REG NACA-TN-659-1938 Wind-tunnel of three lateral-control devices in combination with a full-span slotted flap on an N A C A 23012 airfoil.pdf

1、=)?_J/7,Li_TIND-TUNNEL TESTS OF THREE LATERAL-CONTROL DEVICES INC0_I_II_ATION WITH A FULL-SPAN SLOTTED FLAP ON ANN.A.C.A. 23012 AIRFOILBy Carl J. Wenzinger and Millard J. BamberT_anoley Memorial Aeronautical LaboratoryiNo. 659CA_ E-“| L E iOPNi.i.!I = “_:._,(3 b _;-_ “ “ -WashingtonAugust 1938i=_plu

2、s, down):For the slot-lip aileron,-45 , and -60 .0o .5 _i0 .20 .SO For the plain aileron, -40 , -30 -20 , -I0 , 0 tI0 , 200 , 30 40 50 and 60 For the retractable aileron, 0, up 0.033Zc, 0.0667c,and O.10c.Because of possible structural advantages, narrow-chordretractable ailerons were tested with def

3、lcctions greaterthan the aileron chords so that a gap was left between theupper surface of the airfoil and the bottom of the aileron.O_ue aileron with a chord 0.066Vc was tested up 0.10c, andone aileron with a chord 0.0333c was tested up 0.0518c and00686c. The chords of tho:retractable ailerons were

4、measured along their SUZl_nded are.RESULTSAirfoil Section CoefficientsThe airfoil section coefficients are given in stand-ard nondimen_ional coefficient form as follows:Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4 N.A.C,A. Technical Note i_o. 66

5、9cd 0 ,Cm(a.c.) 0whore Id,m,q,CtC_0 ,section lift coefficient, _/qc.section profile-drag coefficient, d/qc.section pitching-moment coefficient aboutaerodynamic center of airfoil with flapand aileron neutral, m/qc 2is section lift.section profile drag.section pitching momentdynamic pressure, p V 2air

6、foil chord including flap.section _ngle of attack.Aileron CoefficientswhereCha ,haaileron hinge-moment coefficient, ha/(q a_ Sa).is ai.eron hinge moment about the aileronhinge.ca, aileron chord.Sa, aileron area.CL, rolling-moment coefficient.Cn, yawing-moment coefficient.Rolling-moment and yawing-mo

7、ment coefficients for arectangular wing of aspect ratio 6 with one semispan ai-bleron were computed from the two-dlmen_ional-f!ow testsby the following method:r c_, : -o.ooT1/(_c_/a_) _c_ . 1! + !Cn = Cni On owhere Gni = -0.180 C_ c12, and Cno = 0.125 A Cdo.rT_Provided by IHSNot for ResaleNo reprodu

8、ction or networking permitted without license from IHS-,-,-N.A.C.A. Technical Note No. 659 5is the average of the slopes of the liftcurves (gc_ per degree)for the airfoilwith aileron neutral and for the ailerondeflected.the increment in the section lift coeffi-cient produced by the deflected aileron

9、at any given value of angle of attack _.!Cn I ,C%s ,the induced ya_ing-momen% coefficient pro-duced by the Increment of section liftthe average c$ of the airfoil when theaileron is deflected on one side.Cno ! the yawing-moment coefficient due to the in-crenent of profile drag (ACdo) producedby the d

10、eflected aileron.(The constants 40.0071 and -0.180 are taken from“figure 13(a) of reference 6. These constants in-clude the effects of aspect ratio and lift dis-tribution produced by the deflection of the ai-leron on one side. The constant 0.125 assumesthat the profile drag prouced by the aileron is

11、concentrated at the center of the aileronLspan.)Accuracy of ResultsExperimental errors in the results presented in thisreport are believed to be within the following limits:c% 0.02 (near maximum lift) 0.0003 (minimum drag withcd 8f = 0 )C$ 0.005On 0. 002Cha O. 005c_ 0.5 0 to-I.0 8fProvided by IHSNot

12、 for ResaleNo reproduction or networking permitted without license from IHS-,-,-6 N.A G.A Technical Note To 659 |Flap petition 0,002c8 a +0.3 Aileron position - - -0.0003cNo tests were made to determine the effect of flapand aileron fittings on the results. The lift and the draghave beGn correctea f

13、or tunnel-wall effects, as explainedin reforencc 1. The effects of the fittings and the tun-nel corrections probably would nob appreciably change therolling or the yawing moments given in this reportThc given limits of accuracy do not include any un-certainties in the assumptions used for computing

14、C_ wand Cnt. The same relations, howcver, were used in thisreport for all coefficientsDISCUSSIONCharacteristic_ of Airfoil with Slotted FlapThe section characteristics of the airfoil with ai-leron neutral and the _lotted flap deflected are given asplotted against thecurves of c%, Cdo, and Cm(a.C.)os

15、ection angle of attack _o in figure 2. These data aregiven to show the general characteristics of the slottedflap. As previously mentioned, the data were no_ correct-ed for the effects of the aileron and the flap fittings.Aileron CharacteristicsThe rolling-moment, the yawing-moment, and the hinge-mo

16、ment co0fficlcnts computed as previously described aregiven in the form of curves of the coefficients plottedagainst aileron deflection. The coefficients are allgiven for a rectangular wing of aspect ratio 6 with thefull-span flap a_d for a single aileron extending ovcr theentire semispan. The data

17、are given in this form so thatall ailerons will be on a convenient basis for comparison.An indication of aileron performafice may be obtainedfrom the wind-tunnel data by consideration of the followingfactors:4Provided by IHSNot for ResaleNo reproduction or networking permitted without license from I

18、HS-,-,-N.A.C.A, Technical Note No. 669 7i, The value of C_ I should increase with liftcoefficient, i.e, it should increase with angle of at-tack and with flap deflection so that the airplane willhave about the same response for a given control movementregardless of flying attitude,2. The value of C_

19、 wdeflection, and dCst/d8 aleron deflections.should increase with aileronshould be large for small al-3. Lag in rolling motion with control movement shouldbe small, probably less than 1/10 second (reference 7).4. The values of CnV should bo small in any caseand preferably favorable (positive _Then C

20、%t is positive).5. The hinge moments of one aileron should be smallor of such a nature that they can be counterbalancedagainst those of the other aileron through a differentiallinkage.6. The control force required to deflect the aileronsshould be small and should increase uniformly with ailerondefle

21、ction _less a servocontrol mechanism, such as hy-draulic operation of the ailerons, is used.Slot-li_ aileron.- The rolling-moment coefficientsfor the slot-llp aileron are unsatisfactory for the condi-tion from 8f = 0o to 8f = 20o with aileron angles lessthan 100 because about l0 movement of the aile

22、rons fromneutral is required before any appreciable amount of roll-ing moment is obtained (fig. 3). The lag in rolling mo-_ion with control movement is probably less than 1/10 sec-ond, (See references 3 and 4.)The yawing-moment coefficients are generally adverse(negative) for small aileron deflectio

23、ns and favorable(positive) for large aileron deflections. Theme momentsgenerally become algebraically less as the flap angle isincreased (fig, 3).The hinge moments required to hold the aileron neu-tral are large and increase with flap deflections (fig. 4).As the aileron is moved up, the moments chan

24、ge sign andforce must be applied to move the aileron higher. Theslopes of the curves of Cha against 8a arc irregularand, for small flap deflections, they change sign. TheProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-N.A.C.A. Technical Note No. 659f

25、act that the hinge moments are irregular, combined withthe condition that only one aileron is moved, necessitatesa complicated control linkage if satisfactory stick forcezare to be obtained unless a servoco1_trol mechanism is used.Plai_ aileron.- The rolling-moment coefficients forthe plain aileron

26、on the flap decrease with increased flapdeflection. A value of C%v of 0.04 (indicated as a min-imum satisfactory value in reference 6) or larger may beobtained provided that the flap deflection does not exceed40 and that both ailerons are deflected (fig. 5).The values of the yawing-moment coefficien

27、t (fig. 5)would generally be adverse and large, e_pocially _ithl_rge flap deflections.The hinge moments are comparatively small for smallflap deflections but they become large with increasingflap deflections (fig 6) The curves o_ C, against“ “ _ _a8a are fairly regular and, as one aileron i_ moved d

28、own,the other can be made to move up and the moments will bal-ance when 8a = 0. Because the hing? moments increasewith flap deflection, a_)_ appreciable amount of difforon-tia_ would cause ove_balance with flaps deflected.Retractable aileron,- The rolling-moment coefficientsfor the retractable ailer

29、on are satisfactory for flap an-gles of 40 or less (fig. 7). For the flap angle of 50 ,the rolling moments are less than those for the 30 flapangle. The yawing moments are favorable for 0 angle ofattack, becoming less as the angle of attacl_ is increased,and at 12 they are adverse except for the con

30、dition of8f = _, 8a = -0.10c. The hinge moments were not measuredbecause this type of aileron has no aerodynamic hinge mo-ment when the hinge i_ located at the center of the ailer-on radius. It appears that a satisfactory “feel _:for thecontrol could be obtained by placing the hinge axis slight-ly b

31、elow the center of the aileron radius.Figures 8 and 9 show the effects of using narrow-chord retractable ailerons and deflecting them through arange greater than the aileron chord, leaving a gap be-tween the wing and the lower edge of the aileron. In prac-tically all cases the rolling-moment and yaw

32、ing-moment co-efficients wore reduced but the percentage reduction wasloss than the reduction in aileron chord. When the gapbetween the aileron and the wing was too great, a sharpIProvided by IHS Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-N.A.C.A. Technical No

33、te No. 659 9Jbreak occurred in the lift and drag. This break wouldshow as a sharp discontinuity in the curves of rolling-moment and yawing-moment coefficients if plotted againstangle of attack. The break occurred only with the flapdeflected and with the 0.0333c aileron deflected 0.0686c.The maximum

34、anglo of attack at which the break occurredwas 3 with the flap deflected 20 e,The lag in rolling motion with control movement wouldprobably be less than 1/10 second for a retractable ai-leron as far back on the wing as those tested. (See ref-erence 3. )CONCLUDING RE_,_ARKSWhen all factors are consid

35、ered with regard to therolling and the yawing moments produced and of the stickforces desired, the retractable aileron is the only oneof the three ailerons tested that would be satisfactorywhen used in combination with the full-span slotted flap.The retractable aileron may be deflected through a som

36、e-what greater range than its chord with an increase in roll-ing and yawing moment.The plain ailerons on the slotted flap were unsatis-factory because of the small rolling moments and largeadverse yawing moments produced with large flap deflec-tions. The _lot-lip aileron as tested would be unsatis-f

37、actory for lateral control because of the ineffectivenessof the ailerons for deflections lo_z than lO with smallflap deflections. The characteristics of the hinge momentsof the plain and the slot-lip ailerons are such that theyare likely $o cause difficulties in obtaining satisfactorystick forces.La

38、ngley Memorial Aeronautical Laboratory,National Advisory Committee for Aeronautics,Langley Field, Va., July 14, 1938.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I0 N.A.C.A. Technical Note _o, 859I 2w40REFERENCESWenzinger, Carl J., and Harris, Tho

39、mas A.“ Tests ofan N.A.C.A. 23012 Airfoil with Various Arrange-ments of Slotted Flaps in the Closed-Throat 7- by10-Foot Wind Tunnel. T.R. No. (to be published),N.A.C.A., 1938.Wenzinger. Carl J., and Delano, James B.: PressureDistribution over an N.A,C.A. 23012 Airfoil with aSlotted and a Plain Flap.

40、 T.R. No. 633, N.A.C.A.,1938.Weick, Fred E., and Shorta!, Joseph A.: Developmentof the N.A.C.A. Slot-Lip Aileron. T.N. No. 547,N.A.C.A, 1935.Shortal, Joseph A.: Wind-Tunnel and Flight Tests ofSlot-Lip Ailerons. T.R. No. 602, N.A.C.A., 1937.Shortal, J. A.: Effect of Retractable-Spoiler Loca-tion on R

41、olling- and Yawing-Homent Coefficients.T.N. No. 499, N.A.C.A., 19_4.t sWeick, Fred E., and Jones, Robert T.: Resume andAnalysis of N.A.C.A. Lateral Control Research.T.R. No. 605, N.A.C.A., 19_7.Soul, H. A., and _cAvoy, W. H.: Flight Investigationof Lateral Control Devices for Use with Full-SpanFlaps

42、 T.R. No. 517, N.A.C.A., 1935_%Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-_4N.A.C.A. Technical Note No. 659TABLE IOrdinates for Airfoil and Slot Shapes(Stations and ordinates in percent of airfoil chord)llSlotted FlapUpper Lowersurface surfaceN.

43、A.C.A. 23012 AirfoilStationlO152O253O4O5O6O708O9O95UppersurfaceLowersurfaceI. 25 2.672.50 3.615 4,917.5 5.806,437,190-1.23-I. 71-2.26-2.61-2.92-3,507.50 -3.977.60 -4. -87.56 -4.467.14 -4.496,41 -4.175.47 -3.674.36 -3.003.08 -2.161,68 -1.23.92 -.70|lOO .13Leadlng-edge radius:!.58.Slope of radius thro

44、ughend of chord: 0.305.Station0.40.721.362.002.643.925,205.666.487,769.0310.3115,6620.6625.66Center of0.91-1.29-.32.04.611.041.401.942.30-i. 29-2.05-2.21-2.36-2.41-2.41-2.162.532.632.582.461.68.92.!3“4-1.23-.70-.13leading-edge arc:-1.29Leading-edge radius: 0.91(Distances measured fromtrailing edge o

45、f slot llp)Contour of SlotStation Ordinate72.3274.5776.3277.8279.3280.8282.70-I.02.671.762.302.652.822.64Radius of arc: 7.97Center of arc:66.65 4.67.p fh_o$ 2 soaf (dog.) x0I0203O405O608.365.413.832.631,35.50.12Y3.913.633.453.372,431.631.48Provided by IHSNot for ResaleNo reproduction or networking p

46、ermitted without license from IHS-,-,-_ 7IProvided by IHS Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-i.A.O.k. Technioal _ote No.659 Fig. 1 -.=ri= .4v| _-,82“/0 o(a) 8lotted flap, no aileron. ?_70 c (b) Slot-llp aileron.(o) Plain ailoron.,6307 of(d) Retractable

47、 aileron.Figure 1. - Section view of an W.A.O.A. 23012 airfoil.JProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-j_rJ_r2i zv_E_ v_wProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-iii|iI ,+N.A,C.A,Techn

48、ical Note No.659E _ “. :I _ -4 ! _ +_i - _-261 f I / flL_t_J.! _ LL-_zL._ I, -2o 4_.1 -_ _,4, + ltj Jzt -1- t“ - _ .1 I .“ Y l Y .t _- I-t“4 %,_4-_-.!-4 : :-1._ ,_ i.,4.l _,!h114JI-+- i s -_- + _-F- , .-4 Cb-f “-_+-J ,-q _ _- :+f!+. -i -+.!. +_+-.+.+-20 -16 -12 -8 -4 0 4 8 12 16 20Section angle of atiact, ci 0 , de 8.Figure 2.- 5ect_ota lift,dra_,a_d pi_ch_r_5-moment coefficients ofN.A.C.