Summary of Low-Speed Airfoil Data - Aerospace Engineering

363 Pages·2012·8.15 MB·English

Summary of Low-Speed Airfoil Data
Gregory A. Williamson, Bryan D. McGranahan, Benjamin A. Broughton, Robert W. Deters,
John B. Brandt, and Michael S. Selig
Volume 5
Summary of Low-Speed Airfoil Data
Volume 5
Gregory A. Williamson
Bryan D. McGranahan
Benjamin A. Broughton
Robert W. Deters
John B. Brandt
Michael S. Selig
Department of Aerospace Engineering
University of Illinois at Urbana-Champaign
Summary of Low-Speed Airfoil Data
Volume 5
Copyright(cid:13)c 2012by
GregoryA.Williamson,BryanD.McGranahan,BenjaminA.Broughton,RobertW.Deters,
JohnB.Brandt,andMichaelS.Selig
Allrightsreserved.
Onthecover: Supra134-in(3.4m)spansailplanedesignbyProf.MarkDrela(MIT)
with his AG40d airfoil used at the root section and tested in this volume.
Williamson,GregoryAlan
SummaryofLow-SpeedAirfoilData–Volume5/byGregoryA.Williamson,BryanD.McGranahan,
BenjaminA.Broughton,RobertW.Deters,JohnB.Brandt,andMichaelS.Selig.
Includesbibliographicalreferences.
1.Aerofoils(Airfoils). 2.Aerodynamics. 3.Airplanes—Models.
I.ModelAviation. II.Title
SummaryofLow-SpeedAirfoilData
Contents
PrefaceandAcknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
ListofFigures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
ListofTables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii
Chapter1 TheAirfoilsTested . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Chapter2 ExperimentalMethods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 ExperimentalTechniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 DataValidation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Chapter3 SummaryofAirfoilData . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.1 GeneralCommentsforWindTunnelTestsandResults . . . . . . . . . . . . . . . . . . . . 13
3.2 DiscussionofSelectedAirfoilModelsandTestConditions . . . . . . . . . . . . . . . . . . 16
Chapter4 AirfoilProfilesandPerformancePlots . . . . . . . . . . . . . . . . . . . . . . . . . . 21
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295
AppendixA TabulatedAirfoilCoordinates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297
AppendixB TabulatedDragPolarData . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319
ii SummaryofLow-SpeedAirfoilData
Preface and Acknowledgments
Summary of Low-Speed Airfoil Data – Volume 5 represents the fifth installment in a series of books doc-
umenting the ongoing work of the University of Illinois at Urbana-Champaign Low-Speed Airfoil Tests
(UIUCLSATs). Theproject’spurposeremainsunchangedsincetheoriginalworkwasperformedanddoc-
umented in Airfoils at Low Speeds (SoarTech 8)1 by Michael Selig, John Donovan, and David Fraser at
Princeton—todevelopandtestairfoilsforlow-speedaircraft,inparticular,RCmodelairplanes. However,
theapplicationoftheresultshavespreadbeyondtherealmofRCmodelairplanestounmannedaerialvehi-
cles(UAVs),low-speedpropellers,windturbines,andmoresincethetimeSoarTech8waspublished. This
currentprojectisanexampleofthebroadeningscopeoftheLSATsprogramwiththeexaminationofflaps
onsailplaneairfoils,variousleadingedgesonaflatplatemodel,andothers.
The UIUC LSATs team during the acquisition of the data presented in Volume 5 consisted of Michael
Selig (Assoc. Prof.) as project advisor, Bryan McGranahan (M.S.) as project coordinator from 2002 to
2003,JohnBrandt(M.S.)asprojectcoordinatorfrom2003to2005,andRobertDeters(Ph.D.candidate)as
project coordinator from 2005 to 2010. Testing was conducted during many test campaigns from 2002 to
2010.
It is our intention for Summary of Low-Speed Airfoil Data – Volume 5 to follow closely the format of
thepreviousvolumesmakingthecurrentinstallmenteasytonavigateforthosefamiliarwiththeseries. As
before,Chapter1discussesthescopeofthecurrenttestsandbrieflydescribestheairfoilsandconfigurations
tested. Chapter 2 gives an overview of the testing facility, LSATs measurement hardware, and flow qual-
ity of the UIUC low-speed subsonic wind tunnel. Additionally, Chapter 2 provides a comparison between
UIUC LSATs data and data obtained by NASA Langley in the Low-Turbulence Pressure Tunnel (LTPT).
Chapter 3 discusses the airfoils tested, and Chapter 4 contains the corresponding performance plots, in-
cluding pitching-moment data. Appendices A and B list tabulated airfoil coordinates and drag polar data
respectively.
Our research into the aerodynamics of airfoils at low Reynolds number would not have been possible
without the generous contributions of many individuals to which are indebted. We thank all of our past
contributors who are mentioned in our prior volumes. The foundation provided by those supporters paved
the way to producing the results reported here. For the time period that spans this volume, the generous
supporters who provided funding include Neal Brutsche, Pete Carr, Les Garber, John Hunter, Dave Jones,
Mr. Kraus, Ing. Jaroslav Lneˇnicˇka, Eric Loos, Larry McNay, Gilbert Morris, Pete Peterson, John Rimmer,
JerryRobertson,PhilRockwell,AllanScidmore,MartinSimons,ArthurSlagle,HerkStokely,Dr.Wilfried
Stoll,CraigSutter,andJoseTellez.
Also greatly appreciated is the time and effort spent by many people constructing the wind tunnel
tunnel models presented in this volume. These individuals include Thomas Akers (S9000), Mark Drela
(hardware fabrication and installation, filling, shaping, and polishing of the AG12, AG16, AG35, AG40d,
andAG455ct)andhisteamLaszloHorvath(foamcorecuttingforall),RobGlover(AG12,AG16coreprep
andbagging),JohnJenks(AG24,AG35coreprepandbagging),OlegGolovidov(AG455,AG40coreprep
iv SummaryofLow-SpeedAirfoilData
and bagging), Ralph Cooney (MA409), Camille Goudeseune and Michel Goudeseune (Flat Plate), Chris
Greaves (CAL2263m), Tim Lampe (CAL1215j, S8064), Mark Nankivil (NACA 43012A), Jim Thomas
(CAL4014l),andYvanTinel(E387,S1223).
We are also indebted to our collaborators in the UIUC Aerodynamics Research Laboratory including
Michael Bragg, Greg Elliott, and Andy Broeren (now at NASA Glenn). We also want to thank former
studentswhoparticipatedintakingdataforthisvolume: TomoSato,KianTehrani,andPaulGush.
And finally, special thanks go to the sponsors of our research in the UIUC Applied Aerodynamics
Group. This ongoing research for our sponsors has been instrumental in maintaining the continuity of our
low Reynolds number test program and overall laboratory activities and infrastructure. These sponsors
include Ford Motorsports, NASA Glenn, AeroVironment, DOE National Renewable Energy Laboratory,
WindLite,NewmanHaasRacingNavalResearchLaboratory,SiemensCanada,JaguarRacing,OracleRac-
ing/Farr Yacht Design, Continuum Dynamics, Luna Rossa, Arcturus UAV, Spin Master, ICON Aircraft,
FlexSys,NorthernPowerSystems,GEEnergy,and3M.
List of Figures
1.1 AirfoilstestedfromFall2002throughSummer2010. . . . . . . . . . . . . . . . . . . . . . . 1
2.1 UIUClow-speedsubsonicwindtunnel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2 ExperimentalSetup(Plexiglas(cid:13)R splitterplatesandtraverseenclosureboxnotshownforclarity). 6
2.3 Turbulence intensity taken at tunnel center with the LSATs test apparatus installed with no
model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.4 ComparisonbetweenUIUCandLTPTE387dragcoefficientdataforRe =60,000,100,000,
200,000,300,000,and460,000. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.5 Comparison between UIUC and LTPT E387 lift coefficient data for Re = 60,000, 100,000,
200,000,300,000,and460,000. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.1 SchematicoftheGurneyflapandboundary-layertripconfigurationsusedontheS1223.. . . . 16
3.2 SchematicoftheAG35-rshowingchordlineandwingmounts(drawingbyDrela15). . . . . . 17
3.3 AG455ct-02r airfoil with four flap positions −4, −2, 0, and 2 deg, shown with the vertical
scaleexaggerated3X(drawingbyDrela15). . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3.4 Baselineflatplateandvariousleading-edgeconfigurationsdrawntoscale(butnotfullspan). . 18
4.1 ComparisonbetweenthetrueandactualAG12. . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.2 InviscidvelocitydistributionsfortheAG12. . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.3 DragpolarfortheAG12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4.4 LiftandmomentcharacteristicsfortheAG12. . . . . . . . . . . . . . . . . . . . . . . . . . . 32
4.5 ComparisonbetweenthetrueandactualAG16. . . . . . . . . . . . . . . . . . . . . . . . . . 36
4.6 InviscidvelocitydistributionsfortheAG16. . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
4.7 DragpolarfortheAG16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4.8 LiftandmomentcharacteristicsfortheAG16. . . . . . . . . . . . . . . . . . . . . . . . . . . 38
4.9 ComparisonbetweenthetrueandactualAG24. . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.10 InviscidvelocitydistributionsfortheAG24. . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.11 DragpolarfortheAG24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43