1、., ,., , . . . . . . . . . . MR Jan. 10L4 MAR i -NATIONAL ADWSORY COMMlWE FOR AERONAUTICSWAinmm lUIPOIU!ORIGINALLY ISSUEDJanuazy 1943 aaMemorandum ReportTESTS OF TWO MODEIS REPRESENTING INTERMEDIATEINBOARDAND OUTBOARD WING SECTIONS OF THE XB-36AIRPLANEBy Seymour M. BogdonoffLangley Memorial Aeronaut
2、icalLaboratoryLangley Field, Va.“NAcA”:-:WASHINGTON $1 7.,NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution ofadvance research results to an authorized group requiring them for the war effort. They were pre-viously held under a security status but are now un
3、classified. Some of these reports were not tech-nically edited. All have been reproduced without change in order to expedite general distribution.IL 662Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Imllliuiliiiillllllllll31176Olaa 6466 n MEMORANDUM
4、 REPORTfor the. . . . ArmyAir Forces,.Materiel Co-rid .TESTS OF TWO MODELS REPRESENT IN(3INTERMEDIATE INBOARDm OUTBOARD -mm S3CTIOMSOF THE XB-36 AIRPLANEBy Seymour M. Bogdonoff.-At the requst oftests were made In theIRODUOTION .the Army Atr Forces, Materiel “Command,two-dimensional low-turbulence pr
5、es-sure tunnel and the two-dimensional low-turbulence tunnel oftwo nmdels submitted by the Consolidated Aircraft Corporation.,.The model representing the inboard saction was testedwith four combinations of flap shape and slot entry to obtaintho best slotted flap characteristics on the basis of maxi-
6、 .mum section lift coofflcient and minimum section drag coef-ficient when retracted. The combination chosen was t.entested to datermtne the effect of varying the gap with flapin the maximum lift position. Tests on this section in-cluded lift, drag, nressure-distribution measurements, andpitching mom
7、ents for various flap deflections 8f. A scale-effect test was made on the section with flap retracted andat maximum lift position.Tests on the nmdel representing the outboard seotion,., ., an airfoil with an Internally balhced aileron and balancedsplit flap,.included lift, pressure-distribution meas
8、urements,and pitching moments with various aileron deflections oa for.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-, , . . . . . - . .-. -, - -, , - a73 a15 a15 a15 a14a14a14a14a14a14a14a14a14 a15-2-eaoh flap deflection. Drag and scale-effect data
9、 were ob- ctained for the flap-retracted and neutral-aileron condition.Aileron effectiveness was also Included.lostof the data were obtained at a Reynolds number Rofapproximately 8,000,000 and 9,000,000 with the exceptionof the pitching-moment data obtained on the-moment balance.These tests were run
10、 at a Reynolds number of approximately2,000,000, The large number of presse-distributiondiagrams obtained =e not presented in this report but are. .available, . .lhODINXThe models were of 2056cZ=10where Cz=lo is the section lift coefficient at an angleof attack of 1.The section lift coefficients for
11、the outboard wing .section should be corrected by the equationCt(oorrected) = 0.965cZ + 0N37cz=10Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. -4-The section pitching-moment coefficients presented forthe outboard section were obtshed from a.momen
12、t balanceusing a calibrated torque rod, RIemodel was pivoted atthe qunter-chord point and there was a gap of approxtiately0.15 inch between the model ends and the tunnel walls toallow ree movement of the model. All tests or this typewere made at a Reynolds number of approxtiately 2,000,000.For the i
13、nboard section, pitching moments were ob- tained by the above method for flap deflections of 0 and200 For a flap deflection of 4.0,however, whore sectionpitching moments were above those for which the balance wasdesied and oscillationswere large, moments werecalculated by graphloal means from pressu
14、re-distributiondata obtained at a Reynolds number of approximately 8,000,000.These calculations vererepeatb.dfor a flap deflection of 20to check the data obtained rom the moment balance and togive an indication of possible scale eifeeton aectlonpitching-moment coefficient. ThQ graphical method usedg
15、ives the total section pitching-moment coefficient and in-cludes the component of moment associated with the chordforce.RESULTS AIJDDISCUSSIONInboard sectio.- The Inboard section model with aslotted ilapwas equipped to be tested with four combinationsProvided by IHSNot for ResaleNo reproduction or n
16、etworking permitted without license from IHS-,-,-“5-,./.of flaf5shape and slot entry (fig. l). The lift data ob-. ,. .,. . -.talned using the smallest flap gap, A-AI, are presented in.figures2 to 5 and the curve ofsection drag Coeffiotent ad “against seotion lift coefficient Cz- for flap retracted i
17、spresented In figure 6. Some trouble was exparlenced ingetting”acwu?ate drag measurements beoause of spanwise flowih the slot, although all drag tests were made with thincardbotid dams glumd in the slot. Also included in .figure 6 are the results of a test using flp 2 and nose 2with the gap filled w
18、ith modelin clay.No combination of flap and nose gives any particularlylarge advantage over any of the other combinations, butflap 1 and nose 1 teem to be the most favorable combinationsince it has the highest ?naxlmtm lift coefficient, 3s10, witha smooth lift curve, and sliltly lo-uery be considere
19、d negligible below maximum lift in the rangetested.Outboard section.- For the outboard section model withthe internally balanced aileron and balanced split-flap(fig. 12)lift data were obtained for six poaltions of flapthrough a range of aileron deflections (figs. 13 to 18)For the flap retracted and
20、fully deflected, 50, lift datawere obtained for aileron deflections of frcm 20 to -20 inProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I . . . . .-. 5 increments. For the300, lift- data-20 defleotionsof the-7-Intermediatepositions, 10, 20, -.Were ob
21、tained only at 20, 0, andaileron, The maximum seotion W%ooefficlentobtained for neutral aileron was 2,.57for 50 “?,deflection. The.ke-”llerondeflections, The maximum .lit coelYiclente for flap deflections of 20 and 30 are”higher for -200 defle:dtionof the aileron than for 0 or 20.A negative defleotl
22、on of the aileron probably induces alower pressure behind the flap causi larger and better “. flow through the sap marve for 0 flapJ:deCL4n*-. . tion (position 5) ” AC+/A8cl=OP,0)y.bp-taken as a,:. .),-.,:!*. . %“. : . . . . . . . . . . . “-” . .“: .”-. . . . . . .a.,.1.Provided by IHSNot for Resale
23、No reproduction or networking permitted without license from IHS-,-,-.measure of aileron-effectiveness,although the airpl does,. . .not aotuallyfly In this.oondltion. This factor Aa/Aequals 0.34 for the flap retraoted and failsIn the normalaileron-effactivenessrange. l?wom figure 13 It may be seenth
24、at this faotor stays constant to high section lift coef-ficients. For the flap fully extended to 50, Aa/Ai5dropsto 0.26 whioh Is below the nozmal range and gives only76.5 percent o +he-”;: “- ,.For the inteimediateiflap deflections; positions , 3, “and 4.,aileron“effectivenessdrops to a critical poi
25、nt, as low as 37 pekt “ofnormal effectiveness for poaitlon“4in”“the high llft condition. For these three positions the “average Aafi:./.,-.,.” - . . . . .“ ! . . J,. . . ,.,. . . . . . . . . . .“.” . IProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.
26、 ;“. . .1 .fap. . . -1 “ . .“ ”. . . ,. .-9 -” “ “ . . ,.c, . . .The variation ok rnaktiumsection lift cotiffkc1.entfor-. .,:“retracted.an-dlly”d.le”bted,-5-OOJforchange. .!.Reynolds number Is presented in f.zres 19 arid20.”flap retracted, the maximum lift coefflctant variescinForfrom1.28 to 1.47 fo
27、r a change”ZnlRqnolds number”of”from2,000,000 to 8,000,000;“for50 deflection of the lap, themaxtium lift coe”fficlentvuiqs from 2.1+0to 2.68 for thesame change.in Reynolds number, figure 21”ls”presented the curve of section dragcoefficient against section lift coefflclentfor the flap-retracted and a
28、ileron-neutralcondition.Section pitching-momentdata for ill flap deflections, thrm28 was oB-talned with the lmagest flap gap.”tested.C-$?, at a lap,”defleo.tiortP140. This compares very well with other “.”tests of similar flaps. . s . ,:., .,. On the basis of the tests made, the need.:of doorto clos
29、e the slot when the flap is retracted in some.con-fiogmrations is not.definitely.indica-ted, . “.1Outbomd Section “ . . “.4. The maximum section llft.coefficientobtained was2.59 for 50.deflection of the flap and 5.deflection ofthe aileron. 5. Some account must be taken”of the incrase in :maximum sec
30、tion liftcoefficient-forneative a$lerm de-flections for inter?rgdj.nteflap positions 2, 3, and.4.s6. Aileron ei-iactivenessis deficient for the inter-mediate flap positions end falls slightly I391ow the raneusuall consiered acceptable for-the fully detlccted . .position, The eifectivonessof the aile
31、ron alone, flapretracted, is satisfactory,Langley ?temorialmonmtlcl Laboratory,National l.tvioryCo?rrdttceTTGTAct”onautics,Langley Field, Vs., Janua.z-y7, 1943.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-+ -Pivot pointNATIONAL ADVISORYCOMMITTEE F
32、OR AERONAUTICSFigure 1.- Comblnatlon of flap and clot entry for inboard wing a71ectlonmodel ot x2-36 airplane with Blotted flap.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted witho
33、ut license from IHS-,-,-IProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted without li
34、cense from IHS-,-,- - - Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-gum 8.- Three positionsof slotted flap on inboard wing secthn modelof XB-36Rirph
35、ne used to test effect of Varfing gap size. map 1,slot entry 1S 6f, 40.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IProvided by IHSNot for ResaleNo
36、reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Maximum negativedeflection,/Chordline. . deflection,1 002, 103, 204, 305, 40 Jaileron-200aileron2006, 50 NATIONAL ADVISORYCOMMITJEE FOR
37、AERONAUIIC$”figure12.- Ponitiom of balanced apllt flap and amungement of titernallbalmea71iler.oaoaoutboardwing6eclenmodelof XW3A ainlmna.-. =-Provided by IHS Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking
38、 permitted without license from IHS-,-,-. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.Provided by IHSNot for ResaleNo reproduction or networking pe
39、rmitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I - -Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
