NASA NACA-TN-4185-1958 Wind-tunnel investigation of effect of sweep on rolling derivatives at angles of attack up to 13 degrees and at high subsonic Mach numbers including a semiemvati.pdf

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-,-,-