1、. . .MAy261947.-,NATIONAL ADVISORY COMMITTEE FOR AERONAUTICSWIUWIME IuwolrrORIGINALLY ISSUEDSemiber 1942 asAdvance Restricted ReportWIND-TUNNEL IiWESi?RMTIOIVOF CONTROL-SURFACEWARACTERISTIOS.x - A 302ERCENT-cHaRDPIAINmAl?wITHslrRAIGmcONTHENACA 00Ij AIRmrL-= By H. Page Hoggamij Jr.,Ikrley Memorial Ae
2、ronautical lkomto,WY Field, Va.I F -N3?JcEWMHINGTONNACA WARTIME REPORTS arereprintsofpapersoriginallyissuedtoproviderapiddistributionofadvanceresearchresultstoanauthorizedgrouprequiringthemforthewareffort.Theywerepre-viouslyheldunderasecuritystatusbutarenowunclassified.Some thesereportswerenottech-n
3、icallyedited.AU havebeenreproducedwithoutchangeinordertoexpeditegeneraldistribution. .-. -L- 366,a LANGLEy MEMOl?liUAERLNAUrK2u.LABORATORYProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-i lllllllllnmM!llluoll_31176014034509 .INATIONAL ADVISORY OOMMI!
4、I?TEEADVANCE RESTRICTED11 d.FOR AERONAUTICSRXPOET,WIND-TUNNEL ”INVS3STIGATION 03 CONTRCXG-SURBACE CHARAC9!ERISTIOS x - A 30-PER(3ENT-CHO PLAIN FLAP WITH STRAIGHT CONTOUR. -. ON.THE NACA 0015 AIREOIL: “ -:4? .-BY H. page Hoggardj Jr. . -,. . -“ lain flap was greater than for.the-same airfoil with an
5、airfo.il-contou? plain flap of thesame chord. The effectiveness of the straight-contour flapin producing increments of lift was slightly less with.gapat the flap nose sealed and slightly greater with gap .unsealed.than the corresponding values for the airfoil-” .oontour flqit Yor “the straight-conto
6、ur flap, the variationof the flap hinge moment with-angle of attack andith,flap. . . . . . . . . . . : “. . ,. . .$INWkODSJCTIbN : “.:”, ;.-,.,.,. ,. ,. . .The NACA,.,hap.instituted an extensive-investigation of“.the aerodynamic characteristicsof various. flap arrange-ments i-nan-,effo,rt to de,terr
7、ninethe types best suited for.control.surfaces ana to supply experimental” data for . . .- .,. . . . . . . . . .Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-2“ . , .,design purposes. The results of this investigation thatrelate to the present. rep
8、ort are given in refer Gnce 1 andin the reports listed in the bibliography.“1I. .This paper presents the aerodynamic characteristics -of an NAOL 0015 airfoil with”a plain flap having a chord30 percent of the airfoil chord (0.30c) and a straightcontour from the flap nose radius to the trailing edge.T
9、he aerodynamic characteristics of the NACA 0015 airfoilwith the straight-contour f-lapare compared with theaerodynamic characteristics given in reference 1, of thesame airfoil with a 0.30c plain flap having an airfoilcontour from the f$.ap nose” radius to the trailing edge,This plain flap of referen
10、ce 1 will be referred to inthis report as the airfoil-contour flap.lAEPMTUS AND MODELS 1.“”The tests-were made in the I$ACA 4 by 6-footvertical .tunnel described. in reference 2. The test section of thistunnel has been converted from the original open, circular,. 5-foot-diambter jet to aclosed, *ect
11、angulart * bY 6-foo$ .throat for.force” tests of models “in two-dimensional flow.-Athree-component balance system has been installed in the”tunnel in order that forctest measurements of lift, dragand pitching moment may he made. The hinge moments of theflap were mea$ured with.a special-torque-rod ba
12、lance builtinto the model: . . .“ The Z-foot-chdrd. by Precision .,:.The a“ccuracy of the data is indicated by the deviatio?from zero of lift and moment coefficients at an angle ofattack of Oo. The maximum error in effective angle of at-tack at zero lift appears to be about +Q.20. Flap deflec-tions
13、were set within k0,20. Tun”ne3 corrections; eeri-mentally determined in the .,:.,.;,.r .-.7,7,-. .7-s, Ll.”.-,-.,.:”r,.,. ,.-.,-.:Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-5were applied only to lift . The hinge moments arp pI?OIIa-.bly slightly
14、 higher than would be obtained in free airand, consequently, the values presented are consideredconservative . The increments of drag should be reasona-bly independent of tunnel effect, although the absolutevslue is subject to an unkdovn correction. Inaccuraciesin the section data presented are thou
15、ght to be negli-ble reativp to inaccuracies that will be incurred in theapplication of the data to finite airfoils.PRESElTATION 01DATAAerodynamic section characteristics of the NACA 0015airfoil with a 0i30c straight-contour plain flap are pre-sented as funotions of lift coefficient in figure 2. Thec
16、haracteristics with the gap at the flap nose sealed areshown in figure 2(a) and the characteristics iththe ()-()()5cgap are shown in figure 2(b). Part of the data in figure 2are replottpd in figure 3 to show the effect of gap on thevariation of ch with c1 for three typical values ofangle of attack.
17、Increments of section profile-drag coef-ficient caused hy deflection, of the flap are given as .a”function of flap deflection in figure 4.Thp parameters for the straight- and airfoil-contour.flaps are presented for. comparison ”.intable -11. . . . - . .-,. AE30DYNAM1C StiCTION CHARACTERISTICS ,. . .
18、-,Lift .“Figure 2 ind.icat.es that the Lift curves for variousdeflections of the straight-contour flap on the NACA 0015airfoil are of the same ge-neral shape as those for. the air-foil-contour,flap. on the same airfoil (reference 1). Theangle ofattack at which the airfoil stalled was about thesame f
19、or both flap. contours.The slope of the lift curve c1 for the straight- .contour flap was whereas,with flap deflections and large angles of attack of likesign, both unsealed and sealed gaps gave approximately thesame value of lift-coefficient increnent . (See fig. 2.)The curve of lift coefficient as
20、 a function of flap deflec-tion for the straight-contour flap became nonline at flapdeflections greeter than 15 with”the gap sealed and atflap deflections greater than 20 with the gap unsealed.The parameter c (;ree) is a measure of control-freestability. The values of Ct for the straight-Cf.(free)co
21、ntour flap were lower “with the open gap and about the samewith the sealed gap as the values for the airfoil contourflap (table 11).Hinge Moment of Flap The flap hinge-moment curves (fig. 2) for the straight-contour flap are linear over a very small range of anglesof .e.ttack. The curves of the .air
22、foil-contiour flap had the ; .same genaral shape; that is they were nonlinear over mostof the test range.The slope ch and the slope ch for the straight-a 6F .contour flap increased negatively over” he” correspondingvalues. for the airfoil-contour flap. These” increases inCha and c%f for the straight
23、-contour flap are inProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-?-.tqualitztivo agreement with the data of reference 3, whichshow that an increase in the thickness of the after por-tion of the airfoil caused a decrease in cha and %f;conversely, a
24、 decrease in thickness of the after portionof the airfoil, as in the straight-c9ntour flap, shouldproduce an increase in ch aqdc? ch8f-The hinge-moment parameters for both gaps are givenin table 11. Because of-the nonlinearity of the hinge- .moment curves, the parameters ch and Chtb measuredaat a fl
25、ap deflection and an angle of attack f 0, respec-tively, represent the curves over only a small range ofangles of attaqk. The values of the parameters for un-sealed and sealed gaps are indicative, however, of therelative merits of each arrangement . The theoretical ef-fect of asect ratio on the slop
26、es of the curves for flaphinge moment is discusqd in reference 4.For small flap deflections at angles of attack of -8end 0, the straight-contour flap with sealed gap had alarger hinge-mouent coefficient at a given lift than withthe unsealed gap. (See fig. 3.) At all other angles ofattack and flap de
27、flections shown in figure 3, the hinge-moment coefficient for the straight-contour flap with the .unsealed gap was greater. than with the sealed gap. Thi Scharacteristic is also true for the airfoil-contour flap(reference 1) . .“Pitching MomentThe slopes ofthe cureb of pitching-moment coeffi-cient a
28、s a function of lift coefficient at constant flapdeflection snd at constant angle of attack are shown intatle 11. The aerodynamic center was located approximate-ly at the 0.23c station for the gaps both unsealed andsealed . This location of tha aerodynamic center for thestraight-contour flap is in c
29、los”e.agreement with that forthe airfoil-contour flap.The aerodynamic center was expected to move to conversely, adocroase in thickness of the after portion of the airfoilshould cause the aero:.ynamic center to shift toward theProvided by IHSNot for ResaleNo reproduction or networking permitted with
30、out license from IHS-,-,-8.,.trailing edge. A.pparently the change in flap contourfrom airfoil to straight was too small to affect the loca-,tin of the aerodynamic center. .When the circulation was varied %y changing the ef-fective camber of the airfoil, that is, by deflecting theflap, the aerodynam
31、ic center was at the 0.42c stationwith the gap unsealed and at the 0.41c station with thegap sealed. These locations agree approximately withthose for the airfoil-contour flap. The location of theaerodynamic center for deflections of the flap is a funo-tion of aspect ratio (reference 4) and moves to
32、ward thetrailing edge as the aspect ratio decreases. . DragBecause of the unknown tunnel correction, the valuesof drag coefficients cannot be considered absolute; therelative values, however, should le independent of tunneleffect . Inaremonts of drag coefficient, plotted as afunction of flap deflect
33、ion in figure 4, were determinedby deducting the drag coefficient of the airfoil with the “flap neutral from the drag coefficient with the flap de-flected, with all other factors constant. At positiveflap deflections and at angles of attack of 0 and .-.: ,.=.”. -:. ,”.-e. : ,.- ,: . .+.:. J.: : :- -
34、 ,. . ., :.,. ,. . “ . “.:-,:.:-,. .n.,.,. , . . .,Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-9flap of the same chord indicate the following conclusions:,1. The slope of the lift curve,for the airfoil withthe straight-contoub plain flap was grea
35、ter than for thesame airfoil with the airfoil-contour plain flap.%, 2. The lift effectiveness of the straight-contourplain flap was slightly less with gap sealed nd slightlylarger with gap tms.ealed than the” lift effectiveness ofthe airfoil-contour flap with the sbme gap conditions. 3. For the stra
36、ight=contour flap, the variation ofthe flap hinge-mQment coefficient with angle of attack .and with flap deflection vas larger than for the airfoil-”contour, flap.4. The location of the aerodynamic center for.thestraight-contour flap was in close agreement with thelocation of the aerodynamic center
37、for the airfoil-contourflap.5. The atrfoil had approximately the same drag char- .acteristtcs for both fIap contours. “Langley Memorial Aeronautical Laboratory, “ “-National Advisory Comm$ttee for Aeronautics,Langlpy Field, a.RI!YERENCES “1, Sears, “Richard I., and Liddell; Robert B.: lind-TunnelInv
38、estigation of Control-Surface Characteristics.VI - A 30.Percent-Chord Plain Flap on the EACA 002.5Airfoil. NACA A.R.R., June 1942.2. Wenzinger, 0ar3 J, and Harris, Thomas A.: The VerticalWind Tunnel of the Ntitiona Advisory Committee forAeronautics , Rep. No. 387, NACA, 1931.Provided by IHSNot for R
39、esaleNo reproduction or networking permitted without license from IHS-,-,-. . .,.I.o ,. .3. Jones, Robgrt T.+ anAmes, Mi.ltn B:, Jr. : Wind+ Tunnel ,Investigation of Control-Surface Characteristics,v - The Use of a Beveled Trailing Edge to Reduce theHinge Moment of a Oontrol Surface. NACA. A.R.R.,.
40、.ach 1942. - - .“4-. .Junes, Milton. B., .Jr., -and Sears, Richard 1.:. Determi-.,nation. of Control-Surface Characteristics from NACAPlain-Flap and Tab Data .Bep. No. 721, NACA, 1941.BIBLIOGRAPHY -. . ,Sears,. Richard I., and “Hoggard, H. Page, Jr.: Vind-Tunnel “Investigation of Control-Surface Cha
41、racteristicsII - A Large Aerodynamic Balance of Various Nose Shapeswith a 30-Ferc6nt-Chord- Tlap on an NACA 0009 Airfoil.NACA A.R.R., Ug. 1941. . .1 . Ames, Hilton B., Jr.: Vind-Tunnel Investigation of Control-, Surface. :Characteristics . III - A Small AerodynamicBalance of.Various ?Io6ei.Shapes .U
42、sed with a 30-Percent-Chord Flap on an NAGA 0009 Airfoil. .N.4GAA.R.R.,Aug. 19417Ames, Milton B., Jr., and Eastman, Donald R., Jr.: lTind-Tunnel Investigation of Control-Surface Characteristics.17 - A Medium Aerodynamic Balance of various NoseShapes Used with a 30-Zercent-Chord lYlap on an NAC4. .00
43、09 Airfoil. . NACA A.R.R.$ Sept. 1941. . . . . . Se.H. Page, Jr.: . !?imd-TunnelInvestigation of Control-Surface Characteristics.VII - A l!editimAero.dy.namlc Balance of Two Nose Shapes. .Used with a 30-Percent-Chord Flay on an NACA 0015 Air-. .foil. NACA +.R., Jdy 1942. .,.sears, Ilichard l., “and
44、Gillis, Clarence 1.: Wind-Tunnel .-Investigation of ControlSurf&ce Ch=.ractoristics.VIII - A Large Aerodynamic Balance of TWO Nose Shapes ,Used with a 30-Percent-Chord Flap on an NACA 0015 Airfoil. WCA A.R.R., July 1942. %,- -1 ,z.: . . . . , ,:T. -, . . . . . . . - ., . .= .y . . ., .,-. -. :*”:,.:
45、-7Y-n- - -. )-. -., - -. , -, . - -, .-: ,.=:- . j. *.: f.,. . . - , :,:,. ,“,. , . . . . -. .Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.TABLE I. - ORDINATES FOR NACA 0015 AIRYOILStations and ordinates in percent of airfoil chordo1.252.557.5101
46、52025304050607080909510010002.373.274.445.255.856.687.177.437.507.256.625.704.583.281.811.01(.16)o1qLowersurfaceo-2.37-3.27-4.44-5.25-5.85-6.68-7.17-7.43-7.50-7.25-6.62-5.70-4.58-3,28-1,81-1.01(-.16)oL. E. radius: 2.48. .Provided by IHSNot for ResaleNo reproduction or networking permitted without li
47、cense from IHS-,-,-12.,.-.!l?ABL3!II. - PARAlTER VALUES FOR 0.30cST13LIGH!&Al?D AIRFOIL-CONTOUR PLAINFLAPS ON AN NACA 0015 AIRFOILStraight* oontour flap Airfoil-contour flapParameter 0.005i? gap Sealed gap 0.005c gap S8aled gap Ia%()-0.470 .-0.560 -0.460 -0.580 .-% CT.J .090 .098 .089 .096am f(j$ .0
48、71 .081 .075 .080free ,./(-)acm .024 .017a71 020 .020a% ef)acm -.168 -,155 -.170 -.155actaacfaq!J -.0039 -.0028 -.0022 -.00236faCh) f -.0084 -.0089 -.0063 -.0080,a8fa.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.,/. .:,. . ., )!1.!.,i+ - C =2#- - zR=.045&. Chord he .01232# G$p =.OwcP- cf=30c *F/
