NASA NACA-RM-L9E24-1949 Investigation of low-speed aileron control characteristics at a Reynolds number of 6 800 000 of a wing with leading edge swept back 42 degrees with and with.pdf

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1、RESEARCH MEMORANDUM INVESTIGATION OF LOW-SPEED AILERON CONTROL CHARACTEmTICS AT A EtEpNOLDS NCTMBER.OF 6,800,000 OF A WING WITH LEADING EDGE SWEPT BACK 42 WITH. AND WITHOUT HIGH-IJFT DEVICES BY Thomas V. BoUech and George L. Pratt Langley Aeronautical Laboratory Langley Air Force Base, Va. I I I NAT

2、IONAL ADVISORY COMMITTEE FOR AERONAUTICS WASHINGTON July 19, 1949 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. NACA RM LgE24 By Thamas V. Bollech and George L. Pratt An investigation has been carried out at a Reynolds nuniber of 6,800,000 to det

3、ermine the lwpeed lateral control characteristics of a 2re feet wing mean amdynamic chard measured parallel to plane ca root-meaTwquare chord of aileron measured n-1 to aileron hinge Une, feet local aileron chord measured perpendicul.e,r to aileron hinge line C local wing chord measured parallel to

4、plane af spxstry, feet C local wing chord measured perpendicular to 0.273 chord line, feet root-mearwquare chord of hypothetical aileron balance measured ahead of and normal to aileron hinge line, feet h sweep angle of wing leading edge, degrees Y spanwiee coordinate, feet a angle of attack, degrees

5、 %otal arithmetical sun of equal up and down aileron deflections for an assumed set of ailerons C 18 rate of change of r0lLtng-n-t coefficient with aileron deflection % rate of change of aileron hing+manent coefficient with aileron deflection . Provided by IHSNot for ResaleNo reproduction or network

6、ing permitted without license from IHS-,-,-IUCA RM -24 5 . c% rate of change of aileron hing-nt coefficient wfth angle of attack % rate of change of aileron balanchmGsided costour with a II.10 trailing-edge angle measured perpendicular to the Uge lfne. The atileron hinge mcments and aileron loads we

7、re measured by resistanc+ty-pe electrical strain gages. The aileron seal was attached in such mnmr that maments and forces tranemitted to the aileron were negligible. Except for cutouts to allow far the instaUation of strain gages, the seal extended. the full span of the aileron. A total of 12 press

8、ure mifices were installed in the balance chaniber, six above and six below the seal to provide a measurement of the pressure differential across the seal. Details of the aileron are shown in figure 1. The lead” flaps used in the investfgation we of the roundrllose exbnsible type with a con,8taat ch

9、ord of 3.19 inches and extended. frcm 40 to 97.5 percent of the samispan. The deflection of the flaps waa a;pproximately 50 with reapect to the section chord perpendicular to the 0.273 chord line. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-6 NAC

10、A RM -24 Split flap wBTe US. The fences extended frm 5 percent of the local chord to the wing trailing edge. The height of the fences wae arbitrarily set at 60 percent of the thickness of the local airfoil section parallel to the plane of symmetry. 16 Details of the higLI-ift and stallrcontrol devic

11、es are shown in figure 2. The aileron Lateral control characteristics and the wing lift, drag, and pitchingaoment characteristics were determined for the plain wing and the wing equipped wfth high-Uft and stall-control device8 for an angle-of-attack range frm ICo through the stall and for an aileror

12、r- deflection range fram “25O to 25. All data have been reduced to nondimensional coefficient form. Correctiona for support tare and interference have been applied to all force and mcunent data. Je“2Iomdary correctione determined by meane of reference 4 and air-flo-aalimmnt corrections have been app

13、lied to the angle of attack and drag coefficient. In addition, a c Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. Jetrboundaq oorrection has been applied to the pitching mamat. Comections for jehbouPdasg effects on r03Ul.n.n and yam mcrmentB were

14、found to be mall and therefore have not been applied. As ireviously stated, the aileron seal was not contirmous along the span of the aileron due to the installr%tion of the strawge beams. This diecontinuity resulted in scam degree of ldge OSE the seal. A 0allbra.tian of the leakage through the aile

15、ron seal indicated a mge factor E of 0.13- The resultant balanc-harmber pressures presented herein have been corrected to a lO howevm, it may be due in part to the existerne of sane degree of flow separation in the region of the aibron a13 is indicated by the Ilft and moment cha;racteriertics obtain

16、ed. A camparison of the variation of C with angle of attack for 28 wious model configurations (fig. 9) indicates that the va-8 of czg (at S, = 00) were approxhateb the me for an model con- figurations investigated up to an angle of attack of approximately 10 where c for the pbin wing tartd to decrea

17、se. The value of C 26 I mamtept thas carresponding negative deflecticxns. Based up- the results of horieontal-;tail te harever, the higlblift devices caused a. decrease in C in the hfgher mgle-of-attack range. wept for very low angles of attack, the addition of leadiw and trailime flap8 increased th

18、e value of In the case of PR, the addition of highldft devices reduced the values of P in the higher angwttack me and thereby reduced the abrupt hcreased in P obtained for the plain wing. In the 1-r -1- of-attack range the additim of flaps served to increase the values Ra h, pRs *a RQI of P%. The ad

19、dition. of uppeMurface fences produced variations of the aileron hingnnt par c% model configurations investigated axe presented in figure ll. Iarge positive values of Ck:Chs we obtained in the high ang-dttack range far the plain wing and the wing equipped with leading- and trailiwdge flap. The addit

20、ion of uppmurface fences to the latter configuratdon greatly reduced the large values of obtained in the hfgh angl-f-attack range. cha/ch8 Based upon the analysis of reference 8, ValU06 of C in halChS excess of 2.0 are likely to reeult in large values of the ratio of peab f ope obtained at the initi

21、ation of a roll to the steady force in the roll with the possibility of ob3ectionably high stick forces during the rapid initiation and reveraal of an aileron roll. It can be seen frcm figure ll that for the plain wing and the wing equipped with lead- and trai-dge fhps an analysis such as presented

22、in reference 8 would be necessary to insure against the poseibilitr of obtaining excessive stfck forces in any particular design. . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-10 NACA RM w24 A possible highpeed flight arrangement may jacorparate

23、an aileron with a geared tab and no aerodynamic balance. Although thie particular type of design mag prove satisfactory in sane instames, it should be pointed out that high positive values of attained in practice through the we of thie type of lateralcontrol , arrangement It is evident, therefore, t

24、hat a geared-tab arreLngamsnt without aeroQnamic balasce would not prove aatiefactory faor this particular case, inaamuch as it would tend to aggravate the already ChalChs We large positive values of ChalChs- Another approach to the highpeed flight problem is to incorp- rate in the aileron desi- san

25、e degree of aerodynamLc balance. In an effort to show the effect of an internally sealed aerodynamic balance on Chst (the rate of change of aileron hinge moment with deflection in a steady roll), some calculations by means of equations presented in reference 2 were made for various degeea of aerodyn

26、amic ba1anc.e for the configurations investigated and are presented in figure 12. It can be Been that in the cam of the plain wing, the degree of aerodynamic balance required for chgt = o vcxres from appoximstely 45 percent of the aileron chord at a = 0“ to 50 perceat 9.t 3c = 1.6. With flags deflec

27、ted, the required aerodynamic balance varied from apgroximatelg 50 to 30 percent of the aileron chord for angles of attack of 0 and 16O, respectively. With uppercsurface fences installed, the seroaynamic balance required was approximately 50 percent of the alleron chord throughout the eagle-ofettack

28、 range. Aileron lad coefficientsa- The aileron load coefficients aze presented in figures 4 to 6 for the pur-poee of euppuing design infor- mation on the aerodynamic forces that would be anticipated cm a geametrical similar aileron. Due to the Umitatioas of the strain-gage arrangement, it was not po

29、ssible to measure the aileron drag forces p8n%llel to the nlng chord Une and, therefore, no attempt was ”ack range and decreased appreciably in the higher ang-fdttack range for the plain wing ad for the wing fences to the flamed configuration resulted in a more uniform hinge- mament variation. Accor

30、dingly, only for the latter case WE the aeroaynamic-balance requirement essentially conetant throughout the anglMf-a;t;taclc range. with l and Woad, Robert It.: It ko Sweepback of the Lading Edge and Ciromc Airfoil Sections at Reynolda Nwibers af Approximately 6.0 X lo6. WA RM mO7, 1949 0 3 Grab, Ro

31、bert R., asd Kmen, William: IateraL-cmkrol Invest aspect, ratio, 4.01. W r .” . . I Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-14 HACA RM L9%4 Section 6 - 6 h/orged/ -C Figure 2.- Detail8 of wing high-lift and stall-control devicee. Provided by

32、IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. ul r Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-WCA RM LgE2

33、4 .8 .6 -4 .2 czo 0 -. 2 - .4 -. 6 . o/ Cn 0 -.O/ 102 .03 .02 -. 02 . -. 03 - 17 Figure 4.- Aileron chaxacteristics of plain wmg. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-18 NACA RM L9E4 . ,8 .4 0 -. 4 - .8 .a7 ./6 . /2 .Q8 .04 0 ChO -04 * -.a

34、? -. 12 -. f6 -. 20 -. 24 Figure 4.- Continued. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-RACA RM LgE24 .08 .04 cm 0 -. 04 -.08 (c) C, and CL plotted against -a. Figure 4.- Concluded. Provided by IHSNot for ResaleNo reproduction or networking p

35、ermitted without license from IHS-,-,-20 HACA RM L9E24 .6 .4 .2 0 ,2 -. 4 t6 .03 . 02 . o/ 0 *. O/ -. 02 -. 03 (a) Cza, C, and C plotted agabt a. Figme 5.- Aileron clmacteristics of wing with hading- and trailing-edge flaps deflected. Provided by IHSNot for ResaleNo reproduction or networking permit

36、ted without license from IHS-,-,-NACA RM L9E24 21 1.2 .8 -4 0 -.4 -. 8 .04 0 -. 04 -. 08 -. /2 -. /6 (b) % and Ch plotted against a. Figme 5.- Continued. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-22 .04 0 -. 04 -. 08 : 12 8 2i3 V -25 lJACA RM L

37、9E24 . Figure 5.- Concluded. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA RM WE24 .6 .4 .2 0 -2 -. 4 .03 02 .o/ 0 -,O/ TO2 -. 03 -15 -10 -20 Figwe B.-Aileron characteristics of wing with leading and trail- flaps deflected and fences installed

38、. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-24 .8 .a 0 -. 4 -.8 ./6 .I2 .08 .04 0 G -.04 -. 08 : f2 -. /6 -. PO (b) pR and Cb plotted agaimt a. Figure 6.- Continued. . . - . Provided by IHSNot for ResaleNo reproduction or networking permitted w

39、ithout license from IHS-,-,-.04 0 - .w :08 -* I2 Figure 6*- Concluded. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-26 NACA RM L9E24 .o/ 0 -.o / .06 .05 .04 .03 .02 *o/ 0 Uading and Fences trailing-edge f lapa Off Off on Off On On ”- - - ”- 50 3Q0

40、 12O Figure 7.- RoUing-moment and yawing+ament characteristics for eeveral model configurations and total aileron deflectiom. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-WA RM LgE24 c, . .02 .OI 0 YO/ 302 -. 03 .02 .o/ 0 7Of YO2 -25 -20 -/5 -/0 -

41、5 0 5 /O 15 20 25 47 . ?e 8.-w variation of rolling-mament characteristics wit deflection for various model configurations. a Bd ;h aileron Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-28 .m .04 .02 0 -. 02 - .04 .06 .w .02 0 0 7004 -.008 .002 .oo

42、/ 0 “-m ”on orr ”- -. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.08 I ./6 “08 -./2 Figure 10.- The variation of aileron hinge-mmnent characteristics with aileron deflection for various model configurations. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-