1、NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS N A C 11 IK- “f REPORT No. 664 WIND-TUNNEL INVESTIGATION OF AN N. A. c. A. 23012 AIRFOIL WITH VARIOUS ARRANGEMENTS OF SLOTTED FLAPS By CARL J. WENZINGER and THOMAS A. HARRIS 1939 REPRODUCED BY NATIONAL TECHNICAL INFORMATION SERVICE u. S. DEPARTMENT OF COMM
2、ERCE SPRINQFlELD, VA. 22161 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-w, y, m, I, !J., S, Sw, G, b, C, b2 S V, q, L, D, 0, AERONAUTIC SYMBOLS L FUNDAMENTAL AND DERIVED UNITS Metric English Symbol nit Abbrevia-Unit Abbrevia-tion tioJl Lcngth _ l
3、 m eter _ m foot (or mile) _ _ ft . (or mi.) Time _ t second _ _ s second (or hour) _ _ _ sec. (or hr.) FOTce _ F weight of 1 kilogram _ kg weight of 1 pound _ _ lb. Power _ P horsepower (metTic) _ - - -hor epower _ _ hp. Speed _ _ V kilometers pCI hour. _ k.p.h. miles per houL _ _ m.p.h. meters per
4、 second _ _ m.p.s. feet per second _ _ _ f.p. s. 2. GENERAL SYMBOLS Weigbt=my Stands.rd acceleration of gravity=9.80665 m/s2 or 32 .1740 ft.fsec.2 lIV Mass=-g Moment of inertia=mk2 (Indicate axis of radius of gyration k by proper subscript.) Coefficient of viscosity P, Kinematic viscosity p, Density
5、 (mass per unit volume) Standard density of dry air, 0.12497 kg_m-4_s2 at 15 C. and 760 rom; or 0.002378Ib.-ft.-4 sec.2 Specific weight of “standard“ au, 1.2255 kg/m3 or 0.07651lb./cu. ft. 3. AERODYNAMIC SYMBOLS Area Area of wing Gap Span Chord Aspect ratio True air speed Dynamic pressure= 4 p 112 L
6、ift, absolute coefficient OL= :S Drag, absolute coefficient OD= :; Profile drag, absolute coefficient ODO= S D Induced drag, absolute coefficient ODt= qS Parasite drag, absolute coefficient ODP=S Cross-wind force, absolute coefficient Oa= q Q, n, Vl p - !J. Angle of setting of wings (relative to thr
7、ust line) Angle of stabilizer setting (relative to thrust line) Resultant moment Resultant angular velocity Reynolds Number, where l is a linear diInension (e.g. , for a model airfoil 3 in. chord, 100 m.p.h. normal pressure at 15 C., the cor-responding number is 234,000; or for a model of 10 em chor
8、d, 40 m.p.s., the corresponding number is 274,000) Center-of-pressure coefficient (ratio of distance of c.p. from leading edge to chord length) Angle of attack Angle of downwash Angle of attack, infinite aspect ratio Angle of attack, induced Angle of attack, absolute (measured from zero lift positio
9、n) Flight-path angle R, Resultant force Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-/ I 47167-3f -1 REPORT No. 664 WIND-TUNNEL INVESTIGATION OF AN N. A. C. A. 23012 AIRFOIL WITH VARIOUS ARRANGEMENTS OF SLOTTED FLAPS By CARL 1. WENZINGER and THOMA
10、S A. HARRIS Lanller Memorial Aeronautical Laboratory , I Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS HEADQUABTEBS. NAVY BUILDING. WASHINGTON. D. C. LABORATORIES. LANGLEY FIELD. VA. Created by act of Con
11、gress approved March 3, 1915, for the supervision and direction of the scientific study of the problems of flight (U. S. Code, Title 50, Sec. 151). Its membership was increased to 15 by act apprOed :-larch 2, 1929. The members are appointed by the President, and serve as such without compensation. J
12、OSEPH S. AMES, Ph. D., Chairman, Baltimore, Md. V.EVAR BUSH, Se. D., Yice Chairman, Washington, D. C. CH.4.RLES G. ABBOT, Sc. D., Secretary, Smithsonian Institution. HENRY H. ARNOLD, Major General, United States Army, Chief of Air Corps, War Department. GEORGE H. BRETT, Brigadier General, United Sta
13、tes Army, Chief Matriel Division, Air Corps, Wright Field, Dayton, Ohio. LYM.4.N J. BRIGGS, Ph. D., Director, National Bureau of Standards. CI.1NroN M. HESTER, A. B., LL. B., Administrator, Civil Aeronautics Authority, ROBERT H. HINCKLEY, A. B., Chairman, Civil Aeronautics Authority. JEROME C. HUNSA
14、KER, Sc. D., Cambridge, Mass. SYDNEY M. KRAUS, Captain, United States Navy, Bureau of Aeronautics, :-Iavy Department. CHARLES A. LINDBERGH, LL. D., New York City. FRANCIS W. REICHELDERFER, A. B., Chief, United States Weather Bureau. JOHN H. TOWIIBS, Rear Admiral, United States Navy, Chief, Bureau of
15、 Aeronautics, Navy Department. EDWARD WARNER, Sc. D., Greenwich, Conn. ORVILLE WRIGHT, Sc. D., Dayton, Ohio. GEORGE W. LEWIS, Director oj Aeronautical Research JOHN F. VICTORY, Secretary HENRY J. E. REID, Engineer-in-Charge, Langley Memorial Aeronautical Laboratory, Langley Field, Va. JOHN J. IDE, T
16、echnical Assistant in Europe, Paris, France AERODYNAMICS POWD PLANTS POR AIRCRAFT AIRCRAFT MATEBlALS TECHNICAL COMMITTEES Coordination oj Re8earch Needs oj Military and Civil Aviation Preparation oj Research Programs Allocation oj Problems Prevention oj Duplication Consideration oj Invention. AIRCRA
17、FT STRUCTURES AIRCRAFT ACCIDENTS I!IVENTlONS AND DESIGNS LANGLEY MEMORIAL AERONAUTlCAL LABORATORY LANGLEY FIELD. VA. OFFICE OF AERONAUTICAL INTELLIGENCE WASHINGTON. D. C. Unified conduct, for all agencies, of scientific research on the fundamental problems of flight. Collection, classification, comp
18、ilation, and dissemination of scientific and technical information on aeronautics . I I , Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-REPORT NO. 664 WIND-TUNNEL INVESTIGATION OF AN N. A. C. A. 23012 AIRFOIL WITH VARIOUS ARRANGEMENTS OF SLOTTED FL
19、APS By CARL J. WENZINOER and THOMAS A. HARRIS SUMMARY An investigation was made in the 7- by 10100t wind tunnel and in the variable-density wind tunnel of the N. A. O. A. 23012 airfoil with various slotted-flap ar rangements. The purpose oj the investigation in the 7-by 10100t wind tunnel was to dte
20、rmine the airjoil section aerodynamic characteristics aa affected by flap shape, slot shape, and flap location. The flap position for maximum lift; polarsjor arrangements consickredjaoorabkjor take off and climb; and complete lift, drag, and pitching moment characteristics jor selected optimum arran
21、ge ment8 were cktermiTUd. The be8t arrangement was tested in the variable-density tunnel at an effective Rey nolds Number oj 8,000,000. In addition, datafrom both wind tunnels are incluckd for plain, SPJit, external-air foil, and Fowler flapsjor purp08e8 oj comparisim. TM optimum arrangement oj the
22、810Ued flap was 8Uperior to the plain, the split, and the ezternal-airjoil type8 oj flap on the basis oj 17UJ.2imum lift coefficient, low drag at mockrate and high lift Coefficient8, and high drag at high lift coefficient8. The increment oj 17UJ.2imum lift due to the 810Ued flap was Jound to be prac
23、tically independent oj the Reynolds Number over the range inve8tigated. The 810Ued flap, however, gave slightly lower maximum lift coefficient8 than the Fowler flap. It was jound that 810t opening8 in the airjoil 8Urjace at the flap caused a mea8Urable increaae in drag oj the airjoil for the conditi
24、on oj high-speed flight even if the 810t was smoothly 8ealed on the upper 8Urjace and there was 11,0 flow through the 81ot. It was also jound that, in order to obtain the highest lift coefficient8, the M8e oj the flap should be located slightly ahead oj and below a slot lip that direct8 the air down
25、ward over the flap. The M8e oj the flap should have a good aerodynamic jorm and the slot entMJ shOl.dd have an easy shape to obtain low drags at mOckrate lift coefficients. INTRODUCTION Most present-day airpllUles, because of their high wing loadings and cleanness of aerodynamir deRign, employ some
26、form of lift-increasing and drag-increasing device to assist in landing them in a field of restricted size. Also, increases in lift without increases in drag appear desirable in the take-uff and in the climbing conditions of flight. The foregoing considerations indicate that the most desirable form
27、of high-lift device is one capable of providing high lift with relatively low drag, and also probably high lift with high drag. Some other desirable aerodynamic features are: no increase in drag with the flap neutral; small changes in wing pitching moment with flap deflection; low forces required to
28、 operate the flap; and freedom from possible hazard due to icing. Some form of slotted flap was believed to be the most promising for the conditions noted. Various forms of slotted flap include the external-airfoil (references I and 2), the Fowler (references 3 and 4), and the Handley Page types (re
29、ferences 5, 6, 7, 8, and 9). The present investigation was made in two main parts. The ts reported in part I were made in the 7-by IO-foot tunnel of slotted flaps somewhat similar to the Handley Page type. Flaps of three different sec tions and with several different slot shapes were tested. Surveys
30、 were made of flap location to obtain the best aerodynamic characteristics for each arrangement. In addition, a plain flap, a split flap, an external-airfoil flap, and a Fowler flap were included for purposes of comparison. Part II reports tests made in the variable-density tunnel of the best slotte
31、d flap arrangement (2-h) de veloped in part I, to determine the effects at high Rey nolds Numbers. In addition, slotted flap 2-h was tested in combination with a 60-percent-chord plain flap to see whether, as in previous unpublished tests of the plain flap alone, rounded lift-curve peaks could be ob
32、tained. The tests reported in part II were made by the var iable-density-tunnel staff and the material presented as part II was prepared for publication by Harry Green berg and Neal Tetervin. I. TESTS IN 7- BY to-FOOT WIND TUNNEL APPARATUS AND TESTS THE MODInED 7. BY to-rOOT WIND TUNNEL Before the p
33、resent investigation was started, the 7-by IO-foot open-jet wind tunnel (reference 10) had been modified, mainly by the addition of a closed test 1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-2 REPORT NO. 664-NATIONAL ADVISORY COMMITTEE FOR AERON
34、AUTICS section and a new entrance cone! (See fig. 1.) With these changes, the static pressure is practically constant along the axis of the test section and the noise during tunnel operation is fairly low. In addition, by making the top and the bottom of the test section parallel, an arrangement is
35、obtained whereby two-dimensional-flow tests can conveniently be made of large-chord models completely spanning the jet in a vertical plane. The use of such an installation permits a large ratio of chord of model to height of jet together with small wind-tunnel corrections (references 11 and 12) so t
36、hat the range of Reynolds Numbers of the tests for obtaining airfoil Horizontal sec lion tween the model and the tunnel walls is indicated by the flashing of neon lamps connected in an electrical circuit including the walls of the test section and thin metal plates fastened to each end of the model.
37、 The standard force-test tripod used with the pre vious open-jet wind tunnel (reference 10) to support horizontally the smaller finite-aspect-ratio models has been replaced by a single cantilever streamline strut. The opening in the floor of the closed test section through which the strut passes is
38、made airtight by a mercury seal. The existing scales are used with both types of test; however, in the case of the two-dimen-632- c Vertical secfion E, hoaeyoomb. H, propeller. A,eatranoeccme. B,esltcou. C, retum pun . 0, plde yane F, balance IIId model IUpportlDI strut. I, motor, 200 hp. J, statIc
39、platlll. G,model. K, 8Dtlawlrl YIIIIII. F10UKJ: 1.-DIairam 01 the 7 by 11).100t wind tUDDel with eloeed teat _tloD. section data in a given wind tunnel can be considerably increased. The wind-tunnel balance has been slightly modified by installing tubular supports on the top and the bottom of the ba
40、lance frame surrounding the test section se “lilt the model can be held vertical. The tubular supports extend through circular holes in the closed test section to sockets with clamps in the ends of the model; they can be rotated with II. motor drive by gears and shafting to change the angle of attac
41、k from outside the wind tunnel. A clearance of about 2 inch is allowed between the ends of the model and the top and the bottom of the test section (fig. 2). Any contact be-sional-flow tests, lift is measured on the cross-wind scale and pitching moment on the yawing-moment scale. (See reference 10 f
42、or arrangement of scales.) Sphere tests have been made to obtain an indication of the turbulence present in the air stream of the closed test section. The turbulence was found to have changed slightly from that of the open-jet wind tunnel, so that the turbulence factor (reference 13) has been increa
43、sed from a value of 1.4 to 1.6. The dynamic pressure of the air stream at the working section in either horizontal or vertical planes is constant within 0.5 percent, and the air stream is parallel to the axes of the test section within 0.5. Provided by IHSNot for ResaleNo reproduction or networking
44、permitted without license from IHS-,-,-AN N. A. C. A. 23012 AIRFOIL WITH SLOTTED FLAPS 3 MODELS Plain airfoil.-The basic model, or plain airfoil, (fig. 3) was built of laminated pine to the N. A. C. A. 23012 section (table I) and has a chord of 3 feet and a span of 7 feet. The trailing-edge portion
45、of this airfoil was made easily removable so that the model can be quickly altered for testing different flap arrangements. Wind dirction , Solonce frome , I , I , , , , , I , , , , , ., , “ , , , , , , , . , , , , , : ,: , , : , . , , ! 3,-J I ;., -+-+- . -t-. I VerI/col sction FI0171U: 2.-Model ID
46、lltailatiOD ror two-dlmeDSionlll!,-“ teets In the 7. by lroot wtnd tunnel. Split dap.-A simple split fla.p with a chord 20 p“ cent of the airfoil chord (fig. 3) was used in conjunctim with the plain airfoil. This flap is of plywood, 4 mcl! thick, and is fastened to the model by scre s. The flap angl
47、es (0 to 75) are set by wooden blocks cut to the desired angles and placed between the flap and the airfoil. Plain fiap.-The plain flap (fig. 3) also has a chord 20 percent of the airfoil chord and is mounted on a removable section, which replaces that of the plain airfoil. Fittings supporting the w
48、ooden flap are of thin steel and are equipped with ball-bearing hinges so that the hinge moments of the flap can be measured. The flap angles (38 up to 75 down) are set by a push rod and bell cranks, so arranged that the settings can be changed from outside the wind tunnel. The gap between the flap and the airfoil is sealed top Ilnd bottom by thin metal plates. Removab/e -_ -,-.80Ble-! _ c- BOOOe . I I-c i _C ,:R-.08/1e ci _
