NASA NACA-RM-L52A23-1952 Preliminary investigation at transonic speeds of the effect of balancing tabs on the hinge-moment and other aerodynamic characteristics of a full-span flappect.pdf

1、 RESEARCH MEMORANDUM PREIJMINARY INVESTIGATION AT TRANSONIC SPEEDS OF THE EFFECT OF BALANCING TABS ON TI33 HINGE-MOMENT AND OTRER AERODYNAMIC CHARACTERISTICS OF A FULL-SPAN FLAP ON A TAPERED 45 SWEPTBACK WING OF ASPECT RATIO 3 By Vernard E. Lockwood and Joseph E. Fikes “_“ “ - y “ -%j“-j4J$/1:* “ se

2、e “ 7 “- “-“- “romxslm NATIONAL ADVISORY COMMITTEE Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-iG n I NATIONAL ADVISORY C0M“EZ FOR AERONAUTICS RESEARCH ME“ HiELlMINARY INVESTIGATION AT TRAFEONIC SFEJDS OF THE AND OTHER AERODYNAMIC CHARACTERISTICS

3、 OF A WING OF ASPECT RATIO 3 By Vernard E. Lackwood and Joseph E. Fikes An investigation was made at tranaonfc speeds of the control balancing characteristics of three tabs on a full-span flap on an aspect-ratio-3, 45O sweptback wing. The investigation was made in the Langley high-speed 7- by 10-foo

4、t tunnel utilizing the hfgh-velocity flow field generated over a reflection plane on the side wall of the tunnel. The results indicated that all the tabs tested, inset, attached, or detached, would balance the flap hinge moments throughout the speed range. The inset tab showed the greatest loss in l

5、ift and the detached tab generally showed the least loss in lift and would have the met constant ratio of tab deflection to flap deflection throughout the speed range. INTRODUCTION The lack of infomation on the aerodynamic balancing of controls in the transonic-speed r-e has led to the installation

6、of powerful boosts in the control syatem of airplanes to enabLe the performance requirements to be met. The power-boosted control, although quite successful from the standpoint of effectiveness, has some disadvantages: The required mechanism occupies considerable space which with the thinner wings c

7、ould become critical, considerable power is required to operate the control system, and a manually operated control system must Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-often be provided in addAtion to the power boost for positive control in t

8、he event of boost failure. It is quite possible that the size of the boost might be materially reduced or even eltminated entirely if more information were available on methods of aerodynamically balancing controls at transonic speeds. The National Advisory Committee for Aeronautics is engaged, at t

9、he present time, in a research pngram designed to provide more Wormation on this. subject. One method of balance which has been successful at low speeds and which might be adayted to present-day high-apeed aircraft is the balancing tab. It was the purpose of this investigation to determfne whether a

10、 balancing tab would maintain its effectiveness through the transonic-speed range. No attempt has been made to provide design information by varying the tab geometry other than to change the chordwise location of the tab. The three tabs used in the investigation had the same plan form which consiste

11、d of a rectangular lifting surface attached to or near the flap trailing edge. The half-span tabs were centered along the flap span. The chordwise positions in which the tabs were tested are indicated by their respective names: inset tab, one which lies within the plan form of the main control; atta

12、ched tab, one attached to the control trailing edge; and dgtached tab, one which is located behind the control and supported by booms. Lift, rolling-moment, and hinge-momnt characteristics were obtained over a llmfted angle-of-attack and deflection rmge at Mach numbers from 0.7 to 1.1. cL chf S com1

13、cIEms AM3 SYMBOLS lift coefficient (Twice semispan lif%/qS) flap hinge-moment coefficient (Flap hinge moment about hinge line of flap/q2“ ) rolling-moment coefficient about axis parallel to relative wind and in plane of symmetry (Rolling mollbent of semispan model/qSb) twice wing area of baaic semis

14、pan model, 0.202 square foot twice span of basic semispan model, 0.778 foot mean aerodynamic chord of basic wiQ, 0.269 foot Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NXA RM L52A23 i 3 M area moment of flap (wit there- fore these data may repree

15、ent an overbalanced condition. In maneuvering flight, the negatfve values of chr, shown in figure 14 would aid in reducing the hinge moments of the controls and therefore less tab deflection would be required resulting in greater lift or roll effective- fa than those of the inset tab (fig. 14) there

16、fore the effect of maneuz vering flight would be more pronounced on the attached and detached tabs than on the Wet tabe. For steaQ- flight the negative values of Chr, might either reduce or increaee the hinge moments depending on the trim and stability characteriatice. The tab arrangement investigat

17、ed represents a rather unusual tab- linkage mechanism, that is, one in which no tab moments are transmitted outside of the flap. An example of such an arrangement is one in which an electric motor within the flap actuates the tab proportional to flap deflection. For the more conventional arrangement

18、s, a knowledge of the tab hinge moments is necessary before aqy tab balancing system can be evaluated. It is probable that the magnitude of the tab hinge P“-nts at transonic speeds may be such that aerodynamic balancing of the tab will be required if the system is to be manually operated. An indicat

19、ion of the amount of useful control that can be accom- configurations is given in figure 10 by the parameter . The inset tab appears to be an ineffective device at angles of attack of Oo, 2O, and 4 ae the lift retained after balance has been achieved is small particularly at Mach numbers of 1.0 or a

20、bove. “his loes in lift effectiveness ia in agreemerrt with the two-dimensional theory of reference 1 which shows that when an inset Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-2G NACA RM L52A23 9 - tab is used to make Ck = 0 at supersonic speeds

21、 it also results in C% = 0. - Because the lift effectiveness of the flap with the attached tab Chf is generally greater through the range of test condittons than for the other two tab configurations, it might be expected that this configuration would have the most lift retained for useful control. T

22、he large ratios of %/6f required for trim, however, materially reduce the value of the parameter . The detached tab because of its comparatively small values of 6t/Sf generally results in hvhg the maxlmum lift available for control, particularly in the transonic- speed range. ($)chf=* The efficiency

23、 of the controls in lift which is given by the ratio qC;o) to cLsf is compared in figure ll. The detached tab shows the greatest efficiency which is about 80 percent for the range of test conditions investigated. Values of the efficiency for the other two tabs are generally less and show considerabl

24、e variation with Mach number. - The rolling-moment pazameters presented in figures 12 and 13 indicate about the same results as the lift parametera except perhaps that the parameter la about equal for the attached and - detached tab. coI?cLusIoNs An investfgation at transonic speeds to determine the

25、 balancing characteristics of an inset, an attached, and a detached tab on a Ml- span flap of a sweptback wing indicated the following conclusions: 1. A11 three tabs were capable of reducing to zero the flap hinge moments resulting from deflections of the control. 2. The inset tab showed the greates

26、t; variation in tab-flap deflec- tion ratios and the greatest loss in lift for zer.3 flap hinge moment; whereas the detached tab showed the lowest values of and the least varia- for zero flap hinge moment. - tion in tab-flap ratios and also showed generally the least loss in lift c Provided by IHSNo

27、t for ResaleNo reproduction or networking permitted without license from IHS-,-,-10 - NACA RM 5223 3. The hinge-moment variations with angle of attack for the attached and detached tab were much greater than those of the control with the inset tab .and the variations were in the direction to reduce

28、the control forces in maneuvers. Langley Aeronautical Laboratory National Advisory Committee for Aeronautics Langley Field, Va. REFERENCE 1. Tucker, Warren A.: Notes on Geared Tabs at Supersonic Speeds. NACA RM L7Lo4, 1948. Provided by IHSNot for ResaleNo reproduction or networking permitted without

29、 license from IHS-,-,-NACA RM L52A23 - ll Y I I I Figure 1.- Basic wing model mounted on the reflection plane in the Langley high-speed 7- by 10-foot tunnel. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. . . . . Inset tob Attuched tub Detodrw fub

30、 .%fb A-A *trim A-A sect4n A-A I . - Figure 2.- Details of the controls tested. (All dimensions are in inches.) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I 1 I Figure 3.- View of typical. model rmunted on the reflection plana in the Langley hig

31、h-speed 7- by l0-foot tunnel. W P Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.- W.93 6 4 2 0 4 p ma- P 4 6 4 4 2 B- 2 4 6 Figure 4.- Typical NwJ-I amber contours mr the side-nall reflection plane in region of lllodel location. .- . - . . Provide

32、d by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA RM L52A23 . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-16 C 0 0 0 0 0 .2 Chf 0 -2 0 l0 Atfuchted tub sf= -19.5“ (a) ch against Figure 6.- Typical dat

33、a plots from which the lift, hinge-moment, and rolling-moment parameters were determined. M = 0.80. Flagged symbols indicate data obtained with the tab deflected. - Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3G - 8 - LO .8 6 cr 4 -2 0 72 0 10 Af

34、fuched tub st = - /9.5O 0 10 Sf deg (b) against 6,. Figure 6.- Continued. Detached fub sf = -20.uo Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-18 NACA RM L52A23 . /o -08 .a5 cz 104 .02 0 -* 02 0 10 8f ,dep (c) Cz against 6f Detached tab = -2O.U“

35、Ffgure 6.- Concluded. . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. . I I I U 1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-20 - NACA RM L52A23 . Tab Q Inset CI a = “bo. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-i i c c Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-