1、Ffc)RESEARCH MEMORANDUMASUMMKRY AND AIWLYSISOF DATAONIHE LIFTAKO HIIWZ+lOMENT CHARACTERISTICS OF CONIROLSTJRFACISUP IUA MACH N7JM6EROF 0.90By John A. AxelscmCOMMITTEENATIONAL ADVISORYFOR AERONAUTICS.WASHINGR)Nril , 1948p37- -Provided by IHSNot for ResaleNo reproduction or networking permitted withou
2、t license from IHS-,-,-.NACA RM NO. Am02 CONFIDENTIALltATIOIULADVISORY COMMITTEE FOR AERONAUTICSA SUMMARY AND ANALYSIS OF WIND-TUNEELAND BIrKaRMoMmTCHmAcmmsmcsDATA ON THE LIFTOF CONTROLSUKEACESUP TO AMACH NUMBEROF O.By John A. AxelsonSUMMARYAn extensive collection of the lift and hingemomsnt charade
3、%istics of omtrol surfaoes up to a Mach number of O. has beenae6enibledfrom hig dees(Seefig. 3.)ratio of the inoluded angle at the trailing edge betweentangents to theedge aze of a(l?wP2) a71Subscriptsf contiol surfacet tabcontio143urface contour o t% trailing-corresponding flat-sided oontrol surfao
4、e,3REDUCTION AND ERESENTATTON OF KESULTSA collection of high-speed wind-tunnel data on control surfacesis presented in this report. It covers a wide selection of planforras,aitioil sections, aerodynamic balanoes, and control- surfaoe profiles. A list of the control surfaoes and theiortant aerodynami
5、c dimensional data is yresented in table 1.For sinrplioity,each control surface and tab for whidh data are.presented is designated by a letter. The plan forms and sectionprofiles of the oontrol surfaces are shuwn in figure 1. Duplica-. tion of results has been avoided in oases were two or morewind-t
6、unnel tivestigations cavered control surfaces of ne=ly identioalcoNFmProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-CONi!IIIENTIAL NtK!ARMNo. A71Q2dimensions and characteristics. IE such cases, only the controlsurfaoe for which the highest test Mach
7、 number was attained hasbeen included in this analysis. Control surface X was tested inthe Langley lnamely, control forces and center-ofravity travel. A slightlynegative c is usually desirable, but if a large travel isrequired for the center of gravity,it is generally necessary touse a positive C in
8、 order to move the stickfree neutral pointaft of the stickfixed neutral point. However, the stick-forcegradient imposes a restrction on the amount of positive C% which. can be permitted, since a positive c tends to heavy the elevatorh3nge moments encountered in flight neuvers.Provided by IHSNot for
9、ResaleNo reproduction or networking permitted without license from IHS-,-,-6 NACA RM NO a71 A7Z02A further restriction is Imposed on the use of positive Cat Maoh numbers well above the critical of an airplane, wherethe use of an elevator etiibiting a large positive Cs control. At both luw and high s
10、peeds, themagnitudes of the hinge moments of the ailerons are affectedlywing csnberj by the differences in the angles of attack of the wingtips during roll, and by the use of unequal up and down ailerondeflections often used to obtain desirable yawing characteristics.There is also a possibility of a
11、dverse control tendenciesaccompanying aileron deflectionwith an airplane operating slightlyabove its critical Mach number, because deflection of the aileronschanges the critical Mach numbers of the wing tips and may resultin local shock+ave formation, separation, and reduced effectivenessof one or b
12、oth ailerons.CONFIIfENTIAL*PProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA RM NO. A7L02 coIu?mEmCAL 7*To avoid the possibility of overbalancing of the ailerons athigh Mach numbers, it is desirable to have a slightly negative Cm7 throughout the
13、erpected operating range of Mach numbers and zeroor sldghtl negative C but it should he noted thatthe aspect ratio was reduced frcm 5.36 to 2.31. The reduction inC was in fair agreement with the general rule that the lift+curve slope is proportional to the cosine of the angle of sweep atsmall amgles
14、 of attack. The large reduction in CL5 can beexplained by the fact that the area of the swept model B wasapproximately 40 percent greater than that of the unswept model A,but the flas were the same size. If the flap effectiveness ofthe two models be expressed in terms of an equal area, the ratio oft
15、he values of b then approximates the cosine rule.In the results shown in figure 6(a), the lift+urve slopes ofthe unswept control surfaces increase with Mach number up to theMach number of lift divergence, the variation being well approxi-mated by the three+iimensional Glauert factor which dependspri
16、marily on aspect z%tio as discussed in reference 15. Theincreases in lifl+mrve slopes with Mach nuder for the sweptsurfaces B and G, however, are much more gradual, indicating thatpossibly the Mch number compomnt perpendicular to the quarter+chord line should be used in computing the quantity (1-W).
17、 meflap effectiveness peraneter shown in figure 6(b) remains rehtivelyconstant with Mach number UI to the Mach number of lift divergence formboth the swept and unswept control surfaces.CONFIIENTIKLProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-8As s
18、hown bymxrfacea A and BcoNmmmTm NACA RM NO. A7L02the hinge+nment characterstics for control sin figures 2(a) and 2(3), sweeping the modelreduced the variations pf hinge+mment coefficientwithcontrol- ?surface deflection and with angle of attack. The reductions in C%and Ch5 accompanied the reduction I
19、n CL5.It might be mentioned that if the choice between swept and unswehorizontal tails was being considered for a given airplane, the area ofthe tail would have to be increased as the swee was increased in orderto provide the same amount of static longitudinal stability at lowhfachnumbers because of
20、 the reduction in tail-plane lift-curve slope withincreasing swee, For an airplane which is to fly at Mach numbersabove 0.85, the use of sweep offers definite advantages by delayingthe effects of ccmrpressibilltyon both lift and hinge mcnnentstohi$ner Mach numbers and by reducing the magnitude of th
21、e changes whenthey Occur. In selecting the amount of sweep to be used, it isdesirable to keep the sweep angle to a minimum in order to maintainhigh C and CL5 over the entire speed range. On the other hand,the gain in critical Mach number from the use of sweep is often only .one-half that indicatedby
22、 the cosine approximationbecause of interferenceat the plane of syumetry and separation resulting frmnthe spenwfse flow of air in the boundary layer inducedby syanwisea71pressure gradients. The interferenceand separation can be reducedby proper contouring of the fusel.age+ing or fuselage-stabilizeri
23、ntersectionsand possiblyby the use of boundarlayer control.but when the thichess of the overhang is greater than that at thehinge line, C while control surface U, which has concave sides and asealed, internal balance, eibits a strongly negative a. Controlsurface K, having the beveled trailing edge b
24、ut the same plan formand nose balance as control surface J, exhibits marked overbalanceat the higher Mach nunibers,as shown in figure 2(k). The balancingeffects of the nose balance and the beveled trailing edge areadditive. Because of the large positive a, control surface Kis not suitable for high+p
25、eed use. In general, the resultsindicate that aerodynamic balances can be used effectively up to aMach nrmiberof at least 0.85 and probably higher,provided the noseshape is properly formed and the thicbes%hord ratio andtrailing+dge angle are kept sufficiently small.Wane for controlling and Chb.- The
26、 results in figures 2, 4,and 5 indicate that the profile of the control surface tit of thehinge line greatly influences and Chb. A bulged or beveled.profile (rl) tends to produce positive C% and Chb, the effectbecoming more pronounced with increasing hkch nuniber. Flat-sided.(r = 1) or cusped profil
27、es (r19Control Surfaces A and G Section A-AB. Figure - Planforms andGontrol Surface Gl- .Gontrol Surfaces A ond BSurface A, B, and Gsection profiles of control surfaces.CONFIDENTIALProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA RM NO. A7L02k.PA
28、7nformGontrol Surface Dt LSection A-A.EFrI /IPhmformsControl Surfaces E and F1- - .ISection B-B =3!=- - -.() Gontrof Surfaces I p 4 1 ) i,1 1 i, III I I M, 080 M, 0,875 (b) Gonfrol swfoce B-8 -4048-4 048 -4 04 8Control-surface deflection, 6, deg.Figure 2 -Voriotion of hinge-moment coeftictent with c
29、ontrol-sutfoce deflection.CONFIDENTIAL.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA RM No. A- CONFIDENTIAL(C) Control SWJ%C8 G29.06004.020:02&M, 0.30 I M,070 I Aft (2775 1.(d.) ,hntrol surfoce D.04 I I I.020702-.04!-ImI1ii, IIM, 0.30 I1-8-404/2 -8 -4 0 4 -8-404Control-surfoce deflection, 6, deg.Figure 2 Continued.CONFIDENTIALProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
