REG NACA-TN-505-1934 The effects of full-span and partial-span split flaps on the aerodynamic characteristics of a tapered wing.pdf

1、. - / d- -.-at“”FT.TECHNICAL NOTESITATI02TALADVISCIRY COl!MITTZIEFOR AEROFIAUt CS . .-.-. . . . .-_-.A No. 505 . . . . -L. -.-. ”.-.-. .Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-!d . . .-NATIONAL ADVISORY COMMITTEE IOR AERONAU!i!ICS. - -. . -.

2、_ :TECHNICAL NOTE NO. 505 -.- . . .-THE EFFECTS OF I!ULL-SPAN .4NJ3PARTIAL-SPAN SPLIT FLAPS ONTIiE AS!RODYNAMIC CHARACTERISTICS OF A TAPER3D fiNctions and deflectingthe lowor section downward for use as a flap. This typoof flap may be used over the Vtiro spqn of hg. wlngl ormay have portions of the

3、flap near the t“ip”cut off for theuse of lateral control devices,. or it may have a sectioncut out at the center “for the fuselage.ea71-The aerodynamic charactorietics of rectangular wingswith full-span and with partial-span split flaps have beenpreviously reported in refrencos 1, 2, and 3. Tho pres

4、-et investigation was made to determine the ch :=,LProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4 Y.A.C.A. Technical Note XO. .5O5:One Feint of interest that-ma:-be noted is that thestall occurs at proressively lower angles of attack withi.nereasi

5、ng flap deflection for the tapered wing with theflaps tested. Thee ffect is most noticeable for tho 0.25ccomtant-chord flap in which case the angle. of attack ofthe stall was reduced from 17 with flaps neutral to 13with flaps down only 30. The rectangular wings with splitflaps did not show this char

6、acteristic but stalled at aboutthe same angle of attack with flaps either neutral or de-flected. (See reference 3.)L/D atcLmex _and CLnax*” The maxtmum lift coefff.- -.=-. . . .- -cients obtained with the tapered wing with the variou6 flaps, and the flap deflections required are shown on fl.g-ure 66

7、 Both tapered-chord flaps give tlgwing somewhathigher maximum lifts than the const-ant-c?ord flaps, andthe tapered-chord flaps %oth give the ving about the samemaximum lift although with different flap deflections.Curves of L/D at Lmax are also given on figure 6for the wing with the different flaps

8、and flap deflections“the steepest glidingtested, This factor is a measure o.anCle attainable with the wing for use in the landing con-dition, the smaller the value the steeper the glide. Themedium-sized flaps would gl.ve the wing shaper angles of-glide than-”the narrow faps-”,the difference being ab

9、out 2.The angle is steepened from 7 with flaps neutral to about13 with the medium-sized flaps deflected.Partial-Span STlit Flaps Tip sections removed.- Curves of CL, CD, and C*PS are given on iguro 7 for the 5:1 tapered tvifig having0.15c- tapered flaps with difforoat equal-length sectionsremoved fr

10、om both tipe. The lift ctirves do not havo assharp a drop just after the, stall as those for partial-span flaps on a rectangular wing (rofErenc 3). lt shouldalso bo mentioned that the .drkg doe not fall of-f nearlyso fast when shor”t sections -of “the tiap”eedflaps aro re-moved from the tips as it d

11、oes in tho CaO of a rectangu-lar wing with split flaps of the same longt”h.Qenter sections rexoved.- !?igure 8 :;ives curves of- -.CL, CD, and c,p. for tlie 5:1 tapered wing having splitflaps with different amounts removed from the center of thespan. In this case the drag variation is more like that

12、*.-3-. *-P,-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IIS-A-A.C.A. Technical Note No. 505 5-*“Y,* .-. .for the rectanlar wing with split flaps”. -cent%r Ofpressure moves forwart% quite rapidly when short sectio,s”are removed from the ceter of t

13、he span, compared with asmall movement when corresponding sections are removedfrom the tips.Comparison of effect of removing. . sections from the .tip a from the center.- Curves of CLmax, and of CD -and L/Ii at CL-X are given on figure 9 for differentflap lengths, both for tip sections removed and f

14、or centersections removed. It should be mentioned that a consider-ation of the flap effects on the basis of flap areas wouldprobably lead to somewhat different conclusions, but in thepresent case the flap lengths seemed to he of the gfeaterinterest and hence are the only ones discussed. Figure 9show

15、s, as for partial-span flaps on a rectangular wing(reference 3) , that a sommhat smaller part of the maximum-lift is lost by cutting off the tip sections than by remo-i+-ing center sections of the same total length.The drag at maxinrum lift, however, is also affectedby the location of the portion of

16、 the flap removed fromthe tapered wing, which was not the case w$th the rectan-gular wing. It will be noted that, as in the case of the.maximm lift of the tapered wing, a smaller part of thedrag at maximum lift is lost %y cutting off the tip sec-tions than %y removing center sections bf the same tot

17、allength.The foregoing characteristics are also indicated bythe curves of L/D at maximum lift shown on figure 9. . Asteeper angle of glide could. be obtained with the taperedwing and flap combination tested by removing sections ofthe same length from the tip rather than from the centerif partial-spa

18、n flaps were required. !This characteristicZs just opposite to that of a rectangular wing with.par-tial-span split flaps.,CONCLUSIONS1. The lift and drag characteristics of a taperedwing with full-span split flaps up to the stall are simi-lar to those of a rectangular wing with flas of compara-ble s

19、izes.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. ._. _.,6 N.A.d. A, Technical Note Eo. 5052. The stall .of a tapered wing with full-span splitflaps occurs at progressively lower ang2es of attack withincreasing flap deflection up to that for CLm

20、ax.3. On a tamered wing, full-span tapered flaps givehigher maximum l_ift coefficients than constant-chordf lapsof comparable sizes.4. The maximum lift and the drag at irtaximunlift ofa tapered wing with a tapered flap extendlkg, over part of,the span is greater, and the L/D at maximum lift is lese,

21、when the partial-span flap is located at the center of thewing than. when it is located at the tip portion,Langley Memorial Aeronautical Laboratory,. National Advisory ComWittee Xor Aeronautics,Langley Field, Va. , September 6, 1934.REFERENCESl, Weick,. I?red l!., and Harris, Thomas A.: The Aerodyna

22、micCharacteristics of a liodel Winq Having. a Split I?lapDbflected Downward and koved to tireRear. T.N. No,422, .,AOCiA, 1932. I2, Wenzinger, Carl J.: Wind.-Tunnel Measurements of Air Loads on Spiit Ylaps. T,No Kc). 498, N,A.C.A. , 1934.3. Wenzinger, Carl J.: The Effect of Partial-Span SplitFl-Secti

23、onshowing flap. .- - . Ib._-_ -. -m. .mABFigure 1.- -splitflaps .on 5:1,tarea . :Clark Ywing.c. .,DProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-,.f.*-N.A.C,A. TechniczilNote No. 505-. Figs.2,3Figure 2.-The 0.15ctapered- Figure 3-The 0.15cconstant-

24、chord splitflapsalong chbrd splitflapsalongentirespan of 5:1tapered wing. entirespan of 5:1tapered wing.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-N.A.C.A. TechnicalNoteNo. 505 F5gs.4,5.-.*“f.iul.b ! . ./ b K-gth,percentagewing spanCDat%=J k“,Tu

25、Fe 9.- Effectof partial-sPansP ltflapaCLmu andon%alatCLX. 0.15ctapered-flapsOn s:ltaperedwing,%- 60.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.N.A.C.A. TechnicalNote No. 505 Figs.7,8, I I/1/, -0.60 u “-0.40 u # :x-0.20” “ + PlainwingtiL”ErnTrml

26、nm 40 al J / “#F-1. -m I I-: 50 w-r- - - I I+fl a.ns=rrrl, i, ,.I It,1-1 1WTK* m. .,L r, ,I I I I I I-16 .-8 0 8 16 24Angle ofattack,degrees,dSplitflapswith tip Figure 8.-Splitflapswithcentersectionsremovedon 5:1tapered wing.Figure 7.-sctionsremovedon 5:1tapered wing.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-