1、/,-i.-.IATIONAL ADVISORY COMMITTW3 FOR.HO. 472*-.“”*-M3ROl?KdT!ICS., - .-.THE AERODYNAMIC C“WLRAC2ERISTICS OF A CLARKBY Carl J. VenzingerOilY im!ii”“ .Langley Memorial Aeronautical Laboratory -. _l?ashingtoSeptember 1933. . . .-. . _ ,_ .J. -_._-._. . .-.,-.Provided by IHSNot for ResaleNo reproducti
2、on or networking permitted without license from IHS-,-,-,/“? f,.llllllllll:llllllllllllrllllllrlll311760 i4331384 +.- -NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS.TECHNICAL NOTE NO. 4?2 -.THE ETl?ECT OF PARTIAL-SPAN SPLIT FLAPS ON THEAERODYNAMIC CHARACTERISTICS 03ACLARK Y WINGBy Carl J. WenzingerSUM
3、MARYAerodynamic force tests were made in the N.A.C.A. 7by 10 foot wind tunnel on a model Clak Y wing with a 20percent chord split flap deflected 60 downward. Thetests were made to determine the effect of partial-spansplit flaps, located at various pos5tions along the wing -span, on the aerodynamic c
4、haracteristics of the wtng-anii-flap combination. The different lengths and locations of9the flaps were obtained by cutting off portions of a full-span flap, first from tho tips and then from the center9The results are given in the form of curves d-flif%,drag, and center of pressure. They show that
5、with partial-*span split flaps both the lift and drag are less than withfull-span flaps; that the lift for a given length of flapis somewhat greater when the partial span is located atthe center of the wing than when it is located at the tipportion; and that the drag for a given length of flap isthe
6、 same regardless of the location of the flap with re-spect to the wing span.INTRODUCTIONAmong the devices for increasing the maximum lift andalso the drag of an airplane to improve the landing char-acteristics, is the split trailing-edge flap. With thisarrangement the rear portion of the wing is spl
7、it. into up-per and lower sections and the lower section is deflecteddownward as a flap. This type of flap is designed for useover the maximum possible length of the wing span, no pOr-tion of the flap serving for latera control. .Provided by IHSNot for ResaleNo reproduction or networking permitted w
8、ithout license from IHS-,-,-.2 N,.A:C.A. Technical iote No. 472. .,-,.,., :. .- d“Some tests have preiou,sly been made on airfoils withsplit flaps (refer e”nces1, 2,-3, and 4) in which the ef- ,fects of changes in flap chord and deflection have beenThe present investigation was mede to de-investigat
9、edqtermine the effects of changes in flap length and locationalong tho wing span. The flaps were tostod on a Clark Ywing in tho 7“by 10 foot wind %unnel$ which has an bjen test !jec-tion, is d,eseribed in detail togoth”er with tho balancesLrProvided by IHSNot for ResaleNo reproduction or networking
10、permitted without license from IHS-,-,-and stanard test procedure in reference 5. “ !lhe testswere made et an air speed of 80 miles per hour, corr=spending to a Reynolds Number of 609,000. The 6R$. werenot corrected for tunnel-wall effect. :RESULTS AND DISCUSSION .-TiD sections removedi-Curves of C.
11、- _,.iJ), and c.p.are given in figure 3 for the wing hav ng split flaps withdifferent amounts removed from both tips. It will be Beenthat the peake of the lift curves have a sharp drop justafter the stall as compared with that for the plain wing,and that the lift and the drag deorease with increase
12、inthe amount of fp removed. The center of pressure in theregion of maximum lift is about 10 percent of the chordfarther aft for the wing with full-span flap than for theplain wing.Center sections removed.- Curves of CL ,-._- _ CD, andc.p. are given in figure 4-for the wing having split flapswith dif
13、ferent amounts removed from the center of the span.The peaks of these lift curves gradually round off at the#stall with iucrease in the amount of flap removed, and”thelift and the drag decrease. The change in the center of pressure with variation of flap length is about the same-.-as for the fltip w
14、ith tip sections removed.7Comparison of effect .of removl.ng sections from the.- .- -.-i,and From tle center.- Curves of-.-.-_._ L max and of C; “atCL max against eplit-flap length are gtven in l?iguie both for tip sections Temoved and cen;er sectione remove.This. figure shows .that a,somewkat aalle
15、r:part of the “.maximum lift is lost by cutting off the tip sections thanby removing center eections of the same total length. Itshould b noted that the drag at maximum lift is affectedonly by the length of the flap afid does not depend onw-nether the section is removed from the tips or the center.
16、-.qCONCLUilONSJ. Both the lift and the drag of a wing with partial-epan split flaps are less than those with full-span flaps,the lift for a given length of flap being somewhat greater ,b. .+Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4 N,A,C.A. T
17、echnical. Note, No., ,4?2when the partial-span flap is located at ths center ofthe wing. than when it is located at the tip portion. Thedrag for a given length of flap is the same regardless ofthe location of the flap with respect to the wing span.Langley Memorial Aeronautical Laborator.,-National A
18、dvisory Committee for Aeronautic,Langley Field, Vs., J711y 12, 1933.REFERENCES%amber , Millard J.: Wind, Tunnel Tests on an AirfoilEquipped with a Split Flap and a Slot. TON! No.324, .N.A.C,A, 1929.Noda, Tetsumo: The Hiraki-3ane Variable SectionAirfoil. Abstract .irn,Mech. n,g., vol. 55, no. 6,Juno
19、1931i p 448. ,Welck, l?red E., and Harris, Thomas A.: The Aerody-namic Characteristics of a Model Wing Having aSplit l?lap Deflected Downward and Moved to theRear . T.l?. MO. 422, N.A.C.A, 1932,Gruschwitz, Eugen und Schrenkt 06kar: A Simple Meth-od for Increasing the Li47*93*63 4.42.15.03.00.00 -.00
20、a71 00,.00 y,. ._a71 00-m.00,00a71 00- - -.- . dProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-, .-. LFigure l.+ plit flap tested” on Clark Y wing.-1m.l-),4 I I!,Provided by IHSNot for ResaleNo reproduction or networking permitted without license fr
21、om IHS-,-,-“/, ,. ,f r II2.40- 2.40,./“ a F- A ()2.00 . 2.00 / / / /7 cL/ /1.60 / 1.60 / 4 ./CLm= f Plajnwing CLmu / / v I “ t Center remove d1.20 I 1.20- .60Reference 3a75 “ 4 ,:/ .80 .80 / =1 .40“40 w d “ “ “ “ “/1 “ CD- .40“ .20Clmr; lvo “lo 20 30 40 0 20 40 60 80 .100Flap chord, percent wing cho
22、rdFjgure 2.-Effect of chordof split flapon CLmmIFlap length,percent wing span -Figurd 5.-Effect of partial-span splitonCLW and on CD at cLmaxflapszt=Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-N.A.C.A. Technical Note No. -Fig. 3a71cc.,I: 20 “l-i
23、/fG IIIEw 4(3c)+LJJ:60a)laFull span split flap:m -0.80b split flap- .60b 9 .“,d 80. -.20b “r!1 +100 .D2.00 ,/f /?L/“y ,J o1.60/f / /1.20- ,/.8(3 / ,D .40 + ,0-“Angle of attack, -.+ “AH&K#t-t_4”u% J= I 1, I I I I I I I I I_160 -8” 0“ 89 16= 24 32” 40”Angle of attack, ciFigure 4.- Split flaps with center sections .remoxed ,-.- Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
