REG NACA-TR-675-1939 Effects of elevator nose shape gap balance and tabs on the aerodynamic characteristics of a horizontal tail surface.pdf

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1、REPORT NO. 675EFFECTS OF ELEVATOR NOSE SHAPE, GAP, BALANCE, AND TABS ON THEAERODYNAMIC CHARACTERISTICS OF A HORIZONTAL TAIL SURFACEBy HARRY J. GOETTand J. P. REEDERSUhlMAR1Results are prented showing the eJects of gap, elevatorno8eshape, balance, cut-out, and tabs on the aerodynamiccharacteristics o

2、f a horisanfai tail surface tested in theN. A. (?.A.1-8cai2 tunnel.2!%epre8enceof a gap caued an 18 percent reduction inthe rariutwn of normal force with el.water de$ection butthe size of the gap (between 0.006; and O.OIOE)was anunimportant factor. At small ekwator de$ectiona, theelectiveness oj aer

3、odynamic balance of the elaabrb inreducing hinge moments was much lamer with .angle of attack of the tail, deg.elevator angle (downward deflection positive).tab angle (downward deflection positive).area.Bpan.chord.average chord.mean square of eIevator chords. “slope of section lift or normal-force c

4、urve(per deg.).alope of W or normal-force curve, elevatorfl-.-ed (per deg.).Subscripts:e, elevator.b, balance.t,tab.Symbols with no subscripts refer to the entire horizontaltail surface.APPARATUSThe tests were conductd in the fullcale wind tunneldescribed in reference 3. The tail surface is shownmou

5、nted in the tunnel jet in figure 1.The dimensions of the tail surface m-e given in figure2. The taper ratio was 2:1 and the locus of the 0.55?stations (the hinge Iine) was perpendicular to the lineDf symmetry. The SJS ratio was 0.41 and the aspectratio was 4.7. The cut-out area was equal to 3 percen

6、tDf the tail area.629Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-640 REPORT NO. 675NATIONAL ADVISOR? COMMIMEE FOR AERONAUTICSRemovable elmmtor-nos ggd stabilizer-tgil blocks(see fig. 3) were provided so that the elevatm balance,the nose shape, an

7、d the gap could be varied. Provisiouwas made for minimum, 10-percent, and 20-percentUIG=E L-Tail Surfe.cemouottih tilefllww.tetunnelbalances with the balance disibuted aIong the span ofthe elevator in proportion to the local chord. With themimmum-bahtnce nose, 4 percent of the elevator areaprojected

8、 forward of the hing% l stabilker area,15.9sq. ft.; fievator me% 11.1sq. ft.; tqw ratio,2Gasmctrat!o, 4.7;dIfOfl S?CtiOn,. A. 0. A. m.line, this arrangement was used for comparison with (4) Minimum bala,nc.e, 0.005z gap, tab Mcctionsmro-bahmce results computed from thin-airfoil them-y. from 0 to 30,

9、 with:The blunt and the tapered nose shapes are show in (a) Full-span tabs.figure 3. The blunt nose was formed .by making the (b) Inboard and middkt tabs,leading-edge radius equal to one-half the section thick- (c) Inboard tbs.ness. Only one nose shape w it has been used for comparison with both (e)

10、 Outboard tabs.the blunt and the tapered noses of the 10- and the2O, (5) 10-percent brtlmwo, tapered nose, 0,005Z twdpercent balances. O.oloz gttps.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-EFFECTS OF ELEVATOR AND TABS ON A HORIZONTAL TAIL SURF

11、ACE W1(6) 10-pwcent balance, blunt nose, 0.0053 and 0.0107gaps.(7) 20-percent balance, tapered nose, 0.0057 andO.O1OZgaps.(8) 20-percent balance, blunt nose, 0.0057 and O.O1OZgaps.MI the foregoing tests vwre conducted at a tunnelair speed of 65 miles per hour corresponding to aReynolds Number of 1,4

12、60,000 based on the averagechord. Further teds between speeds of 25 and 80 milesper hour were made to determine the scale effect onelevator hinge moments.RESULTS AND DISCUSSIONf+oEhiwFoRcE CEfAItACTEIUSmcSThe variation of normal-force coefllcient and chord-force coefficient with angle of attack for

13、various ar-rangements of elevatm balance, nose shape, and gapand for eevator deflections from 0. to 30 is given infigures 4 b 9. The Cc curvw for the O.O1OZgap ar-rangements are omitted because they are the same asthose for the 0.005z gap ascept in the region of thestd.The slope of the normal-force

14、coefficient, dCN/da,for an N. A. C. A. 0009 airfoil of 4.7 aspect ratio and2:1 taper, as computed from the aspect-ratio correctionformula (see the append), is 0.069. This value is tobe compared with the experimental. sope of 0.063obtained for the zero-gap condition (fig. 4), which wasreduced to 0.06

15、0 when a gap was introduced (fig. 5).It wiU be noted that, for elevator deflections up to 10,the deflections, the nose shape, and the gap size had anegligible eflect on the slope, causing not more than aat a/- .30- , II.28.24.4CN G.2 .040-,2 -.04-.4 -.08-.6 -.12d, deg.I?IGUEE7.:Varkdfon of CN and Cc

16、 vrfth a at ver!ous clevgtor deflccllone for 10-peroeutbalonw, bh.mtrim-e,CJ.W5and 0.010?gap.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-EFFECTS OF ELEVATOR AND TABS ON A HORIZONTAL TAIL SURFACE 643.1 I I/.41 1 de,ng. .28,.9 .005. /.6 / / 4c.4(b)

17、.20Computed (fw a,= 0.060-,Lo-4/ / 4.8 , / -/ 476 -/.4.2-0 5 m J5 20 25 30de ,deg.)Mfnkmm balance.(b) l O.*- gap.(n)Tfmerednm.(b) Blunt now.f%uEE 12.-Vedatlon of CA,with=.The elevator-free Lift-curve slopes for all the tailmrangementa with the 0.005Z gap are shown in figure11, The experimental slope

18、 for the minimum balanceis 0.037; the dope computed from thin-airfoti theory is0.03.5. (See equation (2) in rqpdix.) An ilvcsti-gation of a number of other unbuhmced tails, for whichdata are given in reference 2, shows that this C1OSCcorrespondence between the esperimcmtal and thu ,deg.o5 /0 /5-20.3

19、3I IBalance Nose _. I I (Penfl s?005I 8ok7nce(ercent) .?0.; /01 11171(a)f!apcred nom.(b) Blunt naw.FIGUEEM.-VarIatIOrI of CA, WM C,q, a= 0“,omputed slopee is not general. Exporimcnhd slupcsmputed from th results in reference 2 vttriod from5 percent to 40 percent in exc of the computct “ope.Provided

20、by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-13FFECTS OF ELEYATOR AND TAHS ON A HORIZONTAL TAIL SURFACE 645HINGE-MOMENT CHARACTERISTICSThe vmiation of binge-moment coefficient with angleof attack for the various tail arrangements is shown infigure 12. Thes

21、e curves are applicable to both the0.005Z and the O.O1OZgap arrangements because thesize of these gaps caused negligible variations. ThedC#a elope computed from thin-airfoil theory isCh,(a) Ttw=ed nose.(b) Blunt now.FIGUEE15.Variatwn of stk!+hwm criterion C4C6.with Cx fOrnriw tab =anSlruents. a-.0.t

22、)073, which compares with an average expetimental wdue of 0.0045: There appears to be no systematic variation of slope with nose shape, balance, oelevator deflection, these factors causing a spread of umore than the scale effect between speeds of 25 and 80iles per hour (ReynoIds Number equal h 560,0

23、00 to.3 K.2 -. _ -30“ 6, _ -Zo.i -l,=20”.F1OLU?E16.Variat1on of CA with a for mcious deflections0 the full-spantab.1,800,000bused on the average chord) wus found to benegligible.A criterion of balance effectiveness is tho reductitin,.produced in Che fora given thebalancingeffectofthetaperednoses,how

24、ever, variesmarkedly with elevatordeflec-tionbut remains effectivetomuch highervaluesofI%-, -Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-646 REPORT NO. 675-NATIONM ADVISORY tilMMITTEE FOR AERONAUTICStil for the blunt noses. Table I summarizes thb

25、alancing effect of the various balancea and nose shapeaThe relatively close agrewnent of the experimental. .6 / ,c.(a) Full-epautab.(b) Inbaard and mkldle tuba.(o) Inboard tab.IGUM 19.VarlatIonof CL. with CMfor various tab sfmuaud JI/6.MIM. a=.Provided by IHSNot for ResaleNo reproduction or networki

26、ng permitted without license from IHS-,-,-EFFECISOF ELEVATOR AND TABS ON A HORIZONTAL TAIL SURF.4CE 647TABLE IREDUCTION IN Ck. PRODUCED BY VARIOUS BALANCEAND NOSESHAPE ARRM!?GEMEIfTS; 0.0055 GAPFllmt -lo- md-_ 0-%2Q. . . . . or O.O1OZgap.Further tests appear d tihich indicates the variation in eleva

27、tor def.icctiontheir values havebeen determined by the thin-airfoil theory (reference6). The lift-curve slope al is dependent upon aspectratio and plan form.The tail surface teated was designed so that the arearatios of the elevator and the tab corresponded appro.ti-mately to their chord ratios o-re

28、r the span. The perti-nent data and the necessary constants for the computa-tion of the lift and the hinge-moment characteristicsabout the elevator hinge line are:For elevator: For tab:+=0.41. +=0.08.X1= 0.753. X*= O.357.u=o.121.u,I= O.0078. WIZ=O.0175.The characteristics that can be determined (usi

29、ngthe measured value of al =0.060 except asdC.()m= =A1al=0.045=0.047 (for a,= O.063)The elevator-free lift-curve sIope issetting oh.= O. Thennoted) are:(1)obtained byde.() al= =0.035 (2)z Cha.b()I+al doh,() 6.= ual= 0.0073 (3)r%).=-”(%)-lool”l”“)-.W,()(L$, =u&al-vti=-o.020 (6)The sIope of e section

30、lift curve for an IS. A. C. A.0009 section is 0.095, as determined from the datagiven in reference 4. By means of the aspecbratiocorrection formula gi-ren in reference 7,al=f % : 5:yo (7)(wherej=l for the plan form and the shape of the tailsurface tested) a slope of 0.069 is determined for a td”surf

31、ace of aspect ratio 4.7 and 2:1 taper.REFERENCES1. Bradfkld, F. B.: A Collection of Wiid Tunnel Data on the .Balancing of Controls. R. &M. No. 1420, Britich A. R. C.,1932.2. Sikerstein, Abe, and Katzoff, S.: Aerodynrnmio Characteris-tics of Horizontal Tail Surfaces. T. R. (to be published)N. A. C. A

32、. . .3. DeFranse, Smith J.: The N. A. C. A. FnI1-ScaleWind Tun-nel. T. R. No. 469, N. A. C. A., 1933.4. Goett, Hamy J., and Bullivant, W. Kennetlx Tests of N. A.C. A. 0009, 0012, and 0018 Airfoile in the Full-Scale TunneS.T. R. No. 647, N. A. C. A., 193&5. Harris, Thomas h Reduction of Hinge Moments

33、 of Air-plane Control Surfaces by Tabs. T. R. No. 528, N. A. C.A., 1935.6. Perring, W. G. A.: The Tkoretice=l Relationships for anAerofoil with a Multiply Hinged Flap System. R. & M.No. 1171, British A. R. C., 1928.7. Anderson, Raymond F.: Detrxmination of the Character-htias of Tapered Wings. T. R. NO.572, N. A. C. L, 1936.649Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-