1、NATIONAL ADVISORY COMMITTEEP .FOR AERONAUTICSTECH3dC.AL.NOTENo. 1277TWO-DIMENSIONAL WIND-TUNNEL INVESTIGATION OF THENACA 64112 AIRFOIL EQUIPPED WITH TWO TYPESOF LEADING-EDGE FLAPBy Fel.icienF. Fullmer, Jr.Langley Memorial Aeronautical LaboratoryLangley Field,Va.WashingtonMay 1947Provided by IHSNot f
2、or ResaleNo reproduction or networking permitted without license from IHS-,-,-. *erIWITONAL AIWISO1+YCOMU!ITEE,.a71FOR AERONAUTICSTFLHNICAL ITOTENC).12TWO-DIMEPSXONALWIND-TUNNEL INVESTICUMTON CE”TEENACA 641-OK!AIRFOIL EQ)?ED WTIE IWOTYPESOF LIMDING221X2EFIATBy Felicien F. FuUmer, Jr.fmMMR-YAn invest
3、igationwas made tn the Langley two-dnsional” iO-turlnilenceressuzzetumel to determine the characristics of leading-edge flaps used as Mfih-lif% evices.t The invmtigatipn, conducted ata eynolds nwnber of 6.0 x 20, included tests of two 10-psrcent-chor:NkCATNI?o. X277square inch end aSUSd%foot whichau
4、d a Mach numberTest5-c Press= of approxhately 70 pounds percorrespond to a Reynolds nuniberof 6.0 x 106of 0.11.Methods and -1 co1V8CtiOIMThe lift characteristicsof airfoils teste in the Langleytwo-dimensional low-turbtiemcepreseure tunnel are obtained by inte-grating, over a finite total lift. - -Co
5、rrections for the wind-tunnel-wellthe following equations, where the primedquantitiesmeasured in the tunnel:Uo = 1.olol. .CT = o.978czfeffects were made bysymbols represent the%pk .= *993c%/4rA cormciion has also been applted to the data esented hereinfor the blocking effect at angles of attack nesr
6、 maximum Lift.This correction for the blocking effect reduces the maximum liftcoefficient masured in the tunnel by approximately 1.5 percent.Previous comparisons .ofthe lift coefficients bbtained from themeasurement of the pressure reaction on the floor and ceilhg ofthe”tunnel.were”inclose agreen!nt
7、with those obtained from airfoilpressure distributions-andforce teats. The probable error inindividualtest points as determined from check tests, considera-tion of the sensitivity,of the measuring instruments, and thedeparture of points from the faired curves is estimated to bewithin the following l
8、imits:Over the iinea,r,C1 . . . . .ck/4 “ “” a71%. . . . .portion of the lift curve:. . . . . . . . . . . . a71 . . :0.005. 0 . . . . . . . . . *6*(X)2 0.10a71 *,. . * . . .Near maximum lift coefficient:. *0.020%,;:.=:,:. * 0.010#10,.% *V*=*.*.* *9*o*0Provided by IHSNot for ResaleNo reproduction or
9、networking permitted without license from IHS-,-,-6 NAC!ATN No. 1.2RESULTS AND DX3CWSSIONThe lift characteristicsobtained from tests of the variousairfoil flap configurationsare presented in figures 5 to 7.The pitching+nomentcharacteristicsof the plain airfoil, of theairfoil-trailing-edgeflap model,
10、 and ofthe optimum airfoil-leading-edge-flaparrangementstested are presented In figure 8.The effect of leading-+dgerouness on the lift characteristicsofboth the plain airfoil and the airfoil with the trailing-edge flapis shown in figure 9; similar data for the best airPoil-leading-ede-flap arrangeme
11、ntstested are presented in figure 10. Thevariation of the incrementsof maximum section lift coefficienth 2- and of section angle of attack for maximvm section lift.coefficient with leading-edgeflap deflection is presentedin figure 1.1.Lift CharacteristicsThe data presented in figures 5 to 7 show tha
12、t the bestarrangements of leading+dge flaps of the type tested increaaedthe maximum section lift coefficient end also the section angle ofattack at which the maximum lift coefficient occurs. The n hoever,-from figures 5 and 6 that a leading-edgeflap of this type is somewhat sensitiveto changes in fl
13、ap deflec-tion for the reasons given inthe previous general discussion ofboth types of leadindge flaps. A comparison of the datapresented in figures 5 and 6 and the increments obtained indicatesthat the presence of the split trailing-edge flap altered the flowcharacteristicsin such a mmner as to inc
14、rease the effectivenessof the leading-edge flap at deflections as low as 103. Thecross plot (fig. 10) shows that the presence of the tra?lidgeflap, as previouslymentioned, had a pronounced effect on thedeflection at which the best Himum lift coefficient incrementwas obtained. For example, the optimu
15、m deflection for the leading-edge flap when used clone was 120, but when used in conjunctionwith the trailing-edge flap, the optimum deflectionwas 112.UppeHurface flap.- An examination of the section liftcharacteristicspreeenved in figrcre7 shows that this uppesurface leadindge flap, when used in co
16、njunctionwith the plainairfoil, produced a maximum section lift coefllcient of 1.85 atan angle of attack of 18.3. These values correspondedto anncreffient%- = 0.43 and an increment = 4.0 above thevaluea obtainablewith the plain airfoil. The same figure showethat the use of this leadi+dge flap in con
17、junctionwith theairfoil antisplit trailing-edge flap produced a maximum liftcoefficient of 2.98 at an angle of attack of 16.2, which corre-sponded to Increments Act = 0.81 and ho = 6.9 above thatmaxobtained for the airfoil and split trailing-edge flap arrangement.The data presented in figure show th
18、at at low angles of attackthis flap also produces decrements in the section lift coefficients.The rapid decrease in the magnitude of this decremmt in liftcoefficient shows, however, that the spoiler action is somewhatless severe for this flap than it is for the lower-surfaceleading+.dge type of flap
19、.The results given in figure 11 indicate that the incrementsh 1- and Am. were considerably greater for the upper-surfaceleadindge flap. This canbe attributed to the slightly greaterproflectedarea and smooth contour of the uppev-surface leadindgeflap.“.IProvided by IHSNot for ResaleNo reproduction or
20、 networking permitted without license from IHS-,-,-Pttching40ment Characteristics9:A comparison of the pitchinoment data obtained for theplafn alrfofl and the airfoil trailtng-edge flap arrangement withdata obtained for the seam arrangements equipped with the lower-or upper-surface leading-edge flap
21、s (fig. 8) shows that theaddition of either flap caused the moment coefficients to increasenegatively with increasing lift coefficients until the angle ofattack was approximately high enough for the flap to cease actingas a spoiler. As the lift coefficient is increased beyond thispoint, the moment c
22、oefficients increase positively in a mannercorresponding to a forward position of aerodynamic center withrespect to the qusrter+hord poirrtof the original model. Sucha forward position of the aerodynamic center is consistentwiththe fact that area has been added shead of the leading edge ofthe plain
23、airfoil. The forward shift in the position of theaerodpamic center was slightly greater for the uppeurfaceflap installation than for the lower-surface flap installation.The results show that increments In pttching+oment coefficientwhich were obtained from the addition of either of the leading-edge f
24、laps areresulting fromflapa71relatively small in comparison with the incrementdeflection of the conventional split trailing-edgeEffects of Leadi.na71 10.0 3.871 30.01.o 4.620 3.5.0 -4:62020.0 5.173 20.0 +.i7325.0 5.576 25.0 +. 57630.0 5.844 30.0 -5 a71eb435*O 5.978 35.0 -5.97840.0 5.981 40.0 -5.9814
25、5.0 5.79$ 45.0 -5,798!jO.o 5.480 .o -5.48055.0 5.056 55e(l “ -5.05660.0 4.548 60.0 -4. P4867.0: .;: 65.0 -3.97470.0 70.0 -3.35075,0 2:695 75.080,0 -. 6952.029 80.0 -2.02985.0 1.382 , 87.0 -1.38290,0 .786 go.o -.78697.0.288 95.0 _,cJ38100 0 10CJ oL. E. radtue: 1.040IiATZONALADTIXqORYCOMMITTEE FOR KER
26、OHAUlVC!SProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.* . I. .,. . * .(a) Z%ree-quarterr earviewo fmodels howingt heinstallationoftheleading- andtrailing-edge flaps. Figure l.- Photographs of the NACA 641-012 airfoil section and the O.10c lower-s
27、urfaceleading-edge flap alone and in combination with the 0.20c trailing-edge split flap.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.-., ., ,. “(b)”Three-quarter frontview ofthemodel showing thecontourofthelower-surface leading-edgeflap.Figure 1
28、.- Concluded.Ig!.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Stat:(-.- .I2.25 Station 12.25 Station 20.00IStation 11.47II . ;Airfoil hord line -l?lapretpactecl-.- x- If /I.0078c /r fL-E.801 NATI04AJ. ADVISORYCOMMITTEE F(M AERONAUTICSFigure 2.- Sk
29、etch showing the lower-surface leading-edge flap arrangement on the .MNACA 641-012 airfoil section.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-,. . .-.I.- .(a) Sideview ofmodel showtig installationofupper-surface leadbg-edgeflapand lower-surface
30、trailing-edgeflap.Figure %- Photographs oftheNACA 64,-012 airfoilsectionand theO.1OC upper-surfaceleading-edgeflapfioneand incombtion withtheO.Z)Ctmiling-edge spiltflap.ORYSeotlon angle of attack, a.$ degFigure 9.- The effeetof leadlng-edge roughness on the section liftcharacteristics of the NACA 64
31、1-012 airfoil with and without atraillng-edge splt flap. R = 6.0 X 106.F*.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I WI I I I I-. L B -H-l O“li” -: Laadiog.dg. flab!-EFBR-h$i?r-. -(3KO - Mading-edge flap-.Ou? 60 L9ading- and trau.-1,2 I , , I
32、-16 4 0 8 16 *322VMM6omdition.%otlon mwle of attaok, %, deg Suitian We of nttank, ao. -8 (a) IOweranrfnae leading-adge flap. (b UPPor-mwfaM lmdlqq+ flaP.b 1o.- Tba effeat of badindge rmglmaom cm tb saatlonMft olmwterlationof10mdi?lg-* end traillng-c.dgesplit fza . , . ,* M6kOIZ tiou equipped .iwtkur
33、faoeamditim&OOulF&u&.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Fig. 11 ?NACATN No. 1277(3 bwer.sfaoe leading-edge flapE Lower-surface leading-edge-flapwith trailing-edgeflapG Upper-surfaceleading-edgeflapA Upper-surface leadimg-edgeflapwith tea
34、lling.edgeflap8,A4 ? . - w?-k.8 A.4 a o% P7 NAtlONAL ADVISORYCOMMITTEE FOR AERONAUTICS-. 480 100 120140 160Leading-edgeflap deflection, 5fL.E.S degFigure 11.- Varlation of the increment of maximum section liftcoefficientand the incrament or section angle of attack formaximum section llft coefficient with leading-edge flapdeflection. NACA 641-012 alrfotl aectlon with leading- andtrallng-edge split flaps. R = 6.0 x 106.7Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
