1、NATIONAL ADVISORY COMMITTEEFOR AERONAUTICS i_l_._ _SREPORT No. 666WIND-TUNNEL INVESTIGATION OF N. A. C. A, 23012,23021, AND 23030 AIRFOILS WITH VARIOUSSIZES OF SPLIT FLAPBy CARL J. WENZINGER and THOMAS A. HARRIS_EPR DUCED8Y_ONAL TECHNICALN,_ “-N SERVICEINFORhAA Ii_RT_ENT oF COMMERCEU S DEP.A. VA 221
2、61SpR|_GFtE_D, “Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-AERONAUTIC SYMBOLS1. FUNDAMENTAL AND DERIVE D UNITSLength Time Force Power .Speed .SymbolltFMetricPVUnit Abbrevia-tionmeter msecond . sweight of 1 kilogram . kghorsepower (metric) .kilom
3、eters per hour k.p.h.meters per second . m.p.s.EnglishUnitfoot (or mile) second (or hour) .weight of 1 pound .horsepower miles per hour feet per second Abbrevia-tionft. (or mi.)see. (or hr.)lb.hp.m.p.h.f.p.s.w,g,m,L2. GENERAL SYMBOLSWeight-ragStandard acceleration of gravity-9.80665m/s2 or 32.1740 f
4、t./sec. 2WMass-_-gMoment of inertia-ink 2. (Indicate axis ofradius of gyration k by proper subscript.)Coefficient of viscosityv, Kinematic viscosityp, Density (mass per unit volume)Standard density of dry air, 0.12497 kg-m4-s _ at15 C. and 760 ram; or 0.002378 lb.-ft. -4 sec. zSpecific weight of “st
5、andard“ air, 1.2255 kg/m 3 or0.07651 lb./cu, ft.3. AERODYNAMIC SYMBOLSS, AreaS_, Area of wingG, Gapb, Spanc, Chordb2_, Aspect ratioV, True air speed1q, Dynamic pressure_-_pVL, Lift, absolute coefficient CL_-a_D, Drag, absolute coefficient CD=_Do, Profile drag, absolute coefficient CD0-a_D_, Induced
6、drag, absolute coefficient Cm=a_Dp, Parasite drag, absolute coefficient CDv-a_J-C, Cross-wind force, absolute coefficient Cv=_R, Resultant force_t,Q,VlI.tC_,5,0_02O_tt,at , Angle of setting of wings (relative to thrustline)Angle of stabilizer setting (relative to thrustline)Resultant momentResultant
7、 angular velocityReynolds Number, where 1 is a linear dimension(e.g., forL a-model airfoil 3 in. chord, 100m.p.h, normal pressure at 15 C., the cor-responding number is 234,000; or for a modelof l0 cm chord, 40 m.p.s., the correspondingnumber is 274,000)Center-of-pressure coefficient (ratio of dista
8、nceof c.p. from leading edge to chord length)Angle of attackAngle of downwashAngle of attack, infinite aspect ratioAngle of attack, inducedAngle of attack, absolute (measured from zero-lift position)Flight-path angleProvided by IHSNot for ResaleNo reproduction or networking permitted without license
9、 from IHS-,-,-REPORT No. 668WIND-TUNNEL INVESTIGATION OF N. A. C. A. 23012,23021, AND 23030 AIRFOILS WITH VARIOUSSIZES OF SPLIT FLAPBy CARL J. WENZINGER and THOMAS A. HARRISLangley Memorial Aeronautical Laboratory161568-39-IProvided by IHSNot for ResaleNo reproduction or networking permitted without
10、 license from IHS-,-,-NATIONAL ADVISORY COMMITTEE FOR AERONAUTICSHEADQUARTERS, NAVY BUILDING, WASHINGTON, D. C.LABORATORIES, LANGLEY FIELD. VA.Created bY act of Congress approved March 3, 1915, for the supervision and direction of the scientific study of the problems offlight (U. S. Code, Title 50,
11、Sec. 151). Its membership was increased to 15 by act approved March 2, 1929. The members areappointed by the President, and serve as such without compensation.JOSEPH S. AMES, Ph.D., Chairman,Baltimore, Md.V._NNEVAR BUSH, So. D., Vice C_irman,Washington, D. (_.CHARLES G. ABBOT, So. D.,Secretary, Smit
12、hsonian Institution.HENRY H. ARNOW, Major General, United States Army,Chief of Air Corps, War Department.ROBERT H. HINCKLEY, A. B.,Chairman, Civil Aeronautics Authority.JEROME C. HUNSAKER, Sc. D.,Cambridge, Mass,SYDNEY M. Kl_us, Captain, United States Navy,Bureau of Aeronautics, Navy Department.CHAR
13、LES A. LINDBERGH, LL. D.,New York City.F_cm W. REICHELDERFER, A. S.,GEORGE H. BRZTr, Brigadier General, United States Army,Chief Matdriel Division, Air Corps, Wright Field, Dayton,Ohio.LYMAN Jo BRIGGS, Ph.D.,Director, National Bureau of Standards.CLINTON M. HESTER, A. B., LL.B.,Administrator, Civil
14、Aeronautics Authority.Chief, United States Weather Bureau.Jos_r H. TowEP.% Rear Admiral, United States Navy,Chief, Bureau of Aeronautics, Navy Department.EDWARD WARNER, SCo D.,Greenwich, Conn.ORVXLLZ WRmHT, So. D.,Dayton, Ohio.GEORGE W. LEwis, D/rector of Aeronautical ResearchJoss F. VICTORY, Sectar
15、yHENRY J. E. REID, Enoineeri_l_Charge , Langley Memorial Aeronau$ical Laboratory, Langley Field, Va.JosN J. InE, Technical Assistant in Europe, Paris, FranceAERODYNAMICSPOWER PLANTS FOR AIRCRAFTAIRCRAFT MATERIALSLANGLEY MEMORIAL AERONAUTICAL LABORATORYLANGLEY FIELD. VA.Unified conduct, for all agenc
16、ies, of scientific research on thefundamental problems of flight.5-24-39TECHNICAL COMMITTEESAIRCRAFT STRUCTURESAIRCRAFT ACCIDENTS INVENTIONS AND DESIGNSCoordination of Research Needs of Military and Civil AviationPreparation of Research ProgramsAllocation of ProblemsPrevention of DuplicationConsider
17、ation of InventionsOFFICE OF AERONAUTICAL INTELLIGENCEWASHINGTON, Do C.Collection, classification, compilation, and dissemination ofscientific and technical information on aeronautics.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-REPORT No. 668WIND
18、-TUNNEL INVESTIGATION OF N. A. C. A. 23012, 23021, AND 23030 AIRFOILS WITH VARIOUS SIZES OF SPLIT FLAPBy CARL J. W_NZING_R and THOMAS A. HARRISSUMMARY 230 series were used because they appear to be generallyAn investigation has been made in the N. A. C. A. satisfactory for most purposes. The high-li
19、ft device7- by lO-Joot wind tunnel off large-chord N. A. C. ,4. investigated with the airfoils of various thicknesses$8012,23021, and 23030 a_rfoils with split flaps 10, 20, 30, was the simple split flap, which is used as a basis of corn-and 50 percent oj the wing chord to determine the section pari
20、son with other high-lift devices. Flaps ranging inchord from 10 to 40 percent of the wing chord wereaerodynamic characteristics oJ the airfails as affected by each airfoil. These tests are expected to beairfoil thickness, flap chord, and flap deled_on. The tested oncomplete section aerodynamic chara
21、cteristics o all the foUowed at a later date with tests of slotted flaps oncombinations tested are g_ven in the form o.f graphs o lift, similar airfoils. MODELSdrag, and _itching-moment coe_cients, and certain pLAINAIRFOILSapplications to aerodynamic design are discussed.The final maximum lift coe_v
22、ients.for Zhe three airfoils Three basic wings, or plain airfoils, were used in thesetested with the 020c_ flap were about equal. For the tests; each had a chord of 3 feet and a span of 7 feet.airfoils with the 0.10cw flap, She ma_dmum lift coe_w icnt The models were constructed of laminated wood an
23、ddecreased with airfoil thickness; .for the airfails with the were built to the N. A. C. A. 23012, 23021, and 230300.30cw or O.$Oc,r flaps, the mozimum l_fl eoe_cient _n- profiles. The thickness of each of these airfoils is,creased with a_rfoil thickness to a maximum“ vaI_ o.f respectively, 12, 21,
24、and 30 percent of the wing chord,_.95. WitMn the range covered, the increment o.f mazimum c,o. The ordinates for each of the three airfoils arelift coc_dent due to the split flaps was practically inde, listed in table I. The N. A. C. A. 23012 airfoil, whichpendent o Reynolds Number. The increase in
25、minimum had been previously used for the investigation de-profile-drag coe_wient with a_rfog thickness was large, scribed in reference 1, was already available.being about twice as great.for the N. A. C. A. 23030 as for FLAPSthe _3012 plain a_rfoil. Four simple split flaps extending along the entire
26、INTRODUCTION span were used with each model. The flap chords,or, were 0.10cw, 0.20c_, 0.30c_, and 0.40c_ and wereThe National Advisory Committee for Aeronautics is believed likely to cover the range of sizes that mightundertaking an extensive investigation of various high- be used in practice. (See
27、figs. 1, 2, and 3.) Thelift arrangements to furnish information applicable to flaps were built of plywood braced at several pointsthe design of wing combinations for the improvement of along the span and were arranged for setting at de-the safety and the performance of airplanes. Thus far, flections
28、 from 0 to 105 down. The flap deflection,most of the tests have been made with wings having a St, is measured between the lower surface of each air-thickness 12 percent of the wing chord and having the foil and .the flap, as shown in figures 1, 2, and 3.Clark Y or the N. k. C. A. 23012 profile. It a
29、ppears TFSTSvery desirable at the present time, however, to extendthe investigation to include wings having other thick- The models were mounted in the closed test sectionnesses and also other airfoil profiles. Tim present report of the N. A. C. A. 7- by 10-foot wind tunnel so as todescribes the res
30、ults obtahmd from tests in the 7- by span the jet completely except for snmil clearances at10-foot wind tunnel of airfoils of various thicknesses each end. (See references 1 and 2.) The main air-equipped with high-lift devices, foil was rigidly attached to the balance frame byThe investigation was m
31、ade of airfoils having thick- torque tubes, which extended through the upper andnesses from 12 to 30 percent of the wing chord; these the lower boundaries of the tunnel. The angle ofthicknesses are believed to cover the range likely to be attack of the model was set from outside the tunnel bymet wit
32、h in practice. Airfoil sections of the N. A. C.A. rotating the torque tubes with a calibrated electric1Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- REPORT NO. 668-NATIONAL ADVISORY COMMITTEE FOR AERONAUTICSdrive. Approximately two-dimensional flo
33、w is ob-tained with this type of installation and the sectioncharacteristics of the model under test can be deter-mined.A dynamic pressure of 16.37 pounds per square footwas maintained for most of the tests, which cor-responds to a velocity of 80 miles per hour under stand-ard atmospheric conditions
34、 and to an average testReynolds Number of about 2,190,000. Because of theFIGURE L-Sectlon of N. A. C. A. 23012 airfoil with split flaps, e;=O.10cw. O.20cw.0.30c, and 0.40c,.cw=36.Ft(ltrlll 2.-Section of N. A. C. A. 23021 atrfofl with split flaps, e/-0.10c, 0.2_,0.30c., and. OAOcc_=36“,Fl_ua_ 3.-Sect
35、ion of N. A. C. A. 23(30 airfoil with split flaps, c/=0.10c, 0.20=,0.30e., and 0.40eturbulence in the wind tunnel, the effective ReynoldsNumber, R, was approximately 3,500,000. For alltests, R6 is based on the chord of the airfoil with theflap retracted and on a turbulence factor of 1.6 for thetunne
36、l.Each airfoil was tested by itself without the flap sothat the characteristics of the plain airfoils could bedetermined. Each of the four split flaps was thentested on each of the three airfoils and deflected in 10 or 15 increments up to the deflection giving thehighest value of the maximmn lift co
37、efficient.An angle-of-attack range from -6 to the angle ofattack for maximum lift was covered in 2 incrementsfor each test. Lift, drag, and pitching moment weremeasured at each angle of attack.RESULTS AND DISCUSSIONCOEFFICIENTSAll test results are given in standard section non-dimensional coefficien
38、t form for the airfoil and flapcombinations corrected as explained in reference 1./60 .8 .4 .6 .6 1.0 1.2 1.4 I.Bu_ Sec/ion lift coefficienf, c zFIoUx 4.-Section aerodynamic characteristics of N. A. C A. 23012 plain airfoil.el, section lift coefficient, l/qc=.cdo, section profile-drag coefficient, d
39、o/_c,_.c_.,.)o, section pitching-moment coefficient about aero-dynamic center of plain airfoil, m_._.)o/qC_ 2.where1do,_(a.c.)O,_1,Cto,anda0is section lift.section profile drag.section pitching moment.dynamic pressure, 1/2 pV2.chord of basic airfoil with flap fully retracted.is angle of attack for i
40、nfinite aspect ratio.flap deflection.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-N. A. C. A. 23012, 23021, AND 23030 AIRFOILS WITH SPLIT FLAPSPRECISIONThe accuracy of the various measurements in thetests is believed to be within the following lim
41、its:-t-0.0006_o . 4-0“1 Cd(c_-l.0)0.002c_,._ . +0.03 ceoccz.2.5) .+0.003 _t . +0“2Cm(a.c.) 0 .e_o_ -t-0.0003SECTION AERODYNAMIC CHARACTERISTICSPlain airfoils.-The section aerodynamic characteris-tics of the N. A. C. A. 23012 plain airfoil, as determinedwith the two-dimensional-flow installation, are
42、 shownI.048.044_ .008.004_.b . O _ 0 .2 .4 .6 .8 LO 1.2 1.4 1.8FI_URE it is 11 percent of thechord ahead of the quarter-chord point of the wingand about 44 percent of the chord above the chordline.in figure 4. Similar results for the N. A. C. A. 23021and the N. A. C. A. 23030 plain airfoils are give
43、n infigures 5 and 6, respectively. The data for the N. A.C. A. 23012 and 23021 airfoils are discussed in references1 and 3, respectively, and therefore require no furtherdiscussion. The data for the N. A. C A. 23030 airfoil,however, depart from the results of the thinner sectionsin several respects.
44、 The slope of the lift curve is only0.068 as compared with about 0.105 for the N. A. C. A.23012, although there is a marked increase in slope atangles of attack above 2 The angle of attack forzero lift, however, is the same as for the N. A. C. A.23012 and 23021 airfoils. The relatively flat-top lift
45、curve given by the N. A. C. A. 23030 airfoil is probablytypical of very tt_ick airfoils. Its pitctmlg-momeIlt Fl(_uR_7.-Etleetoftbicknessofplainairfilsnmaximumliltandminimumdrag“i; !:.I I I I I I I I I I_- .012_._, _ _, k_n ,._z 28 32 PA/rfoil th/ckne_s, percent cjSZA C.A. 230,ser s) %Provided by IH
46、SNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-REPORT NO. 668_NATIONAL ADVISORY COMMIFrEE FOR AERONAUTICS:“uultE 8.-Sectiou aerodynamic characteristics of N. har-acteristies of the N. A. C. A. 23012 airfoil with the0.10c_, the 0.20c_, the 0.30e_, and the 0.40cw s
47、plitflaps are shown in figure 8. All these data wereobtained at an effective Reynold_ Number of 3,500,000,except as noted on the figure. The lift curves haveabout the same slopes as they did for the plain airfoils.The angle of attack for maximum lift decreases fromtions will more than overbalance th
48、is drag increase inapplication to a given design. In other words, theprobability should not be overlooked of actuallyobtaining desired characteristics with the tlfick sectionsbecause of the possibility of housing parts of tileairplane entirely within the wing, which would beiinpussible with the tt_m
49、er sections./.2 1.6 20 2.4 2.8 _4 0 .4 .8 /2 /.6 20 2.4 2_cect/on I/ft coefficient, ct(a) The 0.10c, split flap. (b) The 0.20c, split flap.(c) The 0.30, split flap. (d) The 0.40e, split flap.FI(;URg ll.-Comparison of profile-drag coefficients for airfoils with split flapsabout 15 with the flap neutral to ab
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