI and LDV instruments, Artium Technologies also

produces a Laser-Induced Incandescence instrument for soot characterization for bothcombustion system emissions monitoring and carbon black production. Additionally

Artium is conducting research under NIH NIDDK support to apply spray technology andcharacterization to islet encapsulation and transplantation in an effort to treat Type1diabetes.

Contact Information:Will Bachalo

Artium Technologies

14660 Saltamontes WayLos Altos Hills, CA 94022-2036

Phone: 408-737-2364

Fax: 408-737-2374Email: [email protected] [email protected]

For more information please visit our web site, http://www.artium.com.
mailto:[email protected]:[email protected]://www.artium.com/http://www.artium.com/mailto:[email protected]:[email protected]


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Dantec Dynamics, Inc.develops and manufactures advanced instrumentation for

diagnostics and research into fluid dynamics, micro fluids, spray atomization, combustiontechnology and materials/components. Universities, research institutions and industry useDantec Dynamics equipment in a wide range of applications in the fields of fluid

mechanics, mechanical and civil engineering, thermodynamics, and environmental

protection.

Contact Information:

Cliff WeissmanDantec Dynamics, Inc.

200 Williams Dr.

Ramsey, NJ 07446Phone: 201-236-2466

Fax: 201-236-2469

Email: [email protected]

For more information please visit our web site, http://www.dantec.co.uk.
mailto:[email protected]://www.dantec.co.uk/http://www.dantec.co.uk/mailto:[email protected]


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Malvern Instrumentsis a global company that develops, manufactures and markets

advanced analytical systems used in characterizing a wide variety of materials, from bulk

powders to nanomaterials and delicate macromolecules. Innovative technologies andpowerful software produce systems that deliver industrially relevant data enabling

customers to make the connection between micro (eg particle size) and macro (bulk)

material properties (rheology) and chemical composition (chemical imaging). Malvernsolutions are proven in sectors from cement to pharmaceuticals and support the

understanding, improvement and optimization of many industrial processes. Extensive

industry experience and analytical expertise enable Malvern to deliver exceptionalsupport to customers worldwide.

Contact Information:Henrik Krarup or Paul Norlander

Malvern Instruments

10 Southville Rd.

Southborough, MA 01772Phone: 508-480-0200

Fax: 508-460-9692Email: [email protected] [email protected]

For more information, please visit our web site: http://www.malvern.com.
mailto:[email protected]:[email protected]://www.malvern.com/http://www.malvern.com/mailto:[email protected]:[email protected]


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Spray Analysis and Research Services, a service of Spraying Systems

Co., assists customers in a wide range of industries with spray system optimization.

This includes spray nozzle specification and selection through performance testing andComputational Fluid Dynamics (CFD); troubleshooting problems in existing spray

operations; and developing new ways to utilize spray technology. Our services

include research, consulting, computer modeling, spray characterization/performance

testing, proof-of-concept studies and spray nozzle/header prototype development. SprayAnalysis is home to the world's largest and most sophisticated spray laboratories and

conducts educational seminars on spray technology seminars twice annually for

individuals seeking an advanced understanding of the science behind atomization andsprays.


Rudolf Schick or Elizabeth KucharzSpray Analysis and Research Services

P.O. Box 7900

Wheaton, IL 60189Phone: 630-665-5000

Fax: 630-260-7593

Email: [email protected] [email protected]

For more information please visit our web site: http://www.SprayConsultants.com
mailto:[email protected]:[email protected]://www.sprayconsultants.com/http://www.sprayconsultants.com/mailto:[email protected]:[email protected]


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Sympatecspecializes in Laser Diffraction instruments for measurement of droplet size

distribution in sprays. Since our beginning days in the Harz Mountains of Germany in

1984, we have been well known for high quality laser diffraction technologies. Sympatecis still owned and managed by the 4 PhD Physicists that founded the company, which

explains our no-nonsense approach to physics and hardware.

Our HELOS/VARIO can measure from 0.25um to 3,500um, with several innovative

features to guarantee the best possible results. We offer a choice of 7 measurementranges (lenses), to concentrate on the droplet size range you are most interested in, with

the best possible sensitivity. Our patented beam expander offers 3 beam sizes: 2mm,13mm, and 26mm, for the best balance of laser intensity and particle count. Construction

is thick extruded aluminum mounted to an X-95 backbone, with a 5mW HeNe laser and

auto-focusing of the 31 element detector.

Contact Information:Alan Pieper or

9A Princess Rd.

Lawrenceville, NJ 08648Phone: 609-844-1020

Fax: 609-844-1225


For more information, please visit our web site: http://www.sympatec.com.
mailto:[email protected]://www.sympatec.com/http://www.sympatec.com/mailto:[email protected]


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TSI Incorporateddesigns and manufactures precision instruments used tomeasure sprays, flows, particulates, and other key parameters in environments the world

over. TSI serves the needs of industry, governments, research institutions, and

universities, with applications ranging from pure research to primary manufacturing. OurPDPA System, like every TSI instrument, is backed by unique technical expertise and

outstanding quality.

TSI instruments are used around the world. They are found on mountaintops and oceanbeaches. They are used in submarines, office towers, factories, and schools. They operatein laboratories and on farms. They went to the North and South Poles and served on

desert battlefields. They flew in the space shuttle, and one even went to Mars to measure

the velocity and direction of Martian winds.

TSI instruments help people investigate, identify and solve measurement problems. They

often play a pivotal role in designing or modifying production processes or energy

conversion systems. They are used in industrial, university, and government facilities inevery industrialized country, in nearly every major industry and technical discipline,

often in crucial research or control situations.

TSI has a worldwide presence with over 800 dedicated employees working in facilities in

North America and Europe and Asia. Our corporate sales and service offices (St. Paul,Minnesota, USA; Aachen, Germany; Marseille, France; Arlanda Stad, Sweden; High

Wycombe, United Kingdom; Beijing, China, and Bangalore, India) provide regional

customer support. We also maintain a network of knowledgeable manufacturers

representatives and distributors to provide local support worldwide.

Contact Information:Joe Shakal or Dr. Stamatios Pothos

TSI Incorporated500 Cardigan Rd.

Shoreview, MN 55126Phone: 651-490-2856

Fax: 651-490-3824

Email:[email protected]@tsi.com

For more information, please visit our web site: http://www.tsi.com
mailto:[email protected]:[email protected]://www.tsi.com/http://www.tsi.com/mailto:[email protected]:[email protected]


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Vision Research Inc. designs and manufactures high-speed digital imaging systems used

in measurement and entertainment applications. Their broad line of cameras, marketed

under the Phantom trademark, span a variety of application domains including

Defense, Automotive, Engineering, Scientific and Medical Research, Industrial andCommercial, Sports and Entertainment, and Digital Broadcast and Cinematography. The

Phantom product family has been recognized for their innovations in high-speed digital

camera technology and sensor design receiving numerous research and developmentawards.

Vision Research prides itself on the light sensitivity, the high resolution and image

quality of their cameras; the robust yet easy to use software interface; and the reliabilityand versatility of their Phantom camera family which continue to be the benchmark for

all other high speed digital camera manufacturers.

VRI cameras add a new dimension to the sense of sight, allowing the user to see details

of an event when itstoo fast to see, but too important not to

.


Tim Mills or Ray MaguireVision Research, Inc.

100 Dey Rd.

Wayne, NJ 07470Phone: 248-546-0251


For more information please visit our web site, http://www.visionresearch.com
mailto:[email protected]://www.visionresearch.com/http://www.visionresearch.com/mailto:[email protected]


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11:20 amModeling Sprays for Lean PremixPrevaporized Fuel Injection in GasTurbinesGareth Oskam, SOLAR Turbines Inc

An implic it implementat ion ofsurface tension in finite volumemodels for two-phase flowsMehdi Raessi, Javad Mostaghimi,

Markus Bussmann, University of Toronto

11:45 am

Effect of Fan Air Flow Rate on theSpray DistributionM. Choi - PCTS, Inc., R. J. Schick andK. C. Cronce, Spraying Systems Co.

Conservative Level Set/Ghost FluidMethod for Simulating Primary

AtomizationOlivier Desjardins, Marcus Herrmann,and Heinz Pitsch Stanford University

12:10 pm Annual Business Meeting, Exhibits, PostersLunch Room: Grand Ballroom B & CExhibition Room: St. Clair Salons 1, 2 & 3

(Sponsored by Goodrich Corporation)

SESSION 3A

SPRAY MODELING(Room: Lakeshore East)

SESSION 3B

SIMULATIONS(Room: Lakeshore West)

Chairpersons: Rolf D. Reitz,University of Wisconsin-Madison, andand M.F. Trujillo, Penn StateUniversity

Chairpersons: Nasser Ashgriz,University of Toronto, and Ravi K.Madabhushi, United TechnologiesResearch Center

1:30 pmDevelopment of a Next-GenerationSpray and Atomization Model Usingan Eulerian-LagrangianMethodologyWei Ning, Rolf D. Reitz, University of

Wisconsin-Madison, Andreas Lippert,and Ramachandra Diwakar, GeneralMotor Corporation

CFD Analysis for NOx-Contro l inRefineryK. Brown, R. Schick, K. and R. Gardner,Spraying Systems Co


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FRIDAY - MAY 18, 2007

7:15 am BreakfastRoom: St. Clair Meeting Room Pre-Function Area(Sponsored by Spray Analysis and Research Services)

SESSION 1A

DIESEL(Room: Lakeshore East)

SESSION 1B

JET ATOMIZATION(Room: Lakeshore West)

SESSION 1C

FIRESUPPRESSION

(Room: Grand Ballroom A )

Chairpersons: JinWang, Argonne NationalLab, and James E.McCarthy, Jr., EatonCorporation

Chairpersons:AntonioCavaliere, UniversityFederico II, and James A.Drallmeier, University ofMissouri Rolla

Chairpersons: JerryHagers, SprayingSystems Co.

8:00 am

Fuel Effects on theSpray and CombustionProcesses Within anOptical HSDI DieselEngineTiegang Fang, Chia-fonLee, University of Illinoisat Urbana-Champaign

Breakup of a laminaraxisymmetric l iquid jetSadegh Dabiri, William A.Sirignano, University ofCalifornia, Irvine, DanielD. Joseph, University ofMinnesota

Extinguishment ofHorizontal Wood SlabsFire by a Water SprayTri Poespowati,The Institute of NationalTechnology, Malang -Indonesia

8:25 am

ImprovedMethod to DetermineSpray Axial VelocityUsing X-RayRadiography

Alan Kastengren, F.Powell, Yujie Wang,Kyoung-Su Im, Xin Liu,Seong-Kyun Cheong andJin Wang, ArgonneNational Laboratory, andThomas Riedel, RobertBosch, GmbH

On the Linear Stabili tyof Compound CapillaryJetsMaksud (Max) Ismailov,Stephen D. Heister,Purdue University

Water MistSimplification Effectson Fire SuppressionModeling: A Challengeto the IndustryGeoff Tanner,Keith Knasiak,Spraying Systems Co.


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SESSION 4A

SPRAY MODELING(Room: Lakeshore East)

SESSION 4B

INDUSTRIAL(Room: Lakeshore West)

SESSION 4C

BIODIESEL(Room: Grand Ballroom A)

Chairpersons: ShankarSubramaniam, IowaState University

Chairpersons:JohnHecht, Procter andGamble

Chairpersons: YangbingZeng, General MotorsCorporation

11:35 am

Intra-Parcel CollisionModelScott Post,Bradley University

Spray Velocity andDrop SizeMeasurements inVacuum Conditions

Renaud Lecourt, ONERAJohan Steelant,ESA-ESTEC

Spray Characteristicsof an Airblast Atomizeron Biodiesel BlendsC. R. Krishna and

Thomas Butcher, EnergyResources Division,Brookhaven NationalLaboratory

12:00 noon

Droplet CollisionModeling in Multi-Dimensional SprayComputations

Achuth Munnannur,Prof. Rolf D. Reitz,University of Wisconsin-Madison

In-line nozzlemonitoring systembased on recursiveleast squares

De Ketelaere,Biostatistics and Sensors(MeBioS), Wulteputte, L.,

AutoJet TechnologiesB.V.B.A. Anthonis, J.,Biostatistics and Sensors(MeBioS)

Optimization ofAirblast Atomizationfor Reducing PollutantEmissions from a

Recuperated GasTurbine EngineOperated on BiodieselChristopher T. Brown,Ulises M. Mondragon,Vincent G. McDonell,Energy ResearchConsultants

12:25 pmEnd of Conference


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ABSTRACTS


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IILASS Americas 20th Annual Conference on Liquid Atomization and Spray Systems, Chicago, USA, May 2007

Modeling Requirements for Large Eddy Simulation of Multi-Component Fuel

Two-Phase Flows Using Continuous Thermodynamics

Laurent C. Selle1 and Josette Bellan,1,2

California Institute of Technology1, Pasadena CA 91125Jet Propulsion Laboratory2, California Institute of Technology, Pasadena CA 91109-8099

Abstract

The Large Eddy Simulation (LES) equations for multi-component (MC) fuel two-phase flow are derivedfrom the Direct Numerical Simulation (DNS) equations by filtering the DNS equations using a top-hatfilter. The filtered equations contain two categories of subgrid-scale (SGS) terms that must be modeled: (1)SGS terms and (2) terms representing the LES assumptions. In contrast to single-component (SC) fuels,it is shown that two LES formulations, rather than a single one, are possible, and these formulations arenot equivalent. Assumptions not present in corresponding SC LES equations are examined and assessed.Criteria are proposed to select the formulation best suited for LES. These criteria are used in conjunctionwith evaluations based on a DNS database and lead to the final LES equations. This analysis represents theprecursor to a future study for modeling the MC LES equations.

Wednesday, Session 1B - 1


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ILASS Americas, 20thAnnual Conference on Liquid Atomization and Spray Systems, Chicago, IL, May 2007

Comparisons between a High Speed Direct Injection Engine Operating with Biodiesel and

Petroleum Based Diesel

W. L. Cheng1, V. L. Stringer

1, J. McCrady

2, A. Hansen

2and C. F. Lee

1*

1Department of Mechanical Science Engineering

2

Department of Agricultural and Biological EngineeringUniversity of Illinois at Urbana-Champaign

Urbana, IL 61801, USA

Abstract

Numerical calculations using the KIVA 3V code developed by Los Alamos National Laboratory are performed to

compare the operation of a small bore high speed direct injection engine using biodiesel and diesel fuels. Several

modifications to the code are made to improve its capability with biodiesel simulations. These include the Kelvin-Helmholtz/Rayleigh-Taylor model for describing the droplet breakup process and the Shell model, calibrated for

biodiesel and low temperature combustion. Formation of nitrogen oxide is described by the extended Zeldovich

mechanism. The fuel library is expanded to include properties of soybean biodiesel using BDProp. The modified

KIVA code is shown to accurately predict the major combustion characteristics, include the peak combustion tem-

perature, heat release rate and ignition timing, so is nitrogen oxide emission. The simulations show that biodiesel

has a longer ignition delay and lower peak combustion pressure. A longer combustion process is observed in con-ventional diesel. Experimental data shows that diffusion flame may exist when biodiesel is injected at 3 after top-

dead-center, even though the main combustion process can be described as HCCI from the single peaked heat re-

lease curve. Formation of nitrogen oxide is correctly predicted by the modified KIVA code also. The formation ofnitrogen oxide, for both biodiesel and petroleum based diesel fuel, are characterized by rapid initial formation, then,

frozen at the maximum value as in the extended Zeldovich model. Deferring injection time reduces the production

of nitrogen oxide significantly. The combustion process starts in the later part of the cycle with delayed fuel injec-tion. This allows the fuel vapor-air mixture to better mix upon ignition, thus, preventing high temperature flame.

The cooler ambient temperature due to expansion also assists in inhibiting formation of the species. Reduction of

over 90% is observed when fuel injection is delayed from 335 to 363.

*Corresponding author



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Visible Light Extinction Tomography for Dense Sprays

Yudaya Sivathanu and Jongmook LimEnUrga Inc., 1291-A Cumberland Avenue, West Lafayette, IN 47906

This study examines the feasibility of visible light extinction tomography for understanding the structure ofdense sprays. Some sample results obtained during the study are reported.

IntroductionLaser sheet extinction tomography has become

a popular technique used in the quality assuranceof injectors. Data from laser sheet extinctiontomography that have been presented in the pasthave focused on oil and water sprays with peakpath integrated absorptances of approximately60% [1,2]. This present study extends the use oflaser extinction tomography to sprays that haveextinction greater than 90%.

TheoryLaser extinction tomography involves

measurement of path integrated extinction frommultiple view angles. The path integratedextinction is deconvoluted using the MaximumLikelihood Estimate (MLE) method [3]. Thedeconvolution provides the local extinctioncoefficient. For a cloud of droplets from a non-absorbing spray, the liquid surface area per unitvolume, is identical to the local extinctioncoefficient, provided the drop sizes are muchgreater than the wavelength of light.

Experimental ApparatusThree different nozzles were used in this study.

The first is a large industrial nozzle, with an oil flowrate of 375 lbs/hr. The second is an aircraft enginenozzle with a water flow rate of 1200 lbs/hr. Thelast is a ketchup dispenser. Path integratedextinction for the first two nozzles were obtainedusing the SETscan

OP-600 patternator. The

OP2-200 patternator was used to obtain data fromthe ketchup dispenser.

ResultsPath integrated extinction measurements from

the first two nozzles are shown in Fig. 1. Only onesix view angles is shown for the figures. Theconvergence of the algorithm to the measuredvalues is within 0.5%. Therefore, there is a highdegree of confidence in the results. Similar

agreement between the measurements and thecalculations were obtained for the ketchup jet,which had a peak absorptance value of 0.99.

The contour plot of surface area densities for thewater spray is shown in Fig. 2. The hollow conebehavior of the nozzle is evident, with the centervalue being less than 5% of the peak.

Sample characteristics obtained for threeketchup nozzles are shown in Table 1. Even foressentially obscuring jets, small differences in

nozzle performances can be obtained. Based onthe study, it can be concluded that the methodworks reasonably well for very dense sprays.

Figure 1. Measured and deconvoluted path integratedabsorptance for the oil and water sprays.

Figure 1. Contour map of surface area densities for thewater spray.

Table 1: Characteristics of ketchup nozzles

Parameter Nozzle 1 Nozzle 2 Nozzle 3

Total surface

area (mm2)

11.55 12.06 9.902

Patternation no.(12 sector) 0.230 0.254 0.279

Maximum

density (mm-1

)

2.166 2.237 1.834

References[1] Lim, J., Sivathanu, Y., Narayanan, V., and Chang,

S., Atomization and Sprays, 13:27-43 (2003).[2] Lim, J., and Sivathanu, Y., Atomization and Sprays

15:687-698 (2003).[3] Vardi, Y., and Lee, D., J. R. Statist. Soc. B, 55:569-

612 (1993).

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Quantitative Measurements of Sauter Mean Diameter and Volume Fraction inDense, Transient, Diesel Sprays

T. E. Parker*and J.E. Labs

Engineering Division, Colorado School of Mines, Golden, CO 80401

This abstract summarizes a measurement technique that provides time and spatially resolved droplet size and vol-

ume fraction measurements within transient, optically dense diesel sprays. Results are quantitative and can be usedin repeatable systems to build up a pseudo-image, in a scattering plane, of size or volume fraction results.

IntroductionMeasurements near the fuel injector outlet are diffi-

cult to make due to the high number densities of drop-

lets and the transient nature of the spray event. Thispaper summarizes work with infrared laser probes to

produce spatially and temporally resolved Sauter mean

diameter (SMD) and liquid volume fraction data from

the spray interior. Details of this measurement can befound in the literature;

1 extensions that allow applica-

tion of the measurement in very dense regions are alsodescribed.

2This work is the culmination of many years

of effort and complements the more recent efforts fo-

cused on imaging measurements of the dense spray(note that two significant techniques have emerged:

ballistic imaging3and X-ray extinction

4).

Experimental ApparatusExperiments have been conducted in a system ca-

pable of producing high pressures and temperatureswhile providing optical access; this system is coupled to

a high pressure, single orifice diesel spray nozzle and

the most relevant experiments have been conducted at

initial temperatures of 873 K and 12.5 atm.

Figure 1. Measurement layout for infrared dense spray meas-urements.

Optical measurements were based upon dual wave-

length coaxial beam scattering and extinction and opti-cal access was provided normal to the injector axis in

two orthogonal directions through barium fluoride win-

dows (chosen for their visible and infrared transmittanceproperties). Figure 1 depicts a schematic of the meas-

urement layout. This system used a tunable CO2 laser

operated at 9.27m and an Nd:Yag laseroperated at the

fundamental frequency (1.06m), both cw, to produce

co-aligned probe volumes. The combination of extinct-

Figure 2. Droplet size results for the combusting spray.

tion and scattering signals is used with the known scat-

tering response from droplets to invert the acquiredsignals into sauter mean diameter and volume fraction.

ResultsResults from multiple, yet identical, events have been

used to construct two-dimensional contour plots of theSauter mean diameter and volume fraction within the

spray. These plots are based on data obtained through-out the data acquisition grid (axial locations in 5 mm

increments and radial locations in 0.3 mm increments);

results are presented as contour plots of SMD and liquid

volume fraction with one contour plot for each 100 sin the spray development. Figure 2 is a contour plot of

the SMD as a function of axial and radial position for

the times 0.55 ms, 2.05 ms, and 3.45 ms (which repre-sent a 0.1 ms time average during spray development,

steady state and spray dissipation). Full movies for allcases examined can be viewed online.

References

[1] Labs, J. and Parker, T.E.,Atomization and Sprays,16, 7, pp. 843-855 (2006).[2] Labs, J. and Parker, T.E.,Applied Optics, 44, 28,

pp. 6049-6057(2005).[3] Linne, M., Paciaronni, M., Hall, T. and Parker, T.E.,

Experiments in Fluids, 40, 6, pp. 836-846 (2006).[4] MacPhee, A. G., et al., Science, 295, pp. 1261-

1263, (2002).[5] http://www.begelhouse.com/video/6a7c7e10642258cc/X.avi,

where X is smd_movie_cold, smd_movie_comb,vf_movie_cold, vf_movie_comb.

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Visualizing Dense Sprays byUltrafast X-ray Radiography and Phase-Contrast Imaging

Jin WangAdvanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA

Dense sprays of direct-injection diesel and gasoline fuels in the near-nozzle region have been success-fully visualized by s and sub-s x-ray radiography and phase-contrast imaging.

IntroductionThe detailed analysis of the fuel sprays has

been well recognized as an important step for op-timizing the operation of internal-combustion en-gines to improve efficiency and reduce emissions.However, the structure and dynamics of highlytransient and dense fuel sprays have never beenfully visualized in the near-nozzle region due tomany technical difficulties associated with conven-tional visible-light-based visualization techniques.By using intense x-ray beams from synchrotronradiation sources, the fine structures and dynamicsof the fuel spray core can be elucidated with ul-trafast x-ray radiography and phase-contrast imag-ing.

MethodsFor x rays in most materials, the index of refrac-

tion is less than unity as n =1 i, where

and refer to the refractive index decrement and

the absorption index of the x rays in the medium,respectively, and are extremely small quantities of

magnitude


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Electrostatically Assisted Fuel Injection and Charged Droplet Combustion

E. K. Anderson1, A. P. Carlucci

2, A. De Risi

2, and D. C. Kyritsis

1*

1Department of Mechanical Science and Engineering

University of Illinois at Urbana-Champaign

Urbana, IL 61820 USA2Department of Engineering for Innovation

University of Lecce

Lecce, Italy

Abstract

A gasoline fuel injector was modified to allow the induction of electrostatic charge to the spray as an additional

means of controlling fuel dispersion. Fraunhofer diffraction measurements were made on the sprays, and comparing

average droplet size for ten sprays, it was found that the standard deviation was cut in half by electrostaticassistance, and the relative span factor of an individual spray was reduced by approximately 10%. E10 droplets at

various charge levels were ignited and the flame was recorded with a high speed camera. Morphological differences

between different levels of charge were dramatic.


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A Model for Deformation of Liquid Jets and Droplets Subjected to Gaseous Flows

A. Mashayek1, A. Jafari

2and N. Ashgriz

2*

1Department of Mechanical and Aerospace Engineering

University of California San Diego, La Jolla, CA 92093-0411, USA2

Department of Mechanical and Industrial EngineeringUniversity of Toronto, 5 Kings College Road, Toronto, ON, M2M 2G5 Canada

Abstract

An analytical model is used to calculate the deformation and spreading of the two-dimensional and axisymmetric

liquid drops in a gas stream. The model is based on the expansion of the Navier-Stokes equations in a series of small

parameters. The zeroth and first order terms correspond to the deceleration and deformation of the liquid body re-

spectively. The axisymmetric formulation is used for calculating the spreading of the spherical droplets while thetwo-dimensional formulation is used for predicting the spreading of the liquid jets cross section in cross flows.

There is good agreement between the present calculations and experimental data.




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ILASS Americas, 20thAnnual Conference on Liquid Atomization and Spray Systems, Chicago, USA, May 2007

___________________*Corresponding author

MODELING THE EFFECT OF MOMENTUM FLUX RATIO ON THE WAKE

VELOCITY CHARACTERISITICS OF A LIQUID JET IN CROSSFLOW

Marco Arienti and Ravi K. Madabhushi*

United Technologies Research Center, East Hartford, CT 06108

ABSTRACT

The spray velocity characteristics in the wake of a liquid jet in crossflowing air are studied numericallyusing the volume of fluid (VOF) method. Simulations are carried out at different liquid-to-gas momentum

flux ratios to understand the effect of jet injection conditions on droplet velocity profiles. The effects of jet

wake on droplet velocity are correctly captured in the calculations: (1) a decrease in droplet streamwise(crossflow direction) velocity away from the injection plane due to the increasing blockage of the

spanwise-flattening jet and, (2) the subsequent increase in droplet velocity as jet bending becomes

significant due to increasing momentum exchange with the crossflow. The main result from this paper isthe finding that the observed increase in droplet streamwise velocity with injection velocity at the same

crossflow conditions can be explained by assuming a dependence of primary breakup droplet size on

injection velocity using empirical correlations.

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Effect of Fan Air Flow Rate on the Spray Distribution

M. Choi*

PCTS, Inc.

P.O. Box 633, Montgomeryville

PA 18936 USA

R. J. Schick and K. L. Cronce

Spray Analysis and Research ServicesP.O. Box 7900

Wheaton, IL 60189-7900 USA

AbstractIn tablet film coating application, spray distribution plays a critical role in helping achieve a uniform coating [1].

The primary role of fan air in this application is to shape the spray into a flat fan, so that the liquid is distributed

evenly on the target.

In this study, the effect of fan air flow rate on air velocity, droplet size, and deposition distributions was examined atvarying atomizing air and water flow rates, and for various sizes of commonly used external-mix two fluid atomiz-

ers. Hot-wire anemometer, Phase-Doppler, and gravitational method were used to measure air velocity, droplet size,

and deposition distributions, respectively at 6, 12, and 18 distances from the nozzles.

The results showed that air velocity, droplet size, and deposition distributions followed the same trend in that, as the

fan air increased from zero velocity, the shape of the distribution changed from Gaussian to flat to bifurcated distri-

bution. However, the width of the distribution was consistently wider for the deposition distribution compared tothe air velocity distribution, and the bifurcation occurred at slightly lower fan air flow rates for the deposition distri-

bution compared to the air velocity distribution.

While the correlation is still being developed, the implication of this finding is that air velocity analysis, which issimpler and more cost-effective than Phase-Doppler analysis, may be used to determine the bifurcation limits of the

spray.


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CFD Analysis for NOx-Control in Refinery

K. Brown and R. Schick

Spray Analysis and Research Services

P.O. Box 7900

Wheaton, IL 60189-7900 USA

R. Gardner


P.O. Box 7900

Wheaton, IL 60189-7900 U.S.A

Abstract

In the refining business there is a large push by the industrial community to reduce emissions. Greenhouse gases as

well as nitrous oxides (NOX) and sulfur dioxide (SO2) are the targeted pollutants. Governmental legislation outlined

by the Environmental Protection Agency (EPA) through its MACT II guideline is a major thrust.

In refineries, downstream of process gases - cyclones, scrubbers, bag filter houses, and electrostatic precipitators are

used to reduce emissions prior to gases venting to the atmosphere. The operation of this equipment is highly

dependent on the humidity and temperature of the gases and so careful control must be integrated. The process of

controlling the gas temperature and humidity is referred to as the gas conditioning process. Spray nozzles are an

important factor in this process; spray nozzles add value by providing controlled volumes of liquid with predictable

drop size and consistent spray coverage. Knowing these values remains vital for the optimization of gas

conditioning processes.

In addition, the all-important placement of nozzles is often times misunderstood and therefore inaccurate. While

immense care is taken to optimize placement, this often leads to failure due to the inability to predict spray

performance in the application environment. This process can be facilitated by using computational fluid dynamics

(CFD).

In this case study, CFD is used to identify problem areas that would have caused wetting on walls and more

importantly eroded metal sections from the heavily catalyst-laden process stream. In the end, adjustments weremade to original nozzle placement suggestions in order to optimize the gas conditioning process.

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Heat transfer between cryogen droplet and epoxy skin model

J. Liu and G. Aguilar*

1Department of Mechanical Engineering

University of California-RiversideRiverside, CA 92521

Abstract

Cryogen Spray Cooling (CSC) is an auxiliary procedure that pre-cools the epidermis during Laser DermatologicSurgery (LDS) to avoid non-specific epidermal thermal damage. To better understand the heat transfer mechanisms

during and after CSC, we first observe the heat transfer between a single and multiple cryogen (R134a) droplets and

an epoxy skin model. To avoid the effect of boiling of the cryogen drop during the impact process, we conduct ourexperiments within a chamber pressurized above the saturation pressure of R134a at room temperature. Single or

multiple cryogen droplets impact onto a skin model instrumented with a fast-response thin-film thermocouple. The

surface temperature variations are recorded and used to calculate surface heat fluxes. Using this setup, we analyzethe effect of initial surface temperature, droplet size, droplet velocity and multiple droplet impact frequency on the

overall cooling efficiency and establish the similarities and differences of these parameters with those measured for

CSC.


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Improved Method to Determine Spray Axial Velocity Using X-Ray Radiography

Alan L. Kastengren, Christopher F. Powell

Center for Transportation Research

Argonne National Laboratory

Argonne, IL 60439 USA

Thomas Riedel

Diesel Systems - Commercial Vehicles/ Engineering Systems ApplicationRobert Bosch GmbH

Stuttgart, Germany

Seong-Kyun Cheong, Yujie Wang, Kyoung-Su Im, Xin Liu, and Jin Wang

Advanced Photon Source

Argonne National LaboratoryArgonne, IL 60439 USA

Abstract

X-ray radiography is a technique that has provided important insights into the structure and behavior of diesel spraysin recent years. An analysis method has been developed to derive the mass-averaged axial velocity from the radiog-

raphy data. This determination, however, was found in previous work to be subject to a significant degree of noise,

limiting the usefulness of the analysis. In this work, a fitting procedure is implemented to substantially improve the

results from this analysis. After demonstrating the superiority of the fitting method over the previously used

method, the results of the analysis for four different sprays from light-duty diesel common rail injectors will be ex-amined. Sprays from two different single-hole axial tip geometries (hydroground and non-hydroground) and two

injection durations (400 s and 1000 s) have been used. The injection pressure is 250 bar, with injections into N2

at atmospheric pressure and room temperature. The maximum velocity seen in the long-duration sprays is 20-25%less than the Bernoulli velocity, though it appears that the injectors have not yet reached steady state at the end of

the data record. For the 1000 s duration sprays, the trends of spray axial velocity with axial position are quite simi-

lar between the two nozzles. This is surprising considering that the cone angle of these sprays is quite different.Calculations of the spray momentum show that the spray from the non-hydroground nozzle has more total axial

momentum than the spray from the hydroground nozzle. For the 400 s duration injections, the hydroground nozzlehas the greater momentum, possibly due to differences in the injector current histories between the non-hydroground

and hydroground nozzle sprays.

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ILASS Americas 20th Annual Conference on Liquid Atomization and Spray Systems, Chicago, IL, May 2007

Predicting Breakup Characteristics of Liquid Jets Disturbed by Practical

Piezoelectric Devices

M. Rohani, D. Dunn-Rankin, and F. Jabbari

Department of Mechanical and Aerospace Engineering

University of California Irvine, Irvine, CA 92697

Abstract

In this paper, we study the breakup characteristics of a jet of liquid. To break a capillary jet into droplets, a

piezoelectric is often used to generate disturbances growing along the jet. Rayleighs linear theory predicts

that uniform droplets are produced when the jet is p erturbed by a single wavenumber disturbance. However,

studies limited to linear behavior are unable to predict how the jet behaves if it is subjected to a multiple-

frequency input. Measurements of an actual piezoelectrics dynamics show that driven with single frequency

harmonic signal, it disturbs the jet with three output sine waves: one steady state response and two very

lightly damped modes corresponding to the structural resonances of the device. In this paper, we study the

interaction of these output waves to estimate the range of frequencies where irregularity effects are likely

to occur on the surface of the jet that might lead to nonuniform droplet formation. Control strategies

designed to eliminate these unwanted dynamics can then retain uniform breakup over a wide range of input

frequencies.



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Independent Control of Flow Rates and Droplet Size Spectra from Fan Nozzles Using a

Single Actuator

D. K. Giles*and D. Needham

Department of Biological & Agricultural Engineering

University of California-DavisDavis, CA 95616-5294 USA

Abstract

In processes were sprays are generated using pressure or orifice nozzles, the volumetric flowrate and resulting drop-

let size spectra are critical parameters. With passive nozzles, the flowrate and droplet size spectrum are coupled and

changes in one are coincident with changes in the other. Pulse width modulation of flow through nozzles has been

developed as a means to control flowrate independently of droplet size; however, this technique requires a separate

system and actuator for liquid pressure and droplet size control. This paper reports the development of a methodand prototype where a single actuator is used to provide real time control of flowrate through and pressure into a

spray nozzle. A direct-acting, direct-current solenoid valve was controlled using a complex waveform including a

burst current for initiating movement of the valve plunger, a high frequency PWM signal for plunger positioning and

an off period. The waveform was repeated at a 10 Hz rate. Manipulation of the duration of the high frequency

PWM signal provided control of the pressure drop across the valve and, consequently, supply pressure to the nozzlewhile the duration of the PWM signal, in relation to the off time, provided the temporally-averaged flowrate. The

prototype was tested with 8002 and 8006 flat fan nozzles over a pressure range of 125 to 625 kPa and a f lowrate

range of of 240 to 1080 ml/min (8002 nozzle). A droplet size (Dv0.5) range of 150 to 250 m was obtained. While

additional design and development work is necessary to bring the technique to commercial use, the preliminary data

establish the feasibility of the method.


Introduction

In agricultural spraying from mobile equipment,

the flow rate through a nozzle is important in order to

deliver the specified amount of active ingredient to aspecified area. The proper flow rate is often a function

of nozzle spacing on a spray boom and vehicle speedover ground. Past studies have shown that nozzle flow

rate can be accurately manipulated by pulse width

modulation (PWM) of a solenoid valve, with the duty

cycle of the drive signal being linearly related to the

average flow rate [1, 2, 3, 4]. This allows flowrate to

be manipulated without changes in droplet size spectra.

The liquid pressure supply to a spray nozzle can

also be an important issue because it regulates the aver-

age and distribution of sizes of the droplets being deliv-

ered. Wind speeds, chemical type, and plant canopyoften determine the droplet size that is required. Tradi-

tionally, pressure in an agricultural sprayer has been

regulated on a total system basis by opening and clos-

ing an inline or a bypass valve in the fluid supply sys-tem.

Because the desired flow rate and the desired pres-

sure are derived from different parameters, control of

the two independently would be beneficial to the appli-

cator. Additionally, because agricultural spraying is a

low margin business, and because spray components

are typically expensive, independent control of both

pressure and flow with a single actuator would be de-

sirable.The flow through a valve and the pressure across

the valve in steady-state are usually related, where flowis a function of the square root of pressure. However, if

the valve is controlled with a complex metering func-

tion, average flow rate and instantaneous pressure

(droplet size) may be controlled independently.

Design Strategy

The system described in this paper utilized a modu-

lated square wave driving a solenoid valve to control

pressure and flow. The duty cycle of the high-

frequency modulation was used to throttle a solenoidpoppet valve to manipulate outlet pressure. The low-

frequency pulse duty cycle was used to meter the aver-

age flow rate by enabling/disabling the instantaneous

flow rate that resulted from the outlet pressure. Thus,the solenoid drive signal allowed decoupled control of

droplet size (pressure) and average flow rate.

Typically, a pulsing solenoid valve is designed to

be actuated to a fully open state when energized (as-

suming a normally closed valve). Therefore, the square



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ILASS Americas 20th Annual Conference on Liquid Atomization and Spray Systems, Chicago, IL, May 2007

Subcritical and Supercritical Nanodroplet Evaporation:

A Molecular Dynamics Investigation

E. S. Landry, S. Mikkilineni, and A. J. H. McGaughey

Department of Mechanical Engineering

Carnegie Mellon University, Pittsburgh, PA 15213-3890

Abstract

Molecular dynamics simulations are used to investigate the subcritical and supercritical evaporation of aLennard-Jones (LJ) argon nanodroplet in its own vapor. Using a new technique to control both the ambienttemperature and pressure, a range of conditions are considered to define a transition line between subcriticaland supercritical evaporation. The evaporation is considered to be supercritical if the surface temperatureof the droplet reaches the LJ argon critical temperature during its lifetime. Between ambient temperaturesof 300 K and 800 K, the transition from subcritical to supercritical evaporation is observed to occur at anambient pressure 1.4 times greater than the LJ argon critical pressure. For subcritical conditions, the droplet

lifetimes obtained from the simulations are compared to independently predicted lifetimes from the D2 law.

Corresponding Author. [email protected]


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Discrete Phase Based Method (DPM) of Modeling Sheet Formation and Breakup

1A.Sarchami,

1N.Ashgriz*,

2H.N.Tran

1Mechanical and Industrial Engineering Department,

2Chemical Engineering Department,

University of Toronto, Toronto, Canada

Abstract

A discrete particle model (DPM) is used to simulate the spray formation by a splash plate nozzle. In a splash plate

nozzle, a continuous liquid jet impinges on a solid surface and spreads radially forming a liquid sheet. Later, this

liquid sheet breaks into small droplets forming the spray. In the present model, instead of a continuous liquid jet,

streams of droplets impinge on the splash plate and breakup into smaller droplets. Droplet diameter and velocity

distributions after impingement are determined based on the liquid sheet thickness and velocity distribution obtained

from an invicid theory for a jet impingement. This model is implemented in Kiva3V to determine the droplet size

and velocity distribution further downstream of the nozzle. Droplet diameter and velocity are now functions of

initial droplet impingement angle and the distance from the impinging point. To refine the jet impingement model

and use a more accurate sheet thickness and velocity distributions, DNS simulation of impinging jet on a plate has

also been performed.

* Corresponding Author:[email protected]

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A Preliminary Investigation of Flow Scaling for Injector Characterization

P. Andrew Corber*

Gas Turbine LaboratoryInstitute for Aerospace Research

National Research Council of Canada

1200 Montreal Rd., M-10Ottawa, ON, K2P2N7

Abstract

Gas turbine injectors, at realistic operating conditions, are difficult to characterize due to the very dense sprays that

result from large, well atomized fuel flows. The goal of this research is to establish scaling rules, such that thedroplet size and velocity of sprays that are too dense to measure can be determined semi-empirically from lower

operating conditions. This study employs a plain jet airblast atomizer operated at fuel flow rates up to 20g/s and air

pressures up to 15 bar at 293K. Preliminary results show that if the air-fuel-ratio and percent pressure drop are heldconstant the measured droplet size increases with increasing ambient pressure, with only minor variations in axial

droplet velocity.



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Design and Validation of a Fuel-Air Mixer for a Portable Reformer

M. L. Corn*, L. M. Chiappetta, W. H. Borst, J. T. Costello, and S. C. Emerson

United Technologies Research Center

East Hartford, CT 06108 USA

Abstract

The challenge of atomizing and fully vaporizing a low flow rate of jet fuel in a logistic fuel reformer intended forportable fuel cell applications was met through a combined experimental and modeling effort. The design con-

straints led to the selection of a commercial, off-the-shelf twin-fluid atomizer for the mixer. Unheated, unconfinedspray tests with the atomizer were conducted to acquire droplet size measurements at a 0.39 kg/h flow rate and at

air-fuel ratios of 4 and 6. CFD modeling used these data to help define inlet boundary conditions and predict the

mixing and vaporization performance of the fuel injector under heated conditions in a confined cylindrical geome-

try. Heated tests verified that the spray was fully vaporized before the exit plane of the cylindrical mixer. All of theconstraints for the mixer were met with the atomizer except for the gas pressure drop, which was 20 to 40 times

higher than the design target.




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Modeling Low-Pressure Injections in Diesel HCCI Engines

Yong Sun*and Rolf D. Reitz

Engine Research Center, Department of Mechanical Engineering

University of Wisconsin-MadisonMadison, WI 53706-1609 USA

Abstract

Homogeneous Charge Compression Ignition (HCCI) combustion is being considered as an alternative to conven-tional engine combustion systems due to its high efficiency and low engine-out emissions. To prepare a homogene-

ous mixture for diesel HCCI combustion, two types of low pressure (5MPa~20MPa) injectors were considered: a

swirl injector and a multi-hole injector. A modified version of the KIVA-3V R2 code, was used to simulate the two

types of injections. The Kelvin-Helmholtz and Rayleigh-Taylor (KH-RT) hybrid breakup model, which is often usedto simulate droplet breakup processes of high-pressure (50MPa~300MPa) diesel injections, was recalibrated and

extended for low-pressure, multi-hole injection applications. Two techniques were used to improve the prediction of

spray behavior: use of an independent collision mesh with random rotation, and coupling the gas and liquid phasesusing polar interpolation. The numerical models were validated by comparing simulation results with experiments

under different conditions. The simulation results show that the spray structure of the swirl nozzle injection is sensi-

tive to the intake flow field and in-cylinder gas density, while the spray structure of a multi-hole nozzle injection isless influenced by the in-cylinder flow and gas density. The simulation results also show that swirl injectors are

more suitable for low ambient pressure (0.3MPa), the hollow-cone

spray collapses into a solid-cone spray. Multi-hole injectors are more suitable for high ambient pressure conditionsbecause at low pressures, the spray penetration is too long, which can cause spray-wall impingement.



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Spray Velocity and Drop Size Measurements

in Vacuum Conditions

Renaud Lecourt*and Philippe Barricau

ONERA, Mauzac, France, 31410

andJohan Steelant

ESA-ESTEC, Noordwijk 2200 AG, Netherlands

Abstract

Injection or expelling of liquid propellants in vacuum conditions occurs in rocket engine starts or ventings in orbit.

This involves flashing atomisation which then rules engine ignition or droplet dispersion around the spacecraft. A

literature survey was undertaken on flashing atomisation and on related detailed experiments. Then, to complement

the literature database, experiments were carried out to obtain spray drop velocity & size measurements when high-

pressure fluid is injected into near vacuum conditions typically observed downstream from rocket engine injectorsand venting devices of upper-stages or spacecraft. The results show how flash atomisation in vacuum conditions

increases the droplet velocities and decreases their size, compared with non-flashing conditions. From these results,

several correlations were established for the different injectors according to injection velocity and superheat level.


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Towards an Efficient Nonlinear Atomization Model for Thin Liquid Films

C. Mehring*

Division of EngineeringColorado School of Mines

Golden, CO 80401, USA

AbstractReviewed is a previously developed nonlinear thin-film lubrication model aimed at the prediction of spray forma-

tion from thin films such as those found in gas-turbine engines (e.g., prefilming air-blast atomizers), heavy fuel-oil

burners (e.g., rotary-cup atomizers) and in the paint industry (e.g., flat-fan atomizers). Various implementations ofthe model focusing on different physical aspects, i.e., effect of film geometry, surface tension, liquid viscosity, cou-

pling with surrounding gas-phase flow, and influence of long-range intermolecular forces during film rupture, are

reviewed together with a validation of the predicted nonlinear wave-propagation characteristics for inviscid films

using a two-dimensional discrete vortex method. An extension and generalization of the current nonlinear film

model towards a film atomization model suitable for implementation into a general- purpose CFD solver is outlined.


Poster - 3


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Impact Dynamics and Cooling of Water Droplets Impinging on Hydrophobic and

Hydrophilic Surfaces

A. Sanjeev, O. Huzzayin, K. P. Gatne, R. M. Manglik, and M. A. Jog*

Department of Mechanical, Industrial, and Nuclear Engineering

598 Rhodes Hall, P. O. Box 210072University of Cincinnati, Cincinnati, OH 45221

Abstract

Heat transfer to a hot water droplet impinging on a cold substrate is numerically and experimentally investigated.

The droplet impact on both the hydrophobic (Teflon) and the hydrophilic (glass) surfaces are considered for a drop

Weber number of 20. The drop deformation, spreading and recoil dynamics are captured using a high-speed digital

video camera at 4000 frames per second. A finite volume method is used to numerically model the transient drop

behavior and heat transfer. The liquid-air interface is tracked by the volume-of-fluid (VOF) method. The high-speedvisualization and computations reveal that surface wettability significantly affects the spreading-recoil behavior and

droplet cooling. On the hydrophobic substrate, the water drop spreads and then recoils sharply so as to form a

vertical column, which breaks up and ejects secondary droplets. The hydrophilic surface facilitates larger drop

spread followed by weak recoil, which leads to a higher rate of heat transfer from a hydrophilic surface compared toa hydrophobic surface.

* Corresponding author

Poster - 5


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Film Separation Criterion with Experiemental Validation for Dynamic Shear-

driven Thin Liquid Films in Separated Gas Flows

M.A. Friedrich, H. Lan, J.A. Drallmeier, and B.F. Armaly

Department of Mechanical and Aerospace Engineering

University of Missouri-RollaRolla, MO 65409-0050 USA

The onset of separation of sheardriven liquid films from a solid surface due to a sudden expansion in

geometry is studied. The thin (~300 m), horizontal film is driven by an adjacent gas flow and interacts

with the separated gas flow at a sharp 60 expanding corner on the lower wall. The objective is thedevelopment of a comprehensive separation criterion for predicting whether the film will separate from the

corner and break up into droplets or negotiate the corner and stay attached. Quantitative estimates of the

film thickness and velocity just before separation is made using a simple two-dimensional film propagation

model. Using these estimates, a force balance is then performed to predict the separation or attachment of

the liquid film at the corner. Forces include momentum flux, surface tension forces and gravitational forcesacting on the film over the breakup length. Observations using high speed imaging as well as quantitative

measures of liquid mass attached to the wall after the corner are used to demonstrate the effectiveness of

the criterion to predict the onset of separation.

Poster - 6


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Risi, A. D. Wed., 3A / 2

Rizoiu, I. Thu., 1B / 2

Rohani, M. Fri., 2A / 1

Rosenzweig, L.

Thu., 4B / 4Sallam, K. Thu., 4A / 1

Sanjeev, A. Poster 5

Sanjeev, A. Thu., 4B / 1

Sarchami, A. Fri., 2B / 2

Schick, R. J. Thu., 2A / 1

Schick, R. J. Thu., 2A / 4

Schick, R. J. Thu., 3B / 1

Schock, H. Poster 8

Sedarsky, D. L. Wed., 4A / 1

Sedarsky, D. L. Wed., 4A / 3

Selle, L

Wed., 1B / 1Shams, E. Thu., 2B / 2

Sharma, N. Thu., 4A / 2

Shedd, T. Fri., 3B / 1

Shrimpton, J. S. Wed., 3A / 1

Sirignano, W. A. Fri., 1B / 1

Sivathanu, Y. Thu., 4A / 2

Sivathanu, Y. Thu., 4A / 4

Sivathanu, Y. Wed., 2B /

Smith, C. E. Thu., 1A / 2

Sojka, P. Thu., 4A / 2

Spiekermann, P Wed., 1A / 2

Stamper, J.

Fri., 2C / 2Steelant, J. Fri., 4B / 1

Steinhaus, B Wed., 1A / 3

Steinhaus, B. Fri., 3B / 1

Stringer, V. Fri., 3C / 3

Subramaniam, S. Wed., 4B / 2

Sun, Y. Fri., 3C / 1

Talley, D. G. Wed., 2A / 3

Tanner, G. Fri., 1C / 2

Thibault, J-P. Wed., 2A / 4

Ting, F-C. Wed., 4B / 3

Tiwari, A. Fri., 1B / 3

Trujillo, M. F.

Poster 3

Trujillo, M. F. Poster 4

Varanasi, P. Thu., 4A / 2

Vieille, B. Wed., 2A / 4

Vu, H. Thu., 2A / 2

Wang, J. Fri., 1A / 2

Wang, J. Wed., 2B /

Wang, K-T. Wed., 3B / 2

Wang, Y. Fri., 1A / 2

Wulteputte L. Fri., 4B / 2

Wulteputte, L. Thu., 3A / 3

Xu, Y.

Fri., 1A / 3Yang, S-L. Wed., 4B / 3

Yoon, S. S. Thu., 4B / 2

Zeles-Hahn, M. Thu., 1B / 1

Zeles-Hahn, M. Thu., 1B / 3

Zeng, Y. Thu., 3B / 2

Zhang, Y. Poster 8


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Documents

Ilass Book of Abstracts 2007