REG NACA-TR-611-1937 Wind-tunnel investigation of tapered wings with ordinary ailerons and partial-span split flaps.pdf

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1、WIND-TUNNELREPORT No. 611INVESTIGATION OF TAPERED WINGS WITH ORDINARY. AILERONSAND PARTIAL-SPAN SPLIT FLAPSBY CARL J. WBNZINQHRSUMMARYAn incestigaiim wag made in the i% A. C. A. 7- by10oot wind knn.d to determinethe m-rodmic proper-tix oj tapered wing8 hurnngpartial-span jikps for highlijt and ordin

2、ary ail.emmfor luteralcontrol. Each of twoClark Y un”ngs,tupered 6:1 and 6:3, was egwipped withpartiul-span splii jkps of two Lmgtlk and with ordinaryai?emn.s each has a span of 60 inches anda geometrical aspect ratio of 6.0.The ailerons tapered with the wings, the chord ofeach aileron at any longit

3、udinal section being 25 percentof the wing chord (cJ at the same section. The spansof the ailerons tit tested were the same as those usedin previous tests, 50 percent b/2and 41 percent 6/2 forthe wings tapered 5:1 and 5:3, respectively. Thespans were then reduced to 30 percent bj2 for eachaileron te

4、sted, this latter length being considered theshortest desirable. since earlier tests (reference 6)had shown that the moments caused by both the rightand left ailerons could be separately found and addedto give the total effect with satisfactory accuracy, thepresent models were equipped with ailerons

5、 only atthe right wing tip.733Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. . . - .-.734 REPORT NO. 611NATIONALADVISORY COMMITTEEFOR AERONAUTICSAll the ailerons were arranged to lock rigklly tothe wing at a given deflection or to rotate freely ab

6、outtheir hinge axes, the gap between aileron and wingbeing sealed with a light grease. Hinge moments ofthe ailerons were measured by the calibrated twist of along slender steel rod extending along the hinge axis . . . -LFfl 1.50”L2. the tiective Reynolds Number(test Reynolds NumberXe turbulence fact

7、or of thewind tunnel) was 609,000X1.4=853,000. (See refer-ence 10.) The angle-of-attack range covered fromzero lift to beyond the stall of the wing. Ailerondeflections covered born 30 to 30 and were mens-ured in a plane perpendicular to their hinge axes.(Positive deflections are downward and negativ

8、e,up-ward.)Force tests were made first with full-span flaps onthe wings as a basis for comparison with the partial-span flaps. Lift, drag, and pitching-moment coeffi-cients were measured for flap deflections of 0 and 60.The flaps were next cut to the shortest spans used sothat the longest ailerons c

9、ould be tested first. Withthis arrangement no alterations to the original modelswere required. Lift, drag, and pitching-moment co-efficients were again measured for flap angles of 0and 60, ailerons neutral, and then rolling-, ymving-,and hinge-moment coefficients of the ailerons weremeasured for the

10、 smae two flap deflections. In allthese tests the aileron gaps were sealed with a lightgrease to prevent any leakage because even a smallgap considerably reduces the aileron effectiveness.(roof char7Axis of pitchingmoment, .3 ,! .,- 12.”r k , ._.-. rz 0I J /.+4=9: - -7/4”I!lt- - -1.88) -=-%o=+g%=.-+

11、- e 0600f!% EnlargedviewshowingoilerongoD umealedT.-+lilx“ :GJ-_- _._- Z5 I.JLV226- i. e., the square root of the meanof the squaw of the aileron chords alongits span.q, the dynamic pressure.All coefficients, except those of hinge moment, wereobtained directly from the balance and refer to the wind(

12、or tunnel) rums.The data were corrected for tunnel effects to aspectratio 6.0. The standsrd jet-boundary corrections wereapplied,Aa=6LX57.3, degreeswhere O is the jet cross-sectional area. A value6= 0.165 for the open-jet 7- by 10-foot wind tunnelma used in correcting the test results. An additional

13、correction to the drag data was necessitated by thestrdic-pressuregradient in the open jet. This gradientproduced an additional downstream force on the modelcorresponding to ACD of 0.0019 for the wing tapered5:1 and ACD of 0.0017 for the wing tapered 5:3.EFFECT OF FLAP SPAN ON WING CHAFtACTEBL9Lift

14、and dmqgcoefficients for the 5:1 tapered wingwith various spans of tapered split flap are given inigure 3, and pitching-moment coeflkients in figure 4.Similar data for the 5:3 tapered wing are given hEgurea5 and 6. Values of 0%= and of CD and L/D+V . Q75c.by “Q50b flq2.0In1.6I I I I I N Ie 1, “ ,-m/

15、.4 dPlffllll %FIQUBE3.Lift anddrsgcmffldentsof5:1tapawlwingwfthtapawlt Sopsofvsrfons-qw.mdeflsctedW. Ailmnnentml.Angle of oftack,d .degree.s-/6 -/2 -8 -4 0 4 8 /2 /6 BFIGUEBLPitching-momnt moffldenta of 6:1tapwl wfng with tapered splft flapsof various8P dsfbmxl W. AIlsron nentiat C“ for different fl

16、ap spnns on both the 5:1 and5:3 tapered wings are plotted in figure 7.Some aerodynamic characteristics of the taperedwings with split flaps of various spans are compared intable I with similsr data for a rectanguk wing. (Thedata for the rectanguhw wing were taken from reference3 and corrected for tu

17、nnel effects.) It will be notedProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-736 REPORT NO. 611NATIONALADVISORY COMMITTEEFOR AREONAUTICS22 !llll! 11111 I-A4 flop R2.0: d-0.15(3.bv 1Q59b flop Y e1.8%XIEE 5.-Lift and drag coellldsnts fca 5:3 tqmred w

18、ing with tifmre.i split Sof vaiionu spanadeflectd C. Aileron neutral.Angle of off u ,dqrees-16 -/2 -8:4 0 4 tamnfferonon 5:1 tam wing. Tbe fL16%by 0.703tapered6pW fiam delk%xf 6(P.-24 -16 -8 0 8 /6 24.Aierondeflea%q 8.,degp=FIGURE 14.Hlngemomemt cmflMents of 0.2 i. e., therolling-moment coefficients

19、 are increased and the ad-verse yawing-moment coefhcients are decreased for thesame aileron deflection.Previous tests showed (reference 8) that the longtapered ailerons on both the 5:1 and 5:3 tapered wings,flaps neutral, gave rolling moments equal in magnitudeto an assumed value that would provide

20、satisfactorylateral control up to the stall. At and beyond thestall, however, the indicated control was poor.The rolling-moment coefficient corresponding to theforegoing conditions is approximately 0.065 at a liftcoefficient of 1.0 for the tapered ailerons and wings inquestion. In addition, flight t

21、eats have shown that insome case9 0 =0.04 give9 satisfactory rolling control(reference 11) so that the value of 0=0.066 may betoo high for most of the usual flight conditions.Decreasing the span of the tapered ailerons to 0.30b/2gives an aileron that just meets the requirement ofthe lower rolling-mo

22、ment coefficient on the 5:1 taperedW% which is probably the highest taper likely to bedealt with in practice. The use of the highly taperedwing is accompanied by a decreased damping in rollcompared with the medium tapered or rectangularwings, so that it seems likely that lower aileron rollingmoments

23、 will suflice to give the same degree of con-trol. In addition, the reduction in (?go.ml._-_._ X? 2m 1%:o.m5_ . Lm 14ho.: Eg:2as6 a743 15L1 O.wo.70b_ 1.970 .058144.QoAw- O.w.16$.LWi .6%3 m. 4o.iwb- .lb% L S16 weight of 1 kilogram- k;Power - P horsepower (metric) - -speed-_- V F “ometem per hour- k.p

24、.h.meters per second- rn-p.s-2.GENERAL SYMBOLSEnglish II Iunit I Abbrevi%tion Ifoot (or mile)- ft. (or mi.)second (orhour) - see. (or hr.)weight of 1 pound - lb.VTeight=mg Kinematic viscosityStandard acceleration of gravity=9 .80665 Density (mas9per unit volume)m/s2 or 32.1740 ft./sec.9 Standard den

25、sity of dry air, 0.12497 _gi;-s* atxx - WlVHES= 15 C. and 760 mm; Or0.002378 lb.-ft.-Speciiic weight of “standard” air, 1.2266 kg/m3 or-.Momen of inertia=ml?. ndicate axis of -0.07651 lblcu. ft.radius of gyration k by proper subscript.)Coefficient of viscosi8. AERODYNMC SOVsAbeaor for a modelof 10 c

26、m chord, 40 m.p.s., the correspondingnumber is 274,000)Center+f-presure coefficient (ratio of distanceof c.p. from leading edge to chord length)Angle of attackAngle of dowmvashAngle of attack, hhn.ite aspect ratioAngle of attack, induoedAngle of attaok, absolute (measured from zero-,lift position)Fl

27、ight-path angleProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-zPositive directions of axes and angles (forca and momenta) are shown by arrowsAxisForceDesignation ?%- 5%!Lmgitudinal- . x xLateral - YNormal - z :Moment about axis Angle VelocitiesDesig

28、nation Sbm$ Positivedirection s- n$;:g Anartionaxis)IRolling- L Yz Roll- + u PPitching- M zx Piteh- 0 DYam-rig - N!2x Y Yaw- + w rAbsolute coefficients of moment Angle of set of control surface (relative to neutralCl=$ C.=:8 C=$ position), & (Indicati surface by proper subscript.)(rolliiig) itcliing

29、) (yv?vi&)4.PROPELLER SYMBOLSD, DiameterGeometric pitch P, Power, absolute coeilicient CP=&P)p/D, Pitch ratio c*,TSpeed-power coefficient= b v, Inflow velocityv, Slipstrerunvelocity 7, Efficiencyn, Revolutions per second, r.p.s.T, Thrust, absolute coefficient CT=-&. , (. )Effective helix angle= tan-

30、 &Q, (?Torque, absolute coefficient CO=-& NUMERICALRELATIONS1 hp. =76.04 kg-m/s= 550 f&lb./sec. 1 lb.=0.4536 kg.1 metric horsepower= 1.0132 hp. 1 kg=2.2046 lb.1 m.p.h. =0.4470 m.p.s. 1 Ini.=1,609.35 m=5,280 ft.1 m.p.s.=2.2369 mph. 1 m=3.280S ft.xwlso .Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-