NASA NACA-TN-4077-1957 Static longitudinal and lateral stability characteristics at low speed of 45 degrees sweptback-midwing models having wings with an aspect ratio of 2 4 or 6《低.pdf

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1、,*NATIONAL ADVISORY COMMITTEEFOR AERONAUTICSTECHNICAL NOTE 4077,STATIC LONGITUDINAL LUU3IdiTERALi STABITJTYCHARACTERISTICS AT LOW SPEED OF 45 SWEPTBACK-MIIXVINGMODELS HASZINGWINGS WTIH AN ASPECT RATIO OF 2, 4, OR 6By David F. Thomas, Jr., and Walter D. WolhartLangley Aeronautical LaboratoryLangley F

2、ield, Va.WashingtonSeptember 1957.-:. ,Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TECHLIBRARYKAFB, NMNATIONAL ADVISORY COMKHTEEIilllllllllululll:lllllllllllFoR AERONAUTICS nDkh748TECHNICAL NOTE 4077STATIC LONGITUDINAL AND LATERALCHARACTERISTICSA

3、T LOW SPEED OF 45 SWZPTI?ACK-MIDWINGMODELS HAVING WINGS WITH AN ASPECT RATIO OF 2, !, OR 6Ey David F. Thomas, Jr., and Walter D. Wolhartm!4MARYA systematic investigation was conducted in the Langley stabilitytunnel to determine the effects of the various components and cotiina-tions of components on

4、 the static longitudinal and lateral stabilicharacteristicsat low speed of a seri-esof 45 sweptback-midwing-airplaneconfigurations having wings with an aspect ratio of 2, 4, or 6.The results of this investigation have indicated that the wing-ontail effectiveness in producing negative pitching moment

5、 increased withaspect ratio and angle of attack-and became approximately eqwl to thewing-off value at very high angles of attack. Also, all complete modelstested became directionally unstable in the high angle-of-attack rangemimarilv as a result of increased losses in the stable contribution ofhe ta

6、il-both with angle of attack and increasing wing aspect ratio.INTRODUCTIONIn general, at low angles of attack satisfactory estimates of thestability characteristics of midwing or near-midwing airplanes havingbodies of revolution may be made by use of procedures such as thosepresented in reference 1.

7、 At moderate to high sngles of attack, how-ever, reliable estimates sre difficult, if not impossible, to makebecause of the unpredictable interference effects between the miouscomponents of the airplane.Experimental data are available froina number of sources concerningthe static stability character

8、istics of the unswept-wing case and theswept-wing case (for example, refs. 2 to 8). These data show the influ-ence of such geometric variables as tail sxea, tail length, fuselagecross section, wing location, and others. The effects of wing aspectratio on the stability characteristics for wing-alone

9、and wing-fuselageconfigurations me given in references 9 to 13. Little systematicinformation, however, is available concerning the effect of wing aspectProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-2 NACA TN 4077ratio on the contributions of wings,

10、 fuselages, W tails to the stability Acharacteristics of complete models. In order to provide this informationan investigation (ref. 2) was conducted in the Langley stabili tunnelon a series of unswept-midtingmodels having interchangeablewings of.aspect ratio 2, 4, or 6.The purpose of the present pa

11、per is tQ extend the results of theunswept-wing investigation of reference 2 to include the static longi-tudinal and lateral stability characteristicsfor a series of45 sweptback-midwingconfigurationswith wings of aspect ratio 2, 4,or 6. Data are presented for an angle-of-attackrange from -4 to 32.Th

12、e effects of wing aspect ratio on the contributions of the variouscomponents to the static longitudinal and-lateral stability characteris-tics are presented with particular emphasis on the influence of the com-ponents, singly and in combination, on the tail contributions.SYMBOLSAQ data are referred

13、to the stability system of axes with the ori-gin at the projection on the plsme of”symmetry of the qparter-chordpointof the wing mean aerodynamic chord. Positive directions of forces,moments, and angular displacements are shown in figure 1. The coeffi-cients and symibolsare defined as follows:A aspe

14、ct ratio, sb span, ftc local.chord, ftJb/2E mean aerodynamic chord, C%y, fto1 tail length, distance measured parallel to fuselage referenceline from mounting point to ?5/4of the tail (same for verti-cal and horizontal tail), fts surface area, sq ftx location of quarter-chordpoint of local chord, mea

15、sured fromleading edge of root chord parallel to chord of symmetry, ftz location of quarter-chordpoint of mean aerodynamic chord,measured from leading edge of root chord parallel to chordrb/2of Sylmlletry,2so Cx ay, ftProvided by IHSNot for ResaleNo reproduction or networking permitted without licen

16、se from IHS-,-,-NACA TN 4077TY spanwise distance measured from andof symmetry, ftperpendicular to plane3F spanwise distance to mean aerodynamic chord, measured fromCDCLCyC!mCn2Jb/2and perpendicular to plane of SYrIUEtW, Wmfftospanwise distance along vertical tail measured from and per-pendicular to

17、fuselage reference line, ftspanwise distance along vertical tail to mean aerodynamicchord of vertical tail, measured from and perpendicularbvto fuselage reference line, + J CZ dz, ftv o1 lb/q.ftfree-stream dynamic pressure, P jfree-stream velocity, f%/secspanwisedensity,angle ofangle ofcomponent of

18、free-stream velocity, ft/secslugs/cu ftattack, degsideslip, defined as sin-l Y degVJapproximate drag coefficient, Dr%qlift coefficient, theprinciple dimensions of the complete models are shown in figure 2.Sketches of the plan forms of the three 45 sweptback wings of aspectratios 2, 4, and 6 used in

19、this investigation sre shown in figure 3.Ordinates of the fuselage and the NACA 65A8 airfoil section used forthe wings smd tail surfaces are presented in table II. The fuselagewas circular in cross ection in planes perpendicular to the fuselagereference line.In this investigation the horizontal and

20、vertical.tails were testedas a unit at all times. In the absence of the fuselage, the tail groupwas mounted on a boom in the same position relative to the moimtingpoint (5/4 of the wing) that the tail occupied in the presence of thefuselage. A complete-model configurationand a wing-tail configuratio

21、nmounted on a single-strut support sre shown inTESTS AND CORRECTIONSTests for this investigationwere made atfigure 4.a dynamic pressure of24.9 pounds per square foot which corresponds to a Mach nuniberof 0.13.The Reynolds nunibersbased on the wing mean aerodynamic chord were1.00 x 106 for the aspect

22、-ratio-2wing, 0.71 x 106 for”the aspect-ratio-4wing, and 0.58 x 106 for the aspqct-ra;io-6ting.The longitudinal characteristics , CL, and %1 were,determinedfor an angle-of-attackrange of -4 to 32. The sideslip derivatives. c% c% d C% were determined for this range of angle of attackby using values f

23、or angle of sideslip of 5 and -5.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-6 NACAm 4077.The angle of attack, the drag coefficient,and the pitching-momentcoefficienthave been corrected for jet-boundaryeffects by using approx-imate correctionsbas

24、ed on unswept-wingtheory and in the manner suggested .in references 14 and 15. Tare correctionshave been applied only to thewing-on basic longitudinal data Cm, , and . The data have notbeen corrected for blockage.PRESENTATION OF RESULTSThe results of this investigationare presented as coefficients o

25、fforces, moments, and derivativesplotted against angle of attack for thevarious model configurations. A summary of the configurationsinvesti-gated and of the figures that present the data for these configurations,together with the purpose of these figures, is given b %he”followingtable:Data(plotteda

26、gainsta) I Configuration IFigure% % %(%)VH L 7c% % C%W,WF,WVE,WFVE 10IF, VII,FVHI 11()CYD E1.2()cp VH . 13VH,()%B FVEF, tiMRHk15Purposeoffigureta elm -Effectofthevariousmcdelcmq?onentssinglyandincombinationonthebasiclongitudinaldata.Effectof thevariousmodelcomponentson thetailcontributionto longi-tu

27、dinalstebili.Effectofwingaspectratiom thetailcontributionto hltUdiZld stabilitywtthorex flow from the wing; whereas, at high angles of attack decreased(%)positive and even negative C is a result of unfavorable sidewash.At high angles of attack the higher aspect-ratio wings inflictgreater losses in t

28、ail contribution to directional stability than do thelower aspect-ratio wings, either with or without the fuselage.The fuselage exerted a destabilizing influence on the tail contri-bution at low and.moderate angles of attack with and without a wingpresent (fig, 13). At high angles of attack, however

29、, the $uselage hadsomewhat of a stabilizing effect on the tail. Also, the addition of thefuselage to the wing-tail combinationproduced a stabilizing effect onthe tail contribution to directional stability at high angles of attack(fig. 15). As shmrn in reference 6, the fuselage shape has a very defi.

30、ni.teeffect on the influence of the fuselage on the tail contributionto c%“CONCLUSIONS .Analysis of the results of an investigationto determine the effect tof wing aspect ratios 2, 4, and 6 on the static longitudinal and staticlateral stability characteristicsof a series of 45 sweptback-midwingmodel

31、s through an angle-of-attackrange from.-4.to 32 leads to thefollowing conclusions:1. The tail effectiveness in producing negative pitching momentincreased with an increase in wing aspect ratio and angle of attack andbecame approximately equal to the wing-off value at very high angles ofattack.Provid

32、ed by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-N/KM TN 4077 112. All complete models tested became directionally unstable in thehigh angle-of-attackrange primarily because of sm increasing loss inthe stable contribution of the tail both with angle of atta

33、ck andincreasingwing aspect ratio and,.also, because of the unstable contri-bution of the wing-fuselage ccmibination.Langley Aeronautical Laboratory,National Advisory Comittee for AeronauticsLangley Field, Vs., Jfie 4, 1957.Provided by IHSNot for ResaleNo reproduction or networking permitted without

34、 license from IHS-,-,-12 NACATNk077.1. Campbell, John P., and McKhney, MarionCalculating Dynamic Lateral Stabilitymating Lateral StabilityDerivatives.(SupersedesNACA TN 2409.)2. Wolhart, Walter D., andand Lateral StabilityMidwing Models HavingNACATN 3649, 1956.3. Goodman, Alex: EffectsOS, David F.o

35、.: Summary of Methods forand Response and for Esti-NACA Rep. 1098, 1952., Jr.: Static LongitudinalCharacteristicsat Low Speed of Unswept-Wings With an Aspect Ratio of 2, 4, or 6.of Wing Position and Horizontal-TailPositionon the Static Stability Characteristics of Models With Unswept and45 Sweptback

36、 Surfaces With Some Reference to Mutual Interference.NACA TN 2x4, 1951.4. Queijo, M. J., and Wolhart, Walter D.: Experimental Investigation ofthe Effect of Vertical.llailSize and Lenh and of Fuselage Shapeand Length on the Static Lateral Stability Characteristicsof aMmlel With 45 SweptbackWing and T

37、ail Surfaces. NACA Rep. 1049,1951. (SupersedesWCATN 2168.)5. Liechtenstein,Jacob H.: Experimental Determination of the Effect ofHorizontal-Tail Size, Tail Length, and Vertical Location on Low-Speed Static Longitudinal Stability and Damping in Pitch of a Model .Having 45 SweptbackWing and Tail Surfac

38、es. NACA Rep. 1096, 1952.(SupersedesNACATNS 2381 and 2382.) w6. Letko, William, and Williams, James L.: Experimental Investigationat Low Speed of Effects of Fuselage Cross Section on Static Longi-tudinal and Lateral Stability Chuacteristics of Models Having 0and 45 Sweptback Surfaces. NACATN 3551, 1

39、955.7. Toll, Thomas A., and Queijo, M. J.: Approximate Relations and Chartsfor Low-Speed Stability Derivatives of Swept Wings. NACA TN 1581,1948.8. QueiSo, M. J., and Riley, Donald R.: Calculated Subsonic Span Loadsand Resulting StabilityDerivatives of Unswept and 45 SweptbackTail Surfaces in Sidesl

40、ip and in Steady Roll. NACATN 3245, 1954.9. Shortal, Joseph A., and Maggin, Bernard: Effect of Sweepback andAspect Ratio on Longitudinal Stability Characteristicsof Wings atLow Speeds. NACATN 1093, 1946.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,

41、-NACA TN 4077 1310. Hopkins, Edward J.: Lift, Pitching Moment, and Span Load Character-istics of Wings at Low Speed As Affected by Variations of Sweepand Aspect Ratio. NACATN 2284, 1951.11. Salmi, Reino J., and Carros, Robert J.: Longitudinal Characteristicsof Two 47.7 SweptbackWings With Aspect Rat

42、ios of 5.1 and 6.o atReynolds Numbers Up to 10 x 106. NACARML04, 1950.12. Salmi, Reino J., and Fitzpatrick, James E.: Yaw Characteristics andSidewash Angles of a 420 Sweptback Circular-ArcWing With a Fuse-lage and With Leading-Edge and Split Flaps at a Reynolds nuaiberof 5,300,C00. NACARML7130, 1947

43、.13. Neely, Robert H., and Conner, D. William: Aerodynamic Character-istics of a 420 Swept-Back Wing With Aspect Ratio k andNACA 641-112 Airfoil Sections at Reynolds Numbers l%rorn1,700,000to 9,500,CX30. NACARML7D14, 1947.14. Silverstein,Abe, and White, James A.: Wind-Tunnel InterferenceWithParticul

44、ar Reference to Off-Center Positions of the Wing and to theDownwash at the Tail. NACA Rep. X7, 1936.15. Giis, Clarence L., Polharm.m,Edward C., and Gray, Joseph L., Jr.:Chsrts for Determining Jet-Ikmdary Corrections for Complete Modelsin 7- by 10-Foot Closed Rectangular Wind Tunnels. NACA WR L-123,1

45、945. (FormerlyNACAARRL31. )Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA TN 4077TABLEI.- GEOMWRICFuselage:Length,ft . . . . . . . . . . .Finesaratio . . . . . . . . . .CHARACTERISTICS. . . . . . . . . . . . . . .OF MODELS. . . . . . . . . . .

46、. . . . . .Mountingpoint,distancemeasuredfromnose of fuselagepsxallelto flmelagereferenceline,ft . . . . . . . . . . . . . . . . .Diameterat?5/40f tail group,f% . . . . . . . . . . . . . . . .Verticalttil:Aspectratio . . . . . . . . . . . . . . . . . . . . . . . . . . .Sweepangleofquarter-chordline,

47、deg. . . . . . . . . . . . . .Taper ratio . . . . . . . . . . . . . . . . . . . . . . . . . . .Spsm,ft . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Root chord,ft. . . . . . . . . . . . . . . . . . . .Tipchord, ft. . . . . . . . . . . . . . . . . . . .Meanaerodynamicchord,5v, ft . . . . .

48、 . . . . . . . . . . . . .?V, ft. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Zv,ft. . . . . . . . . . . . . . . . a71 . . . . . . . . . . . . .krearatio, j . . . . . . . . . . . . . . . . . . . . . . . .NACA airfoilsectionin planesNrallel to fuselagecenterlineHorizontaltail:Aspectratio .SweepangleofTaperratio .span, ft . . .Root ChOld, ftTip chord,ft. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .qyarter-chordline,deg. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .