1、Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-_:_._._,_._-_,_,_.:_. , !_i,_ _-_t_;_:_,_;_._, _._,_._“_._,_ _,_i_ .!_.“-_._:_, _.“.;“_._“ -_:_ _._ _._“ ,_“_i_ ,_:_._!:_,._:_,._?i_“(:_,_ _. _,._ NASA _,i._ TechnicalPaperi. 2382:,i 1985I_ Wind-Tunnel
2、Investigation ofi- a FuU-Scale Canard-Configured_General Aviation Airplane_. Long P. YipLangley Research CenterHampto n, Virginia4N/ANahonal Aeronauhcsand Space AdministrationScientific and TechnicalInformation BranchProvided by IHSNot for ResaleNo reproduction or networking permitted without licens
3、e from IHS-,-,-i_ Summary Introduction_“ As part Of the aeronautics program in the areaI An investigationwas conductedintheLangley30- ofstall/spinresearchattheLangleyResearchCen_r, by60-1t0otTunneltodeterminetheaerodynamicchar- wind-tunneltestswereconductedtoassessand _ocu-i acteristicsofa powered,f
4、ull-scalemodel ofa general ment theaerOdynamiccharacteristicsofa canardcon-aviationairplaneemployinga canard.Althoughpri_ figurationdesignedforgeneralaviationuse.Inthemid-mary emphasisoftheinvestigationwaS placedon eval- 1970s,a new homebuiltairplanedesign,theV_riEzeuatingthe aerodynamicperformancea
5、nd the stabil-i. . ityand controlcharacteristicsof thebasicconfigura- (ref.I),made asignificantimpacton thegeneralavia-tioncommunitybecauseOfitscanarddesignand otheri_ tion,testswere alsoconductedto studythe foliow_ advancedfeatures.Theseadvancedfeaturesincludedingeffectsofvaryingthebasicconfigurati
6、on:effectofReynoldsnumber;effectofcanard;effectofoutboard useofcompositeconstructionforlighterweightand for wingleading-edgedroop;effectofcenter-of-gravityIo- smoothersurfacecontourstoimproveaerodynamicper-formance,useofwingletson themain wing fordirec-i Cation; effeCt of elevator trim; effect of la
7、nding gear;effect of lateral-d:rectional controls; effect of power; el- tional stability and, at the same time, for reducing drag,Ii fectoffixedtransition;effectofwaterspray;effectsof and useofa canardsurfacetoincreasepitchstabilitynearstallsothatthemaximum trimangleofattackwas: canardincidence,cana
8、rdairfoilsection,and canardpo- lessthanwingstallangleofattack.sition;and effectsofwingletsand Upper wingletsize.Thisreportpresentsresultsofa full-scaleresearchAdditionalaspectsofthestudyweretodeterminetheboundary-layertransitioncharacteristicsoftheairfoil modeloftheVariEzedesigntestedintheLangley30-
9、.byi 60-FootTunnelforwhichpreliminaryresultswerere-. surfacesand theeffectoffixing theboundarylayertobe turbulentby means ofa transitionstripnearthe portedinreference2.Testdataobtainedincludedmea-_ surementsofaerodynamicforcesandmoments oftheto-i leadingedge. The testswereconductedatReynoldsnumbers
10、from0.60 i0e to2.25x I0_,basedo the. talconfiguration,isolatedloadson thecanard,pressurewing mean aerodynamic chord, at angles of attack from. distributions, propeller torque-thruSt loads, and flow vi- !i sUalizationusingtuftsandsublimatingchemicals.Also- _.i -4.5to41.5,and atanglesof.sideslipfrom-1
11、5 to includedinthestudywereeffectofReynoldsnumber;i 15% effectofcanard;effectofoutboardwing leading-edge.The investigation indicated that employing the ca- droop; effect of center-of-gravity location; effect of el-n_.rd on this configuration was effective in providing in- evator trim; effect of land
12、ing gear; effect of lateral-.creasedstalldepartureresistancebecausethecanard, directionalcontrols;effectof power;effectoffixedtran-stalledbeforethe.wingstalled.Influenceofthecanard sition;effectofwaterspray;effectsofcanardincidence,flow field on the wing decreased the inboard loading canard airfoil
13、section, and canard position; and effects _.ofthewing as theoutboardloadingofthewing in- ofwingletsand upperwingletsize.creased.The increasedoutboardloadingand spanwiseflowdevelopmenton the wing causedwing tipstall. SymbolsThe additiOnofawingoutboardleading-edgedroopin-creasedstallangleofattackand i
14、ncreasedpitchstability Alllongitudinalforccsand moments arereferredtoat10wtomoderateanglesofattack.From testsusinga thewind axissystem,and alllateral-directi0nalforces-chemicalsublimationtechnique,thenaturalboundary- - and moments arereferredto the body axissystem._ layertransitionwas fOundtobe at55
15、 percentchord UnlessOtherwisenoted,total-airplaneand canardtoo-i: ofthecanard.Fixingtransitionneartheleadingedge mentsarepresentedwithrespecttoacenter-of-gravityofthecanardresultedina significantreductionoflift locationatfuselagestation99,whichwas0.71eaheadofdue toflowseparationnearthetrailingedgeof
16、theca_ theleadingedgeofthewingmean aerodynamicchord_,nardand,subsequently,a nose-downtrimchangeand and ataverticallocationon waterline16.Also,unless; loss of elevator effectiveness. Variations in the canard otherwise noted, total-airplane and canard aerodynamicairfoil showed that the canard airfoil-
17、section character- coefficients were reduced by using a wing reference areaistics can strongly affect the airplane stall and poststaU based on the trapezoidal planform of the wing projectedcharacteristics. Moving the canard to a lower position to the fuselage centerline.had little effect on the stat
18、ic longitudinal and lateral-d_rectmnal aerodynamic characteristics of this confign- . . b wing span, 22.17 ft_ ration. The lateral-directional stability was generally b_ upper winglet span, fti ! satisfactory, but the directional stability became weak_ at high angles of attack. Larger upper winglets
19、 pro- Co total airplane drag coefficienL-!, sided significant increases in directional stability of the .configuration. CD,d canarddragcoefficient,Canard balancedra|g, qS!Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-_ _ ?/_ _i_ :_ _i _ _i_/_ _!_ .
20、_ _ _:_ _i/_! _ _ _ _ _Y_!_2_?/_ _!_!i_ii_i!,_i_,_,;-_._,._,_:_.,._,-. . ,.,.t!III_“ CD,! skin-frlction drag coefficient, Skfn.frlct|ondraI NI exposed canard area, ft2q$i_ C_. total-airplane lift coefficient, _j_ V free, stream velocity, ft/secV/nd propeller advance ratio, V/(Propeller rotation_ CL,
21、c canard lift coefficient based on wing reference_. speed Propeller diameter)I area, canard b_l_n_ellft (CL in computer-q8generated figures) z chordwise distance from leading edge, ftI C_, c canard lift coefficient based on canard plan- (z/C)T boundary-layer transition locationI form area, Cbx_ardba
22、lance lift_S, _ spanwise distance from plane of symmetry, ft. I_: CL,_ lift coefficient at zero angle of attack y_ distance along winglet span, ft “!, CLo lift-curve slope, p:r degree (_ angle of attack relative to WL, deg/_ angle of sideslip, degC_ rolllng-moment coefficient, Roll_n_momentq8_. ACv
23、incremental drag coefficientf C_ rolling moment due to sideslip, per degreeAC_ incremental rolling-moment coefficientCm total-airplane pitching-moment coefficient, ACn incremental yawing-moment coefficienti. “ Pit_hin_ momentqse AC_ incremental side-force coefficientC._,c canard pitching-moment coef
24、ficient relative to_ airplane e.g., Canardbalancepltchin_ moment _ aileron deflection based on a setting of equal :_e and opposite deflection, positive when righti coefficient atzero of aileron is down, degC,_,o pitching-momentangleattack _ elevator deflection, positive trailing edgeCm. slope of pit
25、chimg-moment curve with respect down, degto angle of attack, per degree . _z rudder deflection based on setting one rudderCn yawing-moment coefficient, Yawin_moment in an outward deflection for dirertional _,“qSb control, positive left rudder deflected, deg _Cn_ yawing moment due to sideslip, per de
26、_ee _/ propeller efficiencyCv pressure coefficient, _ q Subscripts:CT thrust coefficient, _ c canardq_Cr total-airplane stale-force coefficient, _ l. lower surface _.|.! Cy# sideforceduetosideslip,p_r degree max maximum .c .localchord,ft u . uppersurface_ _ , reference wingmean aerodynamicchord, w w
27、inglet 2.58 ft Abbreviations:c_ section normal-force coefficient obtained from BL butt line, in.integration of pressure measurements c.g. center of gravityic incidence angle of canard relative to WL, FS fuselage station, in.positive trailing edge down, deg L.E. leadingedgeL/D _lift-dragratio WL wate
28、rline, in.p local static pressure, Ib/ft _p_ free-stream static pressure, Ib/ft _i Model Description and Test Apparatus_ q free-stream dynamic pressure, lb/ft _The configurationusedinthestudywas apoweredi l R Reynoldsnumber baaedone full-scalemodel ofan airplaneintendedforthehome-i S reference.wing
29、area, 53.60 ft2 built, market (ref. 1). The model was constructed ofProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-:_,_=,_ _.,_ “ _,_ “- i, _!_ i ,;_ _f_ ,:_ _i_ :_. “_;_ :,:?_ _:,“ _.,:_“_,_,_ _,_; _ _I_, _, _J_.)_. :6_:. _.:._) _,_ _ “_ ,_: ,_ _._
30、 _._F_r_ _ _ :_-_ “ _ _4:_:_,“ _,_ _,!(_,W_ ._“_ _“_l_. :_“_,_.P_:_._:_“,._.,_.,_“_ “ “: - “_ “ - _ -_ _ “!l,. foam covered with fiberglass and epoxy. Body putty the engine inlet and exit areas were sealed and faired was applied to the wing and canard to attain the de- for a no-flow-through conditio
31、n NO attempt was madeI sired airfoil-section contours Geometric. characteristics to Simulate the internal duct fiow due to a reciprocatingof the model are given in table I and shown in figure I. internal combustion engine.I A total of 322 pressure orifices were installed in the Overall aerodynamic f
32、orces and moments acting ,mwing, canard, and wingiet. The pressure orifice loca- the model Were measured on the external scale balan,:e tions are given in table II. Photographs showing the system of the Langley 30- by fl0-Foot “funnel. (Seei model installed in the Langley 30- by 60-Foot Tunnel ref.
33、6.) In addition, the model was instrumented withare presented in figures 2 and 3. internal strain,gange balances to measure isolated loads. , The basic model configuration is defined as follows: on the canard and the propeller an, _-with scannivalveOutbOard wing leading-edge transducers to measure t
34、b _. surface preszures. Small: “ droop off cotton tufts were used m conjunction with fhtorescentCenter of gravity located at FS 99 photography to provid., flow visualization of the ,._,_.Nose gear removed (See ref. 7.) Tufts were.used in flow visualization studiesMain wheel pants off to examine area
35、 _.of flow separation and other surfacefiow conditions at angles of attack up to complete wing _Propeller removed, spinner on stall. Initially, tufts were installed on the upper surfacesInlet faired, exit area sealedHigh canard position with of the wing, upper wingiet, and canard. However, the: ic =
36、 0 tufts on the canard resulted in premature transition ofi Canard with GU 25-5(11)8 the boundary layer; thus, there was a large decrement inthe lift performance of the canard. Therefore, canard_ airfoil section (ref. 3) tufts were not installed in later tests because of theirE Small upper and lower
37、 wingiets adverse effect on the flow patterns of the canard. AVariations to the basic configuration include the chemical sublimation technique (ref. 8) was used to following: provide information on the extent of laminar flow on! Adding a discontinuous outboard wing the canard, wing, and winglet.lead
38、ing-edge droopRemoving canard Test Conditions and Corrections.Moving center of gravity to forward andaft locations Test conditions included a range of _ from -4.5 _ to.Varying landing-gear arrangements 41.5 -and a range of _ from -15 to 15_. AerodynamicAdding power effects data were obtained at free
39、-stream tunnel velocities ofVarying canard incidence 26, 68, and 94 mph that correspond to Reynolds num-Changing canard airfoil section bers based on _ of 0.60 10e, 1.60 I0e, and 2.25 I0e,Changing from high canard position.to respectively. Most of the tests, however, were conductedlow canard positio
40、n . at a nominal free-stream velocity of 68 mph.Removing wingiets The model was tested upright and inverted to eval-i Increasing upper wingiet size uate the flow angularity and strut tare corrections. Anextensive wind-tunnel calibration was made prior toRange of control settings tested were 6e -= “2
41、0 to model installation to determine the horizontal buoy-24_, 6a = -20 _ to 20_, and 6r = -406 to 40_. Pitch ancy correction, and flow-field surveys ahead of thecontrol was obtained with elevator deflections at a fixed model were made in the manner of reference 9 to de- -canard incidence setting. Ca
42、nard incidences of -4 _, 0_, termine the flow-blockage correction. These correctionsand 4_ were tested A low canard position (fig. l(a) have been applied to the data. Jet-boundary correc-was also tested because of interest in improving pilot tions were made in accordance with the method of ref-visib
43、ility Since earlier studies (refs. 4 and 5) indicated erence 10. Since an electric motor, rather than a recip- -that the droop was effective in delaying tip stall, tests rocating engine, was used to power the model and nowere conducted with the leading-edge droop installed, attempt was made to simul
44、ate the interned duct flow,(See fig. l(d).) Upper wingiets with 50 percent more no corrections were made for cooling drag due to a re.area (figs. l(b) and l(c) were also tested, ciprocating engine. Powered tests were conducted with a 200-HP elec-i tric motor to turn a fixed, pitch, 4.83-ft.diameter,
45、 twc_ Presentation of Resultsbladed propeller. The propeller is a Hendrickson_.i H58G64 propeller designed for c!_mb. The majority of The test results are presented in figures 4 to 44,_ I the tests was conducted with the propeller removed, and which are grouped in the order of discussion as follows:
46、ttProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-_._/_ _ _ _i!_ _i_i_i_ i_i_ _i!ii_ _ _ _i_!_!Ii : Figure Longitudinal characteristics . 39EffectofReynoldsnumber 4 Lateral-directionalcharacteristics 40_.: Pressuredistributions 5 Effectofwinglets:i :
47、 Sectionnormal-forcedistributions 6 Dragcharacteristics 41Lateral-directionalstability. 42and 43I Effectoftheoutboardleading-edgedro0p: Pressuredistributionsatanglesofsideslip 44Flowvisualizationwithtufts 7and 8I“ Longitudinal DiscussionofResultscharacteristics 9Elevatortrimrequirements 10t- Charact
48、eristics 11 Effect of Reynolds NumberDragLateral-directional stability characteristics . . 12 In order to assess the sensitivity of the confignra.i Liftand pitching-momentcharacteristics: tiontoReynoldsnumbereffects,datawerecomparedatEffectofcanard 13 .Reynoldsnumbersbasedon _of0.60 I0s,1.60x 10e,Elevatorcontroldeflections 14 and 2.25x i0e.Thesedataareshown infigure4.TheEffectofcenter-of-gravitylocationon liftand pitching-momentcharacteristicsofthe basic elevatortrimrequirements 15 configurationand,also,theisolatedliftcharacteristicsofthecanardobtai
