1、NASA TECHNICAL NOTE d 40 40 d I n z c 4 LA 4 I NASA TN D-4664 e- / h - - WIND-TUNNEL STUDY TO EXPLORE THE USE OF SLOT SPOILERS TO MODULATE THE FLAP-INDUCED LIFT OF A WING by Joseph W. Stickle and Robert C. Henry Langley Research Center - Langley Station, Humpton, Va. i t NATIONAL AERONAUTICS AND SPA
2、CE ADMINISTRATION WASHINGTON, D. C. JULY 1968 84 1 hI I 1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TECH LIBRARY KAFB, NM I llllll11111111111 IHI lllll11111llll Ill WIND-TUNNEL STUDY TO EXPLORE THE USE OF SLOT SPOILERS TO MODULATE THE FLAP-INDU
3、CED LIFT OF A WING By Joseph W. Stickle and Robert C. Henry Langley Research Center Langley Station, Hampton, Va. NATIONAL AERONAUT ICs AND SPACE ADMINISTRATION For sale by the Clearinghouse for Federal Scientific ond Technical Information Springfield, Virginia 22151 - CFSTI price $3.00 Provided by
4、IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I WND-TUNNEL STUDY TO EXPLORE THE USE OF SLOT SPOILERS TO MODULATE THE FLAP-INDUCED LIFT OF A WING By Joseph W. Stickle and Robert C. Henry Langley Research Center SUMMARY This report presents the results of a prel
5、iminary study to explore a proposed new concept for achieving direct lift control on an airplane. The concept employs variable- width slot-type spoilers to modulate the lift increment produced by a deflected flap. The study utilized a NACA 2509 constant-chord airfoil model wing modified to provide v
6、arious size slots on both the wing and flap sections. Each configuration was tested through an angle-of-attack range of -2O to 16O in a low-speed tunnel with a 12-foot octagonal test section at the Langley Research Center. The tests were conducted at a Reynolds number of approximately 410 000. effec
7、tive in controlling the lift increment obtained from flap deflection and that there is relatively little change in drag coefficient associated with slot-width changes. The results indicate that the use of a variable-width slot is INTRODUCTION Direct lift control is being considered for use on genera
8、l aviation aircraft as a pos- sible means to improve the piloting task during approach and landing. One of the potential problems in implementing a direct-lift-control system on a light airplane is the type of drive system to be employed. To date all the flight-tested direct-lift-control systems, em
9、ploying flaps or spoilers, have been driven by some form of electro-hydraulic system which is not commonly found on light airplanes. general aviation aircraft should be lightweight, simple, and inexpensive. A direct-lift-control system suitable for Such a system has been conceived which consists of
10、a variable width slot across the leading edge of a flap. The slot would vent a portion of the higher pressure air at the lower surface into the lower pressure air passing over the upper surfaces and, in effect, act as a spoiler. For direct lift control, a portion of the flap-induced lift would be sp
11、oiled and the lift control would be effected by symmetrically increasing or decreasing the slot widths as required. The present concept could also be used for lateral control by varying slot widths differentially. has been discussed in reference 1. The use of spoiler devices for lateral control is n
12、ot new and Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-In order to determine the feasibility of the concept, a wing-flap combination was used for exploratory tests in a low-speed tunnel with a 12-foot octagonal test section at the Langley Researc
13、h Center. For comparison, tests were also made with small fence- type spoilers. This report presents the results of the investigation. SYMBOLS lift coefficient CL CD drag coefficient Cm pitching- moment coefficient (referenced to 0.2 50cw) Q! angle of attack, deg b wing span, inches (meters) CW wing
14、 chord, inches (meters) C f flap chord, inches (meters) distance from wing leading edge to spoiler position on wing, inches (meters) 2, distance from flap trailing edge to spoiler position on flap, inches (meters) 2 f X width of slot spoiler, inches (meters) Y height of fence spoiler, inches (meters
15、) Subscript : max maximum WING MODEL AND TEST ARRANGEMENT The wing model used for the study had a NACA 2509 airfoil section with a 72-inch (See fig. 1.) The wing had two (1.82-m) span and 12.87-inch (0.33-m) constant chord. flap sections, each of which was 32.75 inches (0.83 m) long and 33 inches (0
16、.10 m) wide. 4 A three-component force balance was installed at the 25-percent chord line in the center of the wing and mounted as shown in the photograph of figure 2. The various 2 I i Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-configurations o
17、f slots and fence-type spoilers tested are shown in figure 3. In each con- figuration, the slot and fence spoilers covered the same spanwise position along the flap sections as shown in figure 1. TEST CONDITIONS The tunnel speed for all tests was set to provide a dynamic pressure of 4.34 pounds per
18、square foot (207.4 N/m2). The corresponding Reynolds number was approximately 410 000. model configuration was tested through an angle-of-attack range of -2O to 16O. wing was tested with 00 and 300 flap deflection; configurations with slot- and fence-type spoilers were tested with the flaps set at 3
19、0 only. for all tests. Structural limitations of the model prevented testing at higher pressures. Each The basic The flap-wing juncture was sealed RESULTS AND DISCUSSION Lift, drag, and pitching-moment coefficients for the configurations investigated are presented in figures 4 to 9. No corrections w
20、ere applied to the data since only relative effectiveness of the spoilers was of interest in this exploratory study. Slot Located on Flap Figure 4 presents data for the flap slot configurations C1, C2, and C3 compared with the basic wing configurations A and B. These data indicate that all the slot
21、widths are effective in reducing the values of lift coefficient below those of the basic flap, con- figuration B. Values for the 0.039 slot (configuration C1) show a reduction of about 60 percent of the CL increment between configurations A and B throughout the angle- of-attack range. At a given a,
22、there is little change in CD between the unslotted configuration (configuration B) and the fully opened slot (configuration Cl). For angles of attack below 100, the decrease in CD for configuration C1 is about 10 to 20 percent of the increment due to flap deflection. The decrease in pitching moment
23、of C1 is about 50 percent of the pitching-moment increment between configurations A and B. Figure 5 presents comparisons between two locations of the O.OIOcw slot on the flap configurations C3 and C4 and the tapered slot configuration D. that slot effectiveness is dependent on both shape and positio
24、n. The results indicate 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Slot Located on Wing The data of figure 6 show comparisons between the wing slot configurations El, E2, and E3 and the basic wing configurations A and B. It should be noted tha
25、t the CL curve for configuration B in figure 6 is slightly lower at CL,mx than the corresponding curve of figures 4 and 7. This effect probably was a result of the additional bracing that was added to support the flap with the wing slot open. At an angle of attack of Oo, the 0.039 wing slot (configu
26、ration El) shows a reduction in CL of about 50 percent of the incre- ment due to flap deflection. Near CL,mz, however, the 0.039 slot has effectively reduced all the lift increment of the flap. Thus, the slot located on the wing decreases both the magnitude of lift and slope of the lift curve. Compa
27、rison of Slot Spoilers With Fence Spoilers In order to provide a basis for comparing the effectiveness of the slot spoiler con- cept with the more conventional fence-type spoilers, configurations F, G, and H were tested. Figure 7 shows.the results of configuration F compared with the basic wing conf
28、igu- rations A and B. installed on the flap near the leading edge. (See fig. 2.) It is apparent that neither spoiler configuration F1 or F2 was effective in reducing lift and, in fact, tended to increase the lift above that of the basic 30 flap. This slight increase in lift is possibly brought about
29、 by turbulence induced by the spoiler in the boundary layer giving slightly better flow adhe- sion over the flap. Tufts located along the flap indicated that the flow was not separated by the fence spoilers. Configurations F1 and F2 consisted of 0.019cw and 0.046 high fences Comparison of the result
30、s for the 0.019cw fence spoiler located on the wing at the 68-percent chord (configuration G) and the slotted flap configurations C1 and C4 is shown in figure 8. At lower angles of attack, the fence spoiler decreased the lift to approxi- mately the same value as the 0.039 slot (configuration C1); ho
31、wever, it loses effective- ness with increasing angle of attack and approaches the CL curve of the 0.010 slot (configuration C4) near CL,mz. Figure 9 gives the results for configuration H (fence spoiler at the 30-percent chord) compared with the slot configuration C1 and the basic wing configuration
32、s A and B. Above an angle of attack of about 4O, the fence spoiler is more effective in reducing the lift than the slot; however, the drag increment is considerably greater than that for the slotted configuration and the pitching moment is somewhat nonlinear. 4 Provided by IHSNot for ResaleNo reprod
33、uction or networking permitted without license from IHS-,-,-CONCLUDING REMARKS Based on the results of this investigation, it was apparent that the use of a variable- width slot was effective in controlling the increment of lift obtained from flap deflection. At a given angle of attack, there was li
34、ttle drag coefficient change associated with slot- width changes. Slot location, shape, and width were shown to affect the magnitude of lift control achieved. Langley Research Center, National Aeronautics and Space Administration, Langley Station, Hampton, Va., May 3, 1968, 126- 6 1-04-07- 23. REFER
35、ENCE 1. Langley Research Staff (Compiled by Thomas A. Toll): Summary of Lateral-Control Research. NACA Rep. 868, 1947. (Supersedes NACA TN 1245.) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- 72.000 in. _ 1 (1.828 m) I - -7- Figure 1.- Sketch of m
36、odel wing. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Figure 2,- Photograph of wlng model sting mounted In tunnel. L-68-942.1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Configuration Chord s
37、ection I)- n G -_ F-% % = 12-785 inches f = 3.750 inches (.327 meter) (-095 meter) Slot location “w Cl -235 C4 .220 C2 .245 C3 .249 “/% D .220 Spoiler location “/% Fl -254 F2 .25k Slot width pw - 039 .or9 - 010 - or0 .or0 to -294 (tapered) 5/41 - 039 . org .010 Spotler height X/Cw I - org pw .olg Fi
38、gure 3.- Chord sedion view of configurations tested. 8 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-W cL cD 1.2 1.c .a - .6 .4 .2 0 -5 0 10 1 a, degrees 20 0 5 10 CL, degrees Figure 4.- Comparison of longitudinal characteristics between various si
39、ze slots located on the flap and the basic wing configuration. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-c-. 0 1. 1 CL 1 CD 4 .2 front .o rear 8 6 4 2 0 -5 0 5 10 15 20 0 5 10 15 u, degrees a, degrees Figure 5.- Effect of 0.010 slot location an
40、d shape on longitudinal characteristics. . 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4 CL CD 1.4 1.2 1.0 .a .6 .4 *2 0 0 5 10 20 0 5 10 a, aegrees a, degrees Figure 6.- Comparison of longitudinal characteristics between various size slots, lo
41、cated on the wing, and basic wing configurations. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. 0 1C i 20 0 10 a, degrees 3. dr-rccc Figure 7.- Comparison between fence spoilers on the flap and basic wing configuration. Provided by IHSNot for Res
42、aleNo reproduction or networking permitted without license from IHS-,-,- 1.4 1.2 CL CD 1.0 .8 .6 .4 .2 0 -G -A -B 3 0“ 0“ 3 0“ - 0 0 -5 0 5 10 15 20 0 5 10 a, degrees a, degrees .ler Figure 8.- Comparison between fence spoilers at the 68-percent chord line and basic configuration. CL w Provided by I
43、HSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-l.h 1.2 CL 1.0 .9 Slot Spoiler Configuration width height . . . . . . . . . . . . . . . . . . . . . . . . . . LZLL 0 15 0 10 1:, 20 0 5 10 a, degrees a, degrees Figure 9.- Comparison of longitudinal characteristics
44、between fence spoiler at the 30-percent chord line, a 0.039 slot on the flap; and the basic configuration. . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WASHINGTON, D. C. 20546 OFFICIAL BUSINESS FIRST
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