1、LOW-SPEED LONGITUDINAL AERODYNAMIC CHARACTERISTICS 0F.A . . - “ . . 450 SWEPTBACK WING-WITH DOUBLESLOTTED FLAPS i . . (. By Rodger L. Naeseth :, . - “ ., “ Langley Aeronautical Laboratory Langley Field, Va. - .LA,slE- .+ :? : ,A L“i PPT T1 . r1-1 pr.q- 58 . . Provided by IHSNot for ResaleNo reproduc
2、tion or networking permitted without license from IHS-,-,-I NACA RM 5610 NATIONAL ADVISORY COMMIlTEE FOR AERONAUTICS RESEARCH MEMORANDZM LOW-SPEED LONGITUD- AERODYNAMIC CHARACTERISTICS OF A 45O SWEPTBACK WING WITH DOUBLE SLOTTED FLAPS By Rodger L. Naeseth SUMMARY A low-speed investigation has been m
3、ade to determine the effect of double slotted Claps consisting of a 0.213-wing-chord main flap and either a 0.500-flap-chord vane or a 0.266-flap-chord vane on the aerodynamic characteristics of a 45O sweptback wing. The flap had a span of 0.35 wing semispan with the inboard end at 0.16 semispan. Th
4、e wing had an aspect ratio of 3.7, a taper ratio of 0.41, symmetrical sections, and an average streamwise thickness ratio of 0.086. The test Reynolds number was 1.8 X 10 , based on the wing mean aerodynamic chord. 6 The double slotted flaps maintained effectiveness to high flap- deflection angles an
5、d, at an angle of attack of Oo, produced lift- coefficient increments of 0.67 at a flap deflection of 800 for the configuration with the 0.500-f lap-chord vane and 0.55 at a flap def lec- tion of 66O for the flap with the 0.266-f lap-chord vane. The stall of the two double-slotted-flap configuration
6、s occurred at an angle of attack which was about one-half the angle of attack at which the plain wing stalled and resulted in a maximum lift coefficient for the flapped configurations which was about 0.15 higher than the maximum lift coefficient of 1.02 attained by the plain wing. The maximum lift c
7、oeffi- cients of the double-slotted-flap configurations were about the same. For compasison with the double slotted flaps, either or both of the slots in the flaps were blocked and faked, thus simulating single slotted flaps or extended plagn flaps. The results indicated that, at moderate flap defle
8、ctions and angles of attack, blocking the slots increased the lift effectiveness slightly; however, the blocked flaps lost effectiveness at lower flap deflections than the slotted flaps with the consequence that the maximum lift obtained was somewhat lower than the maximum lift obtained for the doub
9、le slotted flaps. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-2 INTRODIETION NACA RM 5610 An investigation is being made by the National Advlsory Committee for Aeronautics to study the characteristics of various high-lift devices on a full-scale
10、45O sweptback wing. One-fifth scale tests of the double- slotted-flap designs proposed for tests at full scale were made in the Langley 300 MPH 7- by 10-foot tunnel to determine the effect of the flaps on the longitudinal aerodynamic characteristics of the sweptback wing. The wing had a.n aspect rat
11、io of 3.7, symmetrical sections, a taper ratio of 0.41, and an average streamwise thickness ratio of 0.086. Ln order that the design of the double slotted flaps developed in the small-scale tests can be used in the full-scale tests, the same span of flap (0.35 semispan) and the same forward limZt of
12、 space for retrac- tion (0.735 wing chord line) were used. Two double-slotted-flap config- urations were used. For one, a ratio of vane chord to flap chord of one-half was chosen because it was shown to be optimm in a summasy of existing two-dimensional, data (ref. 1). The flap, rearward of the vane
13、, was 0.213 wing chord, For the other design, a smaller vme (0.266 flap chord), fixed to the flap, was chosen because it would require a less complicated retracting mechanism. For comparison with the double-slotted-flap characteristics, the characteristics of a single-slotted-flap arrangement and an
14、 extended plain flap were obtained. The single. slotted flap was simulated by blocking either of the slots, and the extended plain flap by blocking both slots. The forces and moments measured on the wing are presented about the wind axes which, for the conditions of these tests (zero sideslip), corr
15、espond to the stability axes. ! and the 0.266 vane was the largest vane which could be retracted into the designated space without relative move- ment between vane and flap. St Cyr 156 sections, reference 2, were used for the vanes because the rounded leading edge of the section allows deflection of
16、 the vane-flap assembly as a unit about a fixed pivot through a large angle range while maintaining a desirable lip and vane relation- ship, figure 2; also the sections remain unstalled over a large angle- of -attack range. The flap-def lection angles were measured in the plane of the flap ends, tha
17、t is, normal to a line swept 36.77. 2 2 Provision was made for minor chauges in the flap geometry. The flap and O.5OOcf vane assembly pivot point could be moved forward a distance of Om024cf, down a distance of 00012cf,A, (fig. 3(a), or the flap part Could be moved forward along its chord plane rela
18、tive to the vane a distance of 0.062, (fig. 3(b). The lower surface wing lip was removable. Filler blocks of balsa wood were provided to block the slots (fig. 4). The wing was aluminum except for the trailing-edge modification mentioned previously and the flap, both of which were made of mahogany re
19、inforced with an aluminum plate extending to the trailing edge. The vanes were machined from aluminum. The larger of the vanes was supported at each end, the smaller vane required a center support in addition to the end supports. The semispan-wing model was mounted vertically in the Langley 300 MPE
20、7- by 10-foot tunnel. The root chord of the model was adjacent to the ceiling of the tunnel which served as a reflection plane. A small clearance was maintained between the model and the tunneb ceiling so that no part of the model came into contact with the tunnel structure. In order to minimize the
21、 effect of spanwise air flow over the model through this clearance hole, a 1/16-inch-thick metal end plate, which projected about 1 inch above the wing surface, was attached to the root of the model. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NA
22、CA RM 5610 - 5 TESTS AND COF3EZTIONS Description of Tests Data were obtained through an angle-of-attack range of -6 to 26O for all codigurations and tne flap-deflection range extended to 80.4O. me configurations tested a;nd flap-deflection ranges are summarized in table 111. The tests were performed
23、 at 89 average dynamic pressure of approx- imately 25.4 pounds per square foot, which corresponds to a Mach number of 0.13 and a Reynolds number of 1.8 x 10 based on the wlng mean aerodynamic chord. 6 Corrections Jet-boundary corrections, determined by the method presented in reference 3 have been a
24、pplied to the angle-of-attack and the drag coef- ficient values. Blocking corrections, to account for the constriction effects of the model and its wake have also been applied to the test data. The blocking corrections were computed by the method of reference 4. RESULTS AND DISCUSSION Presentation o
25、f Results The lift, drag, and pitching-moment characteristics are presented for the wing and flap with the O.5OOcf vane in figures 5 to 9 and for the wing and flap with the 0.266c-f vane in figures 10 to 13. Character- istics of the plain wing are included in each figure. Figures 14 to 17 are summar
26、ies of the lift increment for the range of flap deflections tested and are given for angles of attack of Oo, hO, and loo. Lift Characteristics Plain wing.- Plain-wing results show a lift-curve slope of 0.053 at a = Oo. The lift-curve slope begins to increase at CL = 0.30 and appears typical of swept
27、 wings havkg leading-edge-separation-vortex- “pe flow. The maximum lift coefficient was 1.02 and was obtained at an. angle of attack of 24. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-6 NACA RM 5610 Flap with 0.500cf vane.- The results for the wi
28、ng with double slotted flaps with the O.5OOcf vane, figure 5, indicated a lift coeffi- cient increment at a = Oo of 0.67 obtained with 6f = 80.4O; however the stall of the flapped wing occurred at about 12O angle of attack, much lower than the plain wing which had maximum CL at a = 24O, and resulted
29、, therefore, in a maximum lift coefficient for %be flapped configuration which was about 0 .l5 higher than the IUaximum lift coefficient of 1.02 attained by the plain wing. For comparison with the double slotted flap the characteristics of a single slotted flap and extended plain flap were obtained.
30、 The single slotted flap was simulated by blockirig either of the slots and the extended plain flap by blocking both slots. The results, figures 6 to 8, show a similar variation of lift coefficient with angle of attack for these configurations as compared to the double slotted flap. When both slots
31、were blocked, figure 8, the curves for 6f = 65.4O and 70.70 show a sharp loss in lift above a = 0. A similar result occurred with the rear slot blocked (fig. 6). The Fncrements of lift coefficient for the double slotted flaps and various modifications are compared in figures 14 and 15 at three angle
32、s of attack. At a = Oo the double-slotted-flap-lift increment increased with deflection through the maximum angle tested, 80.4O, where hc was 0.67. At a = loo this maximum increment had decreased to 0.38 and was obtained with a flap deflection of 75.6O. Blocking of either or both of the slots result
33、ed in an increase in bf! at the lower flap deflec- tions; however, earlier stall as the flap deflections were increased limited the maximum EL attained by the flaps with either or both slots blocked to values somewhat less than those of the double slotted flap. This difference between the maximum AC
34、L for the double slotted flap and the flaps with one or both slots blocked was small (generally less -than O. and at flap deflections of about 65O and greater, the marked changes in the lift curves discussed previously had correspondingly large changes in CmYw(about 0.05 decrease in Cm,w . between a
35、 = Oo, and a = 2). A similar effect is shown in figure 6 for the flap with rear slot blocked. Generally the same trends were shown for the flap and small vane (figs. 10 to 13), except that the unstable break in the pitching-moment- coefficient curve occurs at a lower lift coefficient than for the fl
36、ap and large vane. Wag Characteristics Analysis of the lift and drag data indicates that, for lift coeffi- cients in the range just below stall, a flap deflection of about 50 provides the highest value of lift-drag ratio (about 3.9). Further increases in flap deflection generally result in a decreas
37、e in lift-drag ratio. Therefore an advantage may be gained by lhiting the flap deflec- tions. When high drag coefficients are desirable to increase the glide- path angle or when a lower angle of attack is desirable, higher angles of deflection may be used. Lift-drag ratios for the various flaps show
38、ed little difference at these high-lift coefficients. A low-speed investigation has been made to determine the effect of double slotted flaps consisting of a 0.213-wing-chord main flap and either a 0.500-flap-chord vane or a 0.266-flap-chord vane on the aero- dynamic chasacteristics of a 45 sweptbac
39、k wing. The wing had an aspect ratio of 3.7, a taper ratio of 0.41, and an average thickness ratio of 0.086. The test Reynolds number was 1.8 X 10 , based on the mean aerodynamic chord. 6 The double slotted flaps maintained effectiveness to high flap deflections and, at an angle of attack of Oo, pro
40、duced lift-coefficient increments of 0.67 at a flap deflection of about 80 for the flap with 0.500-f lap-chord vane and 0.55 at a flap deflection of about 66 for the flap with the 0.266-flap-chord vane. The stall of the two double-slotted- flap configurations occurred at an angle of attack which was
41、 about one-half - Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA RM 5610 9 the angle of attack at which the plain wing stalled and resulted in a maximum lift coefficient for the flapped configurations which was about 0.15 higher than the maximu
42、m lift coefficient of 1.02 attained by the plain wing. The maximum lift coefficients of the two flapped configu- rations were about the same . For comparison with the double slotted flaps, slots in the flaps were blocked and faired thus simulatbg single slotted flaps or extended plain flaps. The res
43、ults indicated that, at moderate flap deflections and angles of attack, blocking either or both of the slots increased the lift effectiveness slightly; however, the blocked flaps lost effec- tiveness at lower flap deflections than the slbtted flaps with the consequence that the maximum lift obtained
44、 was somewhat lower than the maximum lift dbtained for the double slotted flaps. Langley Aeronautical Laboratory, National Advisory Committee for Aeronautics, Langley Field, Va., December 21, 1955. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-10 N
45、ACA RM 5610 REFERENCES 1. Riebe, John M.: A Correlation of Two-Dimensional Data on Lift CoefCicient Available With Blowing-, Suction-, Slotted-, and Plain- Flap High-Lift Devices. NACA RM L55D29a, lB5. 2. National Advisory Committee for Aeronautics: Aerodynamic Character- istics of Airfoils. NACA Re
46、p. 315, 1929. 3. Gillis, Clarence L., Polhamus, Edward C., aml Gray, Joseph L., Jr.: Charts for Determining Jet-Boundary Corrections for Complete Models in 7- by 10-Foot Closed Rectangular Wind Tunnels. NACA WR L-123, 1945. (Formerly NACA ARFl L5G31. ) 4. Herriot, John G.: Blockage Corrections for T
47、hree-Dimensional-Flow Closed-Throat Wind Tunnels, With Consideration of the Effect of Compressibility. NACA Rep. 995, 1950. (Supersedes NACA RM A7B28 ) 5. DeYoung, John. : Theoretical Symmetric Span Loading Due to Flap Deflection for Wings of Arbitrary Plan Form at Subsonic Speeds. NACA Rep. 1071, 1
48、952. (Supersedes NACA TN 2278.) 6. Swanson, Robert S., and Crandall, Stewart M.: Lifting-Surface-Theory Aspect-Ratio Corrections to the Lift and Hinge-Moment Parameters for Full-Span Elevators on Horizontal Tail Surfaces. NACA Rep. 911, 1948. (Supersedes NACA TN U75. ) Provided by IHSNot for ResaleN
49、o reproduction or networking permitted without license from IHS-,-,-NACA RM 5610 TABLE 1 11 SPANVISE STATIONS 1 AND 2 I Station 1; chord, 20.613 in. Station 0 .44 .66 1.11 2.22 4.44 6.66 8.89 13.34 17.80 22.27 26.75 31.22 40.20 44.70 49.20 35 71 60.30 68.92 a74.07 80.87 87.66 94.45 100.00 Ordinate 0 .82 99 1.23 1.67 2.8
