REG NACA-ACR-L4F23-1944 Wind-tunnel investigation of control-surface characteristics XIX - a double flap with an overhang and an internal aerodynamic balance.pdf

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1、, ,(.1 “, i,Ij? ,/. /.NATIONAL ADVISORY COMMITTEE FOR AERONAUilCSORIGINALLYKSUEDJune14 asAdvanceConfidentialReportLkFZ?3WummmEL GATION CIFCONIR3L-SORFAC31IGSXIX- ADOUBIiEFIAPWZI!HAN(mRHM?G ANDAN ImERmL AEROI)YNAMICBALANCE RolmrtB. Lidde31LengleyMmorial AeronauticalIxmatcry1 LangleyField,Va.FOE?REFER

2、ENCENOT TOBE TAKEiiFROM THISROOMNACA WARTIME REPORTS arereprintsofpapersoriginallyissuedtoproviderapiddistributionofadvanceresearchresultstoanauthorizedgrouprequiringthemforthewar effort.Theywerepre-viouslyheldunderasecuritystatusbutarenowunclassified.Some ofthesereportswerenottech-nicallyedited.All

3、havebeenreproducedwithoutchangeinordertoexpeditegakal distribution.sJ- 215Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3 1176013649638.NATIONAL ADVISJ3RYCOMMITTEEADVANCE CONFIDENTIALFOR AERONAUTICSREPOI?I!WTND-TTWWIL INVESTI2ATION OF 50NTROL-SURFA

4、CE CHARACTERISTIC5SXIx - A DOUBLE FLAP WTTH AN OVERHANG ANDAN INTERNAL AEROD-YN.W1C BALANCEBy Robert B. LiddellWind-tunnel tests have been made in two-dimensionalflow to investigate the aerodyzmnic characteristics ofa double flap with an internal wd an overhang balance.Three sizes of each te of bala

5、nce were tested withthree relative rates of deflection of the two flaps.An ?ACA66-C09 airfoil having a O.SO-airfoil-chordstraight-contour forward flap and.a .20-airfoil-chordstraight-contour rearward flap was used.The test results indicated that a balanced doubleflap produced the same lift 8s a sing

6、le plain flap ofthe same chord and also produced highly balanced hingemoments. High lifts and.low hine ?omentswere obtainedwith a double-flap arrangement if either an overhang oran internal balance having a chord 50 percent of theflap chord was incorporated on the forward flap. Theoverhang-balance f

7、lap showed a lower value of the hine-rroment.gradient due to flap deflection tb-anthe intern-ally balanced flap.INTRODUCTIONPrevious work (reference 1) has shovm that greaterlifts with lighter control forces could be obtained bythe use of plain-flap small-chord control surfacesdeflected to a large a

8、ngle than by large-chord controlsurfaces with a smaller deflection range. The resultsof reference 1 also showed that two small-chord flapsdeflected simultaneously in the same direction 10Uldbe aProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.-. .- d

9、 L- .-a.2combination that would give even better lift and hinge-monent characteristics. Some method of incor?oratin) deflection with respect to forwardflap, degreerear-.mrd-flap deflection with resect to airfoil,d.eErees(see fig, j); referred-to as ltotal -flap deflectionf (Ul + . . -. .-:,- TT-:. :

10、.:y-, . . , . - +.,- ,- .7 .:- , -. .- .- .-. . -.-, -,., . . . . ., . -%- -. . . . . . .-:-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. ., -., .;. . -4(,)=$)ardflap; that is, d52/d51 equalseither 1, 2, or 3. Whe forward flap was provided withth

11、ree interchangeable ?Jlunt-nossoverhang balances andthree interchangeable internal balances havin chords 25,40, and 50 aercent of the forward-flap chord. Thearrangement; tested and pertinent mcdel dimensions areshown in figure 2.l,:; “.yJ,.:- ,-.“ -$.,. . . - . . - -,. ,.-. .-,-, ,“.”_positive angle

12、s of attack - an attitude usually criticalfor a rudder. Figure 16 indicates that the flap with aninternal balance and the flap with an overhang balancehave about the same lift at the same flap deflection andat = O? althciughtkeflapwith overhang balance showsa.just slightly greater lift. Data for the

13、 0.30c plainflap of reference 5 are also presented in fiure 16 and “the similarity of the lift characteristics and those ofthe 0.30c doubls flap should W noted,IKn,geMomentThe hinge-mment coefficients of the arrangementsof balanced double flap tested showed little change withsngle of attack in the r

14、egion of low anSle of attack(figs. 4 to 15). The curves are typical of most low-dragairfoils tested at low scale, however, in that theyrapidly become increasinly nonlinear beyond a = GOcA negative value for ch2 is indicated for al? of theaarrangements except the 0.5CC1 overhang balance withdb2 = I,

15、for which Ch2a. dalwas about zero (table I). Thefl.“10double flap are smaller than those for the flap with thelinked overhang balance.The stick hinge-moment coefficients for the balanceddouble flap with a 0.50c1 balance are shovm in fibwre 19as a function of lift coefficient at three angles ofattack

16、. The characteristics of the linked-balance flap(reference 5), a 0,35c flap having conventional overhangbalance (reference 6), and a 0.20c double plain flap(;ce 1 are also included in figure 19 for com-The control stick was assumed to be limited tohowever,a relatively small force should be required

17、to return tine .control surface to neutral.6. A double-flap arrangement incorporateing anaerodynamic balance is a very promising arrangement.Inasmuch as this double flap is merely a large leadingtab, its incorporation on the tail Of an airplane shouldnot present any particularly difficult problem. T

18、here,. “.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-14NATIONAL ADVISORYCOMWITT!EEFOR AERONAUTICSCONTTDENTIALProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-, .!CONFIDENTIAL I. .c1*zoa71.Provided

19、by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.NACA ACR No. L4F23 Fig. 2adi23f2fP;bd pnCONFIDENTIAL) Intwnu/ha/umes. NATIOtJAL AIMSOWCOMMITTEE FOR AERONAUTICS.Fjgure 3 .- Arrangemetits of Lwhmeddwbk-flopmod.d teded. NACA 66-00? oiPfi# hawinga“0.30C. . . . -

20、y-. .=. . . . ,.double flop.uRIC, !Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA ACR No. L4F23 Fig. 3.“Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA ACR No., L4F23 CONFIDENTIAL Fig. 4.aP

21、rovided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.NACA ACR NO. L4F23 $ “Q$%Wm Fig. 4b /.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-/NACA ACR No. L4F23 CONFIDENTIAL Fig. 5a.Provided by IHSNot for Re

22、saleNo reproduction or networking permitted without license from IHS-,-,-NACA ACR No. L4F23 cWG#wQJ!wD Fig.I.5b. ,.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.NACA ACR No. L4F23 Fig. 6a. .,Provided by IHSNot for ResaleNo reproduction or networki

23、ng permitted without license from IHS-,-,-NACA ACR No. L4F23 Fig. “6b.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.NACA ACR No. L4F23 Fig. 7a.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-/NACA ACR No. L4F23 Fig. ?bProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-/,NACA” ACR No. L4F23a71/Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-