1、Io=am:-NATIONALADVISORY COMMITTEE mFOR AERONAUTICS -TECHNICALNOTE 2010EFFECT OF HORIZONTAL TAIL ON LOW-SPEED STATIC LATERALSTABILITY CHAR,ACTERISIK!S OF A MODEL HAVING45 SWEPTBACK WING AND TAIL SURFACESBy Jack D. Brewer and Jacob H. LiechtensteinLangley Aeronautical LaboratoryLangley Air Force Base,
2、 Va.WashingtonJanuary 1950Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NATIONAL AD at high es of attack, the contribution ofthe horizontal tail was unfavorable regardless of the horizontal loca-tion. When the horizontal tail was located near the t
3、op of the verticaltail, the contribution of the horizontal tail was highly favorable atlow anes of attack; at high angles of attack, the lkrgest favorableeffect was obtained with the horizontal tail in a forwmd location.The trends obtained with the wing on were similar to those obtainedwith the wing
4、 off, but a large decrease occurred in the favorable effectobtained at large angles of attack with the horizontal tail in the upperposition=; a probable explanation was the detrimental effect of the wingwake arising from flow separation over the wing,-IXTRODUCTIOT7Recent advances in the understandin
5、g ofspeed flight have led to siificant changesthe principles .ofhighin the design of the majorProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-2 NACA TN 2010component parts of airplanes. In many instsnces, consideration isgiven to configurationswhich
6、me beyond the range covered by availabledesi informationregarding stability characteristics. The effects ofchanges in wing design on stability characteristicshave leen exten-sively investigated. In-order to provfde information on the influenceof other parts of the complete airplane, an investigation
7、 of a modelhaving various interchangeablecomponent parts is being conducted inthe Langley stability tunnel. As part of this investigation,the effectof changes in the size and location of a swept horizontal tail on thestatic-lateral+!tabilltyderivatives was determined.T!heeffect of the horizontal tai
8、l has been rather extensivelyinvestigatedpreviously for airplanes having unswept wing and tailsurfaces. As a result of en analysis of test results of several models,some simple rules for estimating the contribution of ccmplete tail con-figuration have been proposed in reference 1. Results showing th
9、e effectof horizontal-tail size and location on the vertical-tail contribution=e presented in reference 2.The present investigationwas made, therefore, to oheck the validiof the earlier enalyses when applied to configurations incorporatingswept wing and tail surfaces.SYMBOLSThe data presented herein
10、 are in the form of standard HACA coef-ficients of forces and moments which are referred to the stabilitysystem of axes with the origin at the pro$ectlon on the plane of Cx =4D at = O% lateral-force coefficient (y/q)cl rollhg+noment coefficient (L/q)cm pitchin X = + “at * =-OY lateral forceLt rolltn
11、g momentM pitching momentN yawing momentdynamic pressuresxeab spen, measured perpendicular to fuselage center linechord, measured paraU.el.tofuselage center linecE mean aerodynamic chordchordwise distance frcxnleadtig edge of wing root chordto quarter chord of wing mean aerodynamic chordchordrise di
12、stance from leading edge of vertical-taillocal chord to 6H/4dchordwise distence from /4 to 6H14z,.Atail length, distence from model mounting pointaspect ratio (32/S)effective aspect ratio, correspondingI_ift+urve.slopetaper ratiosngle of attackangle of yawAe to theoreticalProvided by IHSNot for Resa
13、leNo reproduction or networking permitted without license from IHS-,-,-NACA TN 2010.(f%JHfcJthe quarte-chord line was swept lack 45. The vertical tail was ofithe samesweep, tayer ratio, end section but had an aspect ratio of 1.0.Ordinates for the NACA 65AO08 airfotl section are given in table II.rFo
14、r the yresent investigation,horizontal tails of three differentareas were used, These tails are designated as sH2, H3 (in tieorder of increasingarea) in table I and figure 3. Horizontal tails %.end H3 were tested in only one location (the low middle location).Horizontal tail H2 was tested at three h
15、orizonta3 locations for each ofthree vertical positions, as illustrated in figure 4. b referring tothe horizontal-tail configurations,the letters L, C, andU indicatethe vertical position as being lower, center,_orupper, respectively;and the letters F, M, and R indicate the horizontal location as bei
16、ngforward; midtie, or re, respectively. (Ahorizmh.1 taildesignated (), therefore, represents the horizontal tail of inter-mediate area mounted in the central vertical positian end in the forward .horizontal location.) Most of the fuselage-tail combinationsweretested with and without the wing mounted
17、on the model. A complete list Rof the configurations investigated-isyresentqd in table III. The model was rigidly mounted on a single strutiat the point-shownin figure 2. Forces and moments were measured by meens of a conven-tional six-componentbalance system.A photograph of a complete configuration
18、 is presented as figure 5.In order to obtain the lift-curve slope of the isolated verticaltail, the tail was mounted on a small rod above the strut. The mountingarrangement fothis configurationis shown in figure 6.Tests were made at a dynamic pressure of 24.9 pounds per squarefoot, which corresponds
19、 to a Mach number of 0.13 and to a Reynoldsnumber of 0.71 x 106, based on the wing mesm aerodynmnic chord. Theangle of attack was varied from about “ to 30 for sngles of yawOf-oo snd thecurve is shown to break at an angle of attack of approximately .Correspondingbreaks for the wing-alone tests are s
20、huwn in the pitching-moment curves and Mf%coefficient curves in figure 7 and in the plotsof Cyv and cv (fig. 9). A change in the wing=weke characteristicswould also be expected at-thisangle, and the resultant effects of thevertical and horizontal tails would probably be somewhat erratic.Results for
21、a complete configuration show that negative values ofCnV are provided up.to an engle of attack of .19. (See fig. 9.) Thetendency to become unstable at higher angles is attributmlboth to thebasic instability of the wing at those angles and to the decreasedeffectiveness of the vertical tail due to the
22、 wing and fuselage wake.An increase in Reynolds number or use of a device that would delayseparation from the wing protably would improve thtiirectional stabilityof the complete model at high angles. The positive increase for thecomplete model in Ct$ at a= 0 is provided mainly by the verticaltail; a
23、s the angle of attaok is increased,the moment arm decreases, sothat-the increment and consequently the slope of %* against adecreases.The llft+umve slopes of the wing and-of the isolated verticaLtailare compared with theory in figure 10. Test-swere made on the verticsltail alone (see fig. 6) to elim
24、inate any interferenceeffacts producedby the fuselage or horizontal tail. The experimental lift5suggested for unswept tail surfaces in reference 1.In order to tie these results comparable with unswept-tail results,the more general curves of figure 18 were determined (by interpolationsnd, in some cas
25、es, etirapolation of the curves of fig. 17). The the-retical curve predicted by analyses of unswep+tail results (reference2)is included and shows consistently larger values for the ratio, althoughthe variation with vertical position of the tail was generally similar.The curves presented are for am a
26、ngle of attack of Oo only, and it hasbeen previously noted than an increase in angle of attack generallydecreases the directional stability in the lower and center positionsand consequently reduces the ratio. In the upper positions, an increasein a results in an increase in the value of the ratio to
27、 a valuesubstantially greater than that predicted b theory (for example, inthe UF position the value of F%JH on/%TH off at a= 200was 2.1). These results are further idications of the unreliabilityof present methods (based on unsweptail results at an sngle of attackof 0) in predicting the effect of s
28、wept-tail surfaces on the latelstabflity derivatives.Application to DesignAlthough the present investigationwas conducted with specificwing and tail plan forms and for a specific fuselage, the resultsshould be suitable for nwking estimates of the horizontal-tailProvided by IHSNot for ResaleNo reprod
29、uction or networking permitted without license from IHS-,-,-14 lYACATN 2010contribution to the directional stability ofiany airplane having approx-hately the configuration of the model tested. In the usual case, thetail contribution to directional stability is expressed as+2where is frequently refer
30、red to as the tailqolume coefficient,%and the vertical-taillift-curve slope (%) P msy be obtained fromtheory (such as reference 3) when the sweep angle, the taper ratio, endthe effective aspect ratio A% axe known. The problem, therefore, isto estimate the effective aspect ratio of the vertical tail
31、whenin the presence of the fuselage and horizontal tail. A possibleexpression for the effective aspect ratio of.the vertical tail is asfollows: 1% = F%)H off + % %)H on %)H offwhich also can be written%= V)Hin the1offform()%H on+ %H()%H off 11 (1)The effective aspect ratio of the vertical tail in th
32、e presence of thefuselage ()W H off was found, for the configuration investigated,tobe about 1.17 times the effective aspect ratio of the isolated verticaltail. This factor, however, would be expected to depend on the shapeand size of the fuselage, particularly in the vicinity of the verticaltail. T
33、he effect oftem %)H ) (+ H offfrom figure 18. mehorizontal-tail sizethe horizontal tall is expressed by the1- 1 where(JH on/p%)H off be btained “curves offigure 18 are presented for the specific .(investigated that Is %)= 1.33 and must be%.corrected for any other size by the factor .% “If-variations
34、insize of the horizontal tail are assumed to have the same relativeProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA TN 2010effect on A9 regardless of the horizontal-tall location, thefactor % cen be expressed as1()%H onr)H ff %/% -1()AeVHon 1(%)
35、H off %=1.33%This factor has been evaluatedfromthe solid curve of figure 12(b)which represents the effects of variations in mea of the horizontaltatl, when located at the base of the vertical tail. Values of % determined in this memner, are presented in figure 19.T!bedesign procedure indicatedby the
36、 use of figures 18 snd19 inconjunctionwith equatian (1) csm be expected to apply only at smallaugles of attack. At higher angles of attack, for the horizontal-taillocations below the mfdspan point on the vertical tail, the actualhorizontaltail contribution would bepredicted. For horizontal tails nee
37、rindicated procedure would be expectedat higher sngles of attack.*expected to be smaller than thatthe top of the vertical tail, theto lead to conservative resultsCONCLUSIONSThe results ofen investigationto determine the effect ofhorizontal-tail size end position on the staticlateral-stabilityderivat
38、ives of a complete model with wing and tail surfaces having thequartehord line swept back h” indicate the followlng conclusions:1. Available procedures (based on analyses of unswept tail configurations) for predicting the contribution of a horizontal tail to-Provided by IHSNot for ResaleNo reproduct
39、ion or networking permitted without license from IHS-,-,-.16 NACA TN 2010directional stability,have been found to be unreliable when applied toa tail configurationhaving 45 sweptback surfaces. The effscts ofvariations in area and vertical location of the horizontal tail couldbe predicted qr a probab
40、le explanationwake arising from flow separationLmey Aeronautical Laboratorywas the detrimental effect of the wingover the wing.National Advisory Committee for Aercmautics_eY Alr Force Base, Vs., Septeniber1, 1949.rProvided by IHSNot for ResaleNo reproduction or networking permitted without license f
41、rom IHS-,-,-ImM m 2010.1. Pass, H. R.: dYsis ofWindeland Control. NACA TN 775, 1940.Data on Directional.Stability2. =SY, -E=: Wind-Funnel Dvestigation of End-hate It?fectsofHorizontal Tails on a Vertical Tail Compared With AvailableTheorg.NACA TN105O, 1946.3. DeYoun$, John: Theoretical Additional Sp
42、en Loading Characteristicsof Wings wtth ArbitrW Sweep, Aspect Ratio end Taper Ratio.NACA TN 1491, 1947. 4. Jacobs, Eastman N., andWmd, Kenneth E.: interference of Wiw adFuselage from Tests of 209 Combinations in the N.A.C.A. Variable-DenBi Tunnel. NACA Rep. 540, 1935.5. Goo3 ,19a71 725.ok0.302.004.0
43、0.645-. 00Lo0.64500Quarter-chord sweep angle, degreesDihedral angle, deees . . . .Twist, degrees . . . . . . . . .NACA airfoil section . . . . . . .Area, , sqe fnche “ a71 a71 c a71spen,bH, ties s “ . . . “ s . a71Meen aerodynamic chord, 6H, imhesArearatio, /Sw .9 . .-”Arearati.o, SH/ . . . . s*6fo0
44、Ji.16.10h.110.201.33u. 382.910.100.67 .Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA TN 2010 19TABLE II. ORD12JATESStation and ordinatesStationo.50a71751.252.50R10.015202530:;45505560657075$09095100FOR NACA 65Ao08 -onin percent airfoil chordlO
45、rdinateo.62.75.951.301.732.X?2.432.933.303*593.793*9343.993.90:E3.142.762.351.901.43.96.49.02L. E. radius: 0.408v.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-20 NACA TN 2010TABLE III.- C?ONFIGURATZONSmTIGA!r!ED .wingoff wing onConfiguratica Figur
46、e Confi(1) nation Figure1w 9,F 9 W+F 9F+V 15 W+ F-I-V 15F + (%)IM - -F + (%?)Ill n(a) - -F + (H3) - -F+V+(H) - -F+ V+) U(b) - -/F -t-V + fH3)w - -F+ V+ (H subscripts1, 2, and 3 refer to size (seefig. 3); letters L, C, and U refer to vertical location,and letters F, M, and R refer to horizontal locat
47、Ion(see fig. 4-).a71a71Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-, , .L 7LHZAV7*T/zY7fca%ynJ-!7%4?Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-22.-L. - L .= d7/-.20/U/l 7!.I he 2.-D97ensms oftheuhenszns orem mhe,.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-23H/.1- /3?72Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.-pw/ / / /N-r=-&)fl
