1、NATIONALADVISORYCOMMITTEEFORAERONAUTICSTECHNICAL NOTE 4185WIND-TUNNELINVESTIGATIONOF EFFECT OF SWEEPONROLLINGDERIVATIVESAT ANGLESOF ATTACK UP TO 13 ANDAT GHSUBSONICMACHNUMBERS, INCLUDINGA SEM3,EMPIRZCALMETHODOF ESTIMATINGTHE ROLLINGDERIVATIVESBy JamesW. WigginsLangleyAeronauticalLaboratoryLangleyFie
2、ld, Va.WashingtonJanuary1958s3.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TECHLIBRARYKAFB,NMT.,-.P.,NATIONALADVISORYCOMMITIEETECHNICALNoTEI!llllllllllllill;ll!FORAERONAUTICSUClwhereasa stableconditionisindicatedonlyattheextremeratesofroll.Theres
3、ultspresentedinfigureU showthat,ofthewingsinvestigated,tl.d.splanformshowedunfavorabledamping-in-rollcharacteristics(indicatedby C overthelargest. testrangesofMachnumberandangleofattack.thatis,zeroorslightlynegativevaluesareobtainedattheloweranglesofattackandpositivevalues. areobtainedatthehighertes
4、tanglesofattack.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-8“Infigure13, thevariationsented.Negativevaluesof pof CyP withangle(lateralforcedueindicatedatthehighertestanglesofattackandatNACATN4185ofattackispre-torolling)aremostMachnumbersforallco
5、nfigurationstested.A discussionandpossibleexplanationofthebehaviorof Cnp and Cy throughthetestangle-of-attackandMachPnumberremgeandamethodforestimatingthesederivativesarepresentedinthefollowingsection.EstimationsofRollingDerivativesRollinRmomentduetorolling.-A comparisonoftheexperimentalhowever,thee
6、xperi-mentalandpredictedvaluesshowsimilartrends.Yawinamomentduetorollinz.-Inreferences14and15,methmlserepresented”orthepredictionof Cnp throughanusingcorrespondingexperimentaldragdata.Thehasbeenshowntopredictp throughthetestangle-of-attackrangemethodinreference14angle-of-attackrange .Provided by IHS
7、Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-2T NACA.with.*enceTN4185 9considerablybetterresultsthanthemethoddescribedinrefer-1. Thisresultisprobabwduetothefactthatthemethodofref-erence15predicts%p yetirapolatingfromthepotential-flowtheorybyuseofexperimentaldrag
8、dataandanempiricallydete?hinedfactorthatisproportionaltoadrsg-centermomentarm;whereastheprocedureofreference14predictsCn byusingtheexperimentaldragdatatoPproportion%p relativetotwolmownconditions.Briefly,themethodofreference14consistsofproportioningp relativetotheconditionofpotentialflowwheretheresu
9、ltantforceisnormaltotherelativewindandtotheconditionforwhichtheresultantforceisnormaltothewingchord.Anequationispresentedtheretiforevaluat Cnp fortriangdsrwings.However,forotherwingplanforms,thisequationmustbenmdifiedasfollows:thepotential-flowvalueof p fortriangularplanforms(ref.16) mustbereplacedb
10、ythevalueforwingsoftaperratiosotherthanO,andanadditionalterm,showninreference15forlow-aspect-ratiowhgs tobearesultofwing-tipsuction,mustbecon-sidered.Withtheseconsiderationsapplied,thefollowingeqmtioncanbewritten:a71(C%=-CZptsna-K-CZp tanm- )()b% + Cnp (1)CL tip suctionwherethepotential-flowvaluesof
11、 p/ canbedeterminedfromref-erence17aneitherexperimentalorchowever,thisresultisnotsurprisinginasmuchastheexperimentalvaluesof Cyp fortheunsweptwing(which=e dueprimarilytotipsuction)presentedinfigure17indicatethat,withinthetestrangesofMachnumberandangleofattack,thetip-suctioncontributioncanbeneglected
12、.ThedataforaMachnumberof0.15(fig.17)wereobtainedfromreference18.Theleading-edgecontributionto Cnp wouldbeexpectedtovary.considerablywithleading-edgeradii;consequently,infigure21low-speedProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-N(4CAm 4185 IL.r
13、esultssrepresentedfor12.percent-thickwings(ref.19)whoseleading-.-1 edgeradiivsryfroma verysharpone to a very bluntone. Thewingsreportedinreference19hadanaspectratioof2.61, a taperratioof1.0,and450sweepback.A comparisonofexperimentalp withcal-culatedvaluesevaluatedbyuseofequation(1)ispresentedtifigur
14、e22forthewingsofthepresentinvestigationatvariousMachnmberswherebothexperimentalandcalculatedvalusof Ctp wereused;thetip-suctioncontributionto C9 wasassumedtobeO. Theagreementiscon-sideredgoodforallwingstestedwhereeitherexperimentalorcalcu-latedClp areusedinequation(1),andtherestitspresentedinfig-ure
15、s21and22indicatethatthepresentmethodofestimatingCnp(eq.(1),withouttip-suctioneffects)isapplicableoverlsrgersngesofleading-edgeradii,wingthickness,andsubsonicMachnumbers.Lateralforceduetorolling.-Anexpressionfordeterminhg Cypforthepotential-flowcasecanbeobtainedfromreference17andwrittenas.4and,forthe
16、nonpotentialthewingchordplane,Cyp= CL A+cosA t=AA+kcosAcase,whentheresultantforceisnormaltowouldbeeqwl toO. Byconsideringthetip-suctioncontributionandbyapplyingthefactorK,theequationcanbewrittencYp (=K )+cOsA tanA +A+4COSAwherethetipcontributionto Cyp canbe() (2)p tipsuctionexpressedas()CYP %=tipsuc
17、tion AInfigure23,valuesof Cyp evaluatedbyequation(2)andvaluesdeterminedbythepotential-flowmethodofreference15arecomparedwithlow-speeddataofreference19. Intheapplicationofequa-tion(2),thecontributionofthetipwasassumedtobezero;however,. theorderofmagnitudeofthetip-suctioncontributionisindicated.Provid
18、ed by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I-2 NACATN4185inthecomparisonofthevaluesdeterminedbytheproceduresdescribedinreferences15and17.Betteragreementisindicatedwhenequation(2)ofthepresentpaperisused;however,thisagreementisnotsurprisinginasmuchasthe
19、methodsofreferences15and17donotaccountforanynonpotential-floweffectsontheleading-edgecontribution.Theresultsofthepresentinvestigationarecomparedwithvaluesevaluatedbyuseofeqyatidn(2),withouttip-suctioneffects,infigure24. Theagree-mentshownisreasonablygood,particularthenegativetrendindicatedatthehighe
20、rtestanglesofattack.CONCLUSIONSAninvestigationconductedtodeterminetheeffectsofsweepangleontherollingderivativesathighsubsonicMachnumbersandhighsnglesofattackfora seriesofsweptwingswithaspectratioof4,taperratioof0.6,andNACA6zo06airfoilsectionsindicatesthefollowingconclusions:1.Theresults showlargered
21、uctionsinthedamping-in-rollderiva-tive Czp atthehighertestanglesofattackforallwingstested.Ofthewingsinvestigated,theresultsforthe32.6osweptbackwingshowedunfavorabledsmping-in-rollclw?acteristics(indicatedby Up) overthelargestrangesofangleofattackandMachnumber.2. Wingfencesonthe45sweptbackwingatthe65
22、-percent-semispanstationareshowntoimprovethedamping-b-rollderivativeCzp atthehighertestanglesofattackrelativetotheclean-wingconfiguration.3. h general,thevariationofthedamping-in-rollderivative%patzeroangleofattackwithsweepanglewasonlyinfairagreementwiththepredictedvariationwithsweepangle,inasmuchas
23、the32.6sweptbackwingshowedmoredampinginrollintheMachnumberrangefrom0.85to0.93thananyoftheotherplsmforms.4.Thepredictedvariationof Czp atzeroangleofattackwithMachnumberwasingoodagreementwiththeexperimentaltrenduptothecriticalMachnumber.5. Contrsrytopredictionsbasedonpotential-flowtheory,theyawingmome
24、ntduetoroll- Cnp waspositivemd thelateralforceduetorollingCyp wasnegativeatthehighertestanglesofattackforall.#y-.4wingstested.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACATN4185 136. Theresultsindicatea lossinwing-tipsuctionwithinthetest-i ran
25、gesofMachnumbersndangleofattackinvestigated.7. PresentedhereinisamethodofestimatingCnp (yawingmcmentduetorolling)and Cyp (lateralforceduetorolling)throughthetestangle-of-attackrange.Thismethodisshowntobeapplicableoverlsrgerangesofleading-edgeradii,wingthickness,andsubsonicMachnumbers.LangleyAeronaut
26、icalLaboratory,NationalAdvisoryCommitteeforAeronautics,LangleyField,Vs.,MarchU, 1954.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-14 NACATN4185REFERENCES1.Wiggins,JsmesW.,ad Kuhn,RichardE.: Wind-TunnelInvestigationoftheAerodynamicCharacteristicsin
27、PitchofWing-l?uselsgeCom-binationsatHigh-S.g79.2785.37 4:3491.46 3.81lfx).oo 3.35Leading-edgeradius=0.0006z.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-:T.%NACATN4185 17L1-fti iReknivewind RollingmomentandrollingvelocityzFigurel.-Systemofaxesused
28、showingpositivedirectionofforces,moments,es, =d elotiesa71.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.Fuss81Length 49Ehl.Atarn.dish. 5 in./+tion of max. dknn 30 in.T 30” % -.,S?6”-=-+_. %3B-4-O.6-CW6Figure2.-I13,?.6-4- 0.6-006Sketch of fourWhg:
29、Arua P.W Sr/ftSpan 3.oftcm? 675in.Root ii25 in.Msan aarvoamk W 765ftASPSCtrut.% 4.0Taper ratio 6?6imidsnce oRimi oAiWi smtbn/waii8i to fueei NACA 63A08 $ 04 .08 .12 -,0804 0 . .08pbmPbm 27(b) 32.6-4-.6-006 ting.Figure8.-continued.IProvided by IHSNot for ResaleNo reproduction or networking permitted
30、without license from IHS-,-,-Unflacjtjedsymbok, cktm wingFkgged symbols, fence onQ=/08 a= /2.9.04M Ao .03 0,8500 .02 0.7UU0 .0/ o.509q o 0-.01-.02-.03-.04-./2 -Q8 -,04 (_(_ .(% .(% ./2 -./2 -.08 JJ# $ .04 .08 ./2m 2P(c) 45-4-.6-006 Wing.Figure8.- Concluded.1. . 11 IEt=Provided by IHSNot for ResaleNo
31、 reproduction or networking permitted without license from IHS-,-,-NACATN4185.27M.8500moo .0/5oocn oMB500.500 c o-.0/From b-#o+gpia pb- From+nto-w= /3u-./2 -.08 04 Opb2VFigure9.- Variationofyawingmomentwithinhightestangle-of-attackrange.04 .(28 ./2wing-tiphelixanglepb/2V “-3.6-4-.6-006wing.-Provided
32、 by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-M93 h.91 A.550.70 n500Czpo0000.I-2-.3-.4.,024A ngfeaFigure10.-.6 8 /0 12 Mof C?t)ack,a, day3.6-4- .6-ci)6 wing.Vaxiatioof ClPnotcarectedru0302468 #j2j4Angle of utfmk, Q,d.(b) 32.6-A-.(5-006 W*.with angle of att
33、ackforwingstested.Datafor aeroelasticdistortion.IIProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. a71 IIll(Unfged symbols) cleon whg.93ho -(Flagged symkk+j fence onMUnce&inties Indicated on fure8. I.9/ A.850.70a75.500“O 2 4 6 8 /0 IZA ngfe of attack, a, deg(C) 45-4-.6-006 wing.Fre 10,-000000/4(d)02468Angle of atfack,a,cg60-46-006Concluded.wing .!2Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
