1、a#,NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS ORIGINALLYISSUEDDeccnaber1945 a8AdvanceConfidentialReportLTW -DIMENSIONALWIND-TUMREL13VFSTI(XTIONOFO.20-AIllEUIIAEOKDPLAIIVAICJ!RMSOFCOFIIIOUROHM HACA 651-210 AIRFOILBy WilliamJ. Uhderwood,AlbertL.LangleyDNTSECTIONBraslow,andJoneF.-CahillUemorlalAeron
2、auticalLaboratoryLangleyField,Va.NACA WARTIME REPORTS are reprintsofDaDers originallyissued toproviderapid distributionofadvance research resultstoan authH AIL5F?ONS OF ?)HF3RENT1- -.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- “- -7.,2 I!JACA AC
3、R No. L5F2.7INTROD?TCT1ONProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I - - .NACA A(3F.NO. L5F27 3seal -pressure -difference coefficient; positivewhe pe.ssure below seal is greater than.pressure above sealaileron section hinge-moment coeffici.ent
4、based()h on aj.leron cb.ord,Clocazqirfil lift per unit spar!. (.)1free - s tr:u-r? CIyn?.?mc pr.ess72re #02/Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-1+Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IH
5、S-,-,-.- .5.dChtotal0h6T - dii in steady rolln response paramater (ref9rence 1)()Gh increment in aileron section hinge-moment coef-6 fici9nt due to ailenon deflection at a constantsection angle of attack(%)A increment of aileron section hinge-moment coef-a ficient due to change in saction angle ofat
6、tack at constant aileron deflectionAcIti incremat of total aileron sect:on hinge-momentcoefficient In steady rollAc aileron section hhe-moxent parameterAso/A6aThe subscripts to prttal derivatives denote thevariables held constant when the partial derivativeswere taken. Ths derivatives wers measlx”ed
7、at zero angleof attack and zero aileron daflectlon.The model had a 2.h-inchchord and a 35.-inch spanld was constructedOf lerdnated malloganywith the excep-tion of the interchangeable a:lerons, which were constructedof solld dural (fig. 1). Ordinates of the NACA 651-2LC air-foil section are given in
8、table I.The three aileron shapes tested are shown in figure2and consist of the true airfoil contour, straight sides,and a beveled trailing edge. The ordinates of the true-ccmtour e.ileronwere the same as the ordinatesEiven Intable I for the trailing-edge art of the NACA 51-210 air-foil section. The
9、contours of th9 straight-aided andbeveled ailerons ware formed by straight lines as shown*In figure 2. A rubber seal was used at the gap at thenose of the aileron.For the tests of the smosth airfoil, the model wasfinished witlhNo. O carbarlmdum paper to produce aero-dyn.smically smooth surfaces. For
10、 the tests of the air-foil with standard leading-edge roughness, the modelProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.- .5.dChtotal0h6T - dii in steady rolln response paramater (ref9rence 1)()Gh increment in aileron section hinge-moment coef-6 f
11、ici9nt due to ailenon deflection at a constantsection angle of attack(%)A increment of aileron section hinge-moment coef-a ficient due to change in saction angle ofattack at constant aileron deflectionAcIti incremat of total aileron sect:on hinge-momentcoefficient In steady rollAc aileron section hh
12、e-moxent parameterAso/A6aThe subscripts to prttal derivatives denote thevariables held constant when the partial derivativeswere taken. Ths derivatives wers measlx”edat zero angleof attack and zero aileron daflectlon.The model had a 2.h-inchchord and a 35.-inch spanld was constructedOf lerdnated mal
13、loganywith the excep-tion of the interchangeable a:lerons, which were constructedof solld dural (fig. 1). Ordinates of the NACA 651-2LC air-foil section are given in table I.The three aileron shapes tested are shown in figure2and consist of the true airfoil contour, straight sides,and a beveled trai
14、ling edge. The ordinates of the true-ccmtour e.ileronwere the same as the ordinatesEiven Intable I for the trailing-edge art of the NACA 51-210 air-foil section. The contours of th9 straight-aided andbeveled ailerons ware formed by straight lines as shown*In figure 2. A rubber seal was used at the g
15、ap at thenose of the aileron.For the tests of the smosth airfoil, the model wasfinished witlhNo. O carbarlmdum paper to produce aero-dyn.smically smooth surfaces. For the tests of the air-foil with standard leading-edge roughness, the modelProvided by IHSNot for ResaleNo reproduction or networking p
16、ermitted without license from IHS-,-,-6surfaces were the same as those ofexceut that O.011-inch carborumiumNACA ACR %0 a71 L5F2?the smooth airfoilPJrainswere appliedto both surfaces at the leadin edg; over G surfnacally smoth surfaces and withstandard roughness applied to ths leadir.gedge.These basi
17、c section data C?EL3be used to predict thesection hinge-momemt chcracteristlca of ailerons of stmilarcontour and chord with any amount of sealed internslbalance by the followlnesesn In fig re 22. Jr.!ncrezse in the Be;nolds rimnberfronlXICtoXICl 6 dccreised the available pressuredifference asross th
18、a aileron seal.Basic for comP.rlson.- T1-erate of roll generated by.the ailerol;has an I“”portenteftect on the htn.gemmentbectiussthe rate of roll .atrstho mean ar.glcof attackat which the ailerar.is orerating. Izr corpnriscn ofailerons .fromsection ata, t,hersfnre,the allsron hire-momer-tcharacteri
19、stics are uually determined ty use ofProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. 0 theoonst”kntllftconcept,that is,”the assumption thatthe aileron portion of the wing acts at constant liftduring a steady roll. n reference 1, however, Gatesand I
20、rving indicated that the constant-lift conceptoverstresses the importance of the hinge-moment parametercha and gave the equation for the rate of change of.theninge-noment coefficient wtth aileron deflection insteady roll as() Cha%lbT chl-n6 cbrat.kerthan(3)(ii)whichis the eqationfor tlhecor.stsnt-ll
21、ftconzept.Altkouh equation () ir “Innciequatefor co-vputiqjfinite-sFan ck.aracteristlc9, it 12 satisfactory oroiring tilethree a.ileraasof different contour. Inrer to simplify tke application of eqwtion (3) tonor-linezrcurves, the c;uation was converted to-1 JA tlcal value of 1/5 l.sgiven for n in r
22、eference 1.The value carrespon:s to ssvsrsl wing-a:leron combffiations,one of r,kichis a wing :ithnn aspect ratio of 9 and with,a C.2C)C qileaon.ilEIVillgan eqqal up-and-down deflection*and extanding fro-lbbpercent semispan to t-newing tip.The value n = was used ii-,equatim (5). Themethod of analysi
23、sused herein is considered suitablefor comparing tha relative merits of the three ailerons.The anasis is presented in tha form of ths aquiva-lant ch.nnein section anQe or attack La. required to -Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-,. ., .
24、 . -. . . . .-. - .-.I12 “ NACA ACR NO. L5F27maintain a constant section llft coefficient for variousdeflections of the aileron from neutral. The hinge-momentACHparameter which is the ratio of the incrementAao/A6asin hinge-momc3nt coeffic!.entin steady roll (equation (5)to the aileron effectiveness,
25、 is plotted against theequivalent change In angle of ettack. The method ofanalysis takes intc account the aileron effectiveness,the hinge moment, and the posstble meckarilcal advantagebetween the controls and the dlerons. The span of theailerons and possible effects of thee-dimensional floware not c
26、onsidered except as indicated in equation (5).The smaller the value ot the M.nga-rnoment parmetwr fora given value of Aao, the more advntageous the combina-tion should be for providing u lower control force for agiven helix angle of the wing tip .Plain aileron.- In order to compare tha plain ailgron
27、of different contour, values of the hinge-moment parameter-a,19)$5.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-w-.,h.NACA ACR No. L5F27 18TABLE IORDINATES FOR ITACA 65;-210AIRFOILSECTION,-Stations and ordinates given inercent of airfoil chordUppe
28、r surface.Station0h“ 3:11:1 9k2* 084. 987. 94?za71 941 899 a71909?2 .9212 .936i3.9182a719 898450.000z5.0140.0265.0z170.0 35 OJ5.04,0.0490:02895.014100.000Ordinate0.8190Lower surfacetation“o?65: 221.3312.5925a71 1027.60610.10615.10120.09125.030.0ZI?5a71 0490.03245.01650.00054.986? a719496 .?7“95rII?.
29、9581.962$Q.9 219L.;6Ordinateoi-. 19-* 59-1*O9-1 z;”;.-2:521-2.92?-3.3.6;.6g1 i-3: 9!.-5.92-3.86i-3.709-3.435-3.075-2.622-2a71 lu-.689-1.191-.711-.293.0100L.E. radius: 0.6G7Slope of radius through L.i.: 0.08425:%n%s+lL.Q-.-L,L.-L_L,.,.IL.-L.L.1, ,.:-,-L.-1. (a) R = 1 X 106.Figure4 .- Hinge-momentclmr
30、aoterlsticsof a sealed-gap0.20cplainaileronof trueairfoilcontourcm an NACA651-210airfoilSection. !msts,IDT81+7,853.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA ACR No. L5F27 Fig. 4b- . _. Provided by IHSNot for ResaleNo reproduction or networ
31、king permitted without license from IHS-,-,-NACA ACR No: L5F27 Fig. 5a.(a) R= 1 X 106.Figure 5 . Pressuredifferenceaoroasthe gap sealof a 0.200plainaileronof trueairfoilcontouron an NACA65,-210airfoilsection.rests,TDT847 end 848. .Provided by IHSNot for ResaleNo reproduction or networking permitted
32、without license from IHS-,-,-NACA ACR No, L5F27 Fig. 5b(b) R=9 x106.Figure 5 .- Concluded.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-wgure 6 .- Dmg characteristicsofaileronOrtrueairfoilcontour.(a) R=l x106.EII NACA651-210airfoil sectionequippedwitha mm.led-gap0.200pla$nlbsts,lDT8)+5,847,and8.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
