1、REPORT No. 679WIND-TUNNEL INVESTIGATION OF AN N. A. C. A. 23012 AIRFOIL WITH A SLOTTEDFLAP AND THREE TYPES OF AUXILIARYBy CARL J. WEIWNC+EE and WILLIAM E. GAUVAINSUMMARYAn inrestioation ums made in ih N. A. C. A. 7- bw10+ot m“nd tunnel to determine the aerodynamic sethis flap together with its sIot
2、shape(fig. 1) is the same as the arrangement designated 2-hin reference 1. The flap was mounted on the airfoilwith three fittings aIong the span that permitted settingthe flap at the optimum location for each deflection.699Provided by IHSNot for ResaleNo reproduction or networking permitted without
3、license from IHS-,-,-700 REPORT NO, 679-NATIONAL:ADVTSORY COMMITTEE FOR AERONAUTICSThe ordinates for this flap and the slot shape arg givenin table 1, and the optimum path of the nose of the flapfor various deffectkms (from referenc8 1) is given infigure 2 (a). The nose point of the flap is defined
4、asthe point of tangency of a line drawn normal to theairfoil chord and tangent to the leading-edge arc of theflap when neutral.Pa% of flqo nosePath of %xiliary flap nose(n) Path of the mafn sfottwl flap for vrufons dektforrs on the N. A. 0. A. W312sMcdl. .2Path ofda noee forvarfon8flnpdeflectfcom Df
5、stam.es mewruWMmllOalOoflkr fnc“II I I81 mz(deg.) Yo 8.29 a91h41 a. 68: 2.82 the shapes of both the flap and the slot are similar tothose of the main slotted flap. The ordinates for thouxiliary slotted flap and the slot shape are also givenin table I. This flap was mounted on the main slottodflap by
6、 speckd fittings that allowed the small flap ta belocated. at any point over s considerable area withrespect to the main flap. This arrangement makes itpossible to determine the optimum locations of thesmall slottid flap for the various deflections investi-gated. (See fig. Z(b).)TESTINSTALLATIONThe
7、model was mounted in the closed teat section ofthe 7- by 10-foot wind tunnel so as to span the jotcompletely except for small clearance at each end.(See references 1 and 2.) The main airfoil was rigidlyattached to the balance frame by torque tubes, whichextended through the upper and the lower sidm
8、of thetunnel. The angle of attack of the model was set fromoutside the tunnel by rotating the torque tubes with acalibrated drive. Approximately two-dimensional flowis obt turbulence factorfor the tunnel is 1.6.)Tests were made of the airfoil similar data for the air-foil with the slotted flap and t
9、he O.lOCUsplit flap aregiven in figures 9 to 13. Envelope polar curves forthese arrangement are pIotted in figures 14 and 15.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted without
10、license from IHS-,-,-AN N. A. C. A. 23012 AIRFOHJ WITH SLOTTED AND AUXILIARY FLAPS 703-16 LII II t I , r 1 1 1 I z 1 ! 1 1 I 1-20 J IIo .2 .4 .6 .8 LO 1.2 L4 /.6 /.8 20 22 2.4 2.6 2.8 3.0Section lift coefficienfi clVarfa.,.-FIGUM 4.-Sectfou I ohmmtetlstks of the N. A. C. A. 2301!2airfoil with the ma
11、in dotted fhp deflected and the anstlkry 0.06% lt fM delld Ed Imounts.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-704 REPORT NO. 67NATIONAL ADVISORY COWTTEE FOR AERONAUTICSI I I I I 1 I mrfous amormts.FIouiI ii+ection ohsreetsufstke of UISN. A. 0
12、. A. 23012alrfofl w!th the main slottd Rep defiectd 1 s.nd the anxfllruy OJMsSsplit fiP defkcttiProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-AN N. A. C. A. 23012 AIRFOIL WITH SLOTIED AND AUXILIARY FLAPS 705.Secfion fiff coefficiwt etFmmx :and enve
13、lope polar curves for the combination meplotted in figure 25. the optimum paths chosen are shownin figures 22, 23, and 24. A beneficial effect wdl beobtained from the auxiliary dotted flap for fixed main-flapdeflectione of 20 and 40 when the auxiliary fiapis deflected at Iift coefficients beyond 1.3
14、5 and 2.46,COMPARISON OF THE FLAP ARRANGEMENTS TESTEIIAn envelope of each of the series of enveIope polarcurves given inres 14, 16,21, and 25 has been pIottedfor each flap arrangement in figure 26. This figureshows that, from lift coefficient.sof 1.1 up to the stall,the lift and the drag characteris
15、tics of the airfoil withthe main sIotted flap can be improved by the additionof an auxiliary flap of the split or dotted type. Thoauxiliary plain flap offers an improvement over onlytwo portions of the lift range, between cl= 1.1 and 2.46and from 2.73 tc the stel.L The superiority of the mainslotted
16、 flap with the auxihy slotted flap for high liftwith. low drag, which is very important for take-offand steep angIee of climb, is immediately evident.E in the last two columns are given the ratioof lift to drag at maximum lift (an indication of thesteepest gliding angle available), and the ratio of
17、maxi-mum lift to the drag at a lift coefficient of 0.2 (criterionof the speed range). The main slotted flap with thoauxiliary slotted flap also shows up favorably in themcomparisons, except as regards the pitching moments.For nearIy all conditions, this combination has thehighe+t-pitching moments of
18、 the arrangements testmland this characteristic must be given consideration inapplications ta design.The effect of the various flap arrangements in in-creasing the maximum lift of the airfoil is shown infigure 27 where values of the maxinmdift incrementACInu are plotted against deflections of the mu
19、riliaryflaps for given deflections of the main slotted flap.The superiority of the main slotted flap with theauxiliary dotted flap is immediately evident. It willbe noted that, with the main slotted flap deflected 40fits setting for Cka) and the auxiIiary sIotted flapdeflected 30 or 40, an increase
20、of 1.46 in the maxi-mum lift coefficient is posaibIe. This increwe almostProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-AN N. A. C. A. 28012 AIREOKL WITH S AND AY 725doubles the maximum lift Of the 60;03CONCLUSIONS1. The optimum arnmgement of the ma
21、in and theauxiliary flap combinations tested is the main sIottedflap with the auxiliary sIotted flap, whioh has morefavorable oharaoteristios than the single main slottedflap on the basis of maximum lift Ooeflioklllt,low dragat moderate and high lift coefficients, and high drag athigh Iift coeflioie
22、nta.2. The auxiliary split flap or the auxiliary plain flapcombined with the main slotted flap slightly improvesthe aerodynamic characteristics of the wing and flapcombination at high lift ooeffioients.3. All auxiliary flaps tested in combination with thewing and the main flap increase the magritude
23、a of thepitohing moments over those of the wing and the mainsIotted flap alone.Center ofma89.69 1.62Eadfk: .M6 -.308 20 1!I17.w z4% oii o.0a7 -.2M xl o: 116.69 !24h2-.247 20 0:% -.863 alM2 .lr -. -L:Ra -.70.18 -.ls I3tatton Ordinsta WITH AUXILIARY O.lOcmP- BLAPl 0 1: :IJ4 -o. OM oLo -.240 2! o.0x3 -
24、.253 o;: .042 -. ra7 o t 17.lul 2426.079 -.846 I HO .16 -. m AWITH AUXILIARY O.10c_SLOTTED FLAPOenterofemtied 407 La ylJ -o. OzYl-.246 J1.020 -. 64s !al.039 -. 4r4 m.006.400 20.17 -.620 40Epmlc of cm:O&h&r oflyul#dsIu:Lw.dfng+3.Keradlns 04LI Mlnlmnm drag.mo14247Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
