1、.-WIND-TUNNEL INVESTIGATION OF A FOWLER FLAP AND SPOILER FOR AN ADVANCED GENERAL AVIATION WING I I John We Puulson, Jr. Luqley Reseurch Center Humpton, Vu. 23665 1 - 1 NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WASHINGTON, D. C. JUNE 1976 Provided by IHSNot for ResaleNo reproduction or networking
2、 permitted without license from IHS-,-,-TECH LIBRARY KAFB, NM - 1. Report No. 2. Government Accession No. 3. Recipients Catalog No. NASA TN D-8236 4. Title and Subtitle I June 1976WIND-TUNNEL INVESTIGATION OF A FOWLER FLAP AND 6. Performing Organization Code SPOILER FOR AN ADVANCED GENERAL AVIATION
3、WING I 7. Author(s) 8. Performing Organization Report No. John W. Paulson, Jr. L-10736 10. Work Unit No. 9. Performing Organization Name and Address 505-10-11 -03 NASA Langley Research Center 11. Contract or Grant No. Hampton, Va. 23665 13. Type of Report and Period Covered 12. Sponsoring Agency Nam
4、e and Address Technical Note National Aeronautics and Space Administration 14. Sponsoring Agency Code Washington, D.C. 20546 16. Abstract An investigation has been conducted in the Langley Research Center V/STOL tunnel to determine the effects of adding a Fowler flap and spoiler to an advanced gener
5、al aviation wing. The wing was tested without fuselage or empennage and was fitted with approximately three quarter-span Fowler flaps and half -span spoilers. The spoilers were hinged at the 70-percent chord point and vented when the .flaps were deflected. Static longitudinal and lateral aerody nami
6、c data were obtained over an angle-of-attack range of -80 to 220 for various flap deflec tions and positions, spoiler geometries, and vent-lip geometries. Lateral characteristics indicate that the spoilers are generally adequate for lateral con trol. However, the spoilers do have a region of low eff
7、ectiveness when deflected less than 100 or 15O, especially when the flaps are deflected 30 or 40. In general, the spoiler effective ness increases with increasing angle of attack, increases with increasing flap deflections, and is influenced by vent-lip geometry. In addition, the data show that some
8、 two-dimensional effects on spoiler effectiveness are reduced in the three-dimensional case. Results also indi cate the expected significant increase in lift coefficient as the Fowler flaps are deflected; when the flap was fully deflected, the maximum wing lift coefficient was increased about 96 per
9、cent. 17. Key-Words (Suggested by Authoris) 1 18. Distribution Statement Lateral control Unclassified - Unlimited Spoilers Fowler flaps General aviation Subject Category 08 -. For Sale by the National Technical Information Service, Springfield, Virginia 22161 Provided by IHSNot for ResaleNo reproduc
10、tion or networking permitted without license from IHS-,-,-WIND-TUNNEL INVESTIGATION OF A FOWLER FLAP AND SPOILER FOR AN ADVANCED GENERAL AVIATION WING John W. Paulson, Jr. Langley Research Center SUMMARY An investigation has been conducted in the Langley Research Center V/STOL tunnel to determine th
11、e effects of adding a Fowler flap and spoiler to an advanced general avia tion wing. The wing was tested without fuselage or empennage and was fitted with approx imately three -quarter -span Fowler flaps and half -span spoilers. The spoilers were hinged at the 70-percent chord point and vented when
12、the flaps were deflected. Static longitudinal and lateral aerodynamic data were obtained over an angle-of-attack range of -8O to 22O for various flap deflections and positions, spoiler geometries, and vent-lip geometries. Lateral characteristics indicate that the spoilers are generally adequate for
13、lat eral control. However, the spoilers do have a region of low effectiveness when deflected less than loo or 15O, especially when the flaps are deflected 30 or 400. In general, the spoiler effectiveness increases with increasing angle of attack, increases with increas ing flap deflections, and is i
14、nfluenced by vent-lip geometry. In addition, the data show that some two-dimensional effects on spoiler effectiveness are reduced in the three-dimensional case. Results also indicate the expected significant increase in lift coeffi cient as the Fowler flaps are deflected; when the flap was fully def
15、lected, the maximum wing lift coefficient was increased about 96 percent. INTRODUCTION The development of new, thick, high-lift airfoil sections has had a profound effect on the general aviation community because these sections offer the possibility of improved performance on several new light aircr
16、aft designs. These airfoils provide higher maxi mum lift coefficients than the conventional 64-Series airfoils used on many general avia tion aircraft. This increase in maximum lift coefficient allows the use of a smaller, more highly loaded wing with less wetted area. These developments can increas
17、e cruise performance and improve ride quality. The increased thickness of these airfoils also provides the opportunity for wing structural weight savings. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-With an appropriate high-lift device such as a
18、full-span Fowler flap, further reduc tions in wing area may be achieved, and the desirable low landing speeds of typical light aircraft can be maintained. Full-span flaps, however, generally preclude the use of con ventional ailerons, and an alternate method of lateral control is needed. One such me
19、thod would use partial span spoilers (also known as slot-lip ailerons). Several airplanes which use Fowler flaps with the advanced airfoils are already in either the design stage or early flight-test stage of development. (See ref. 1.) Some of these airplanes use the 17 percent-thick General-Aviatio
20、n (Whitcomb)-1 airfoil usually referred to as the GA(W)-1. (See refs. 2 and 3.) One particular aircraft which uses this airfoil is the Advanced Tech nology light twin (ATLIT). (See ref. 1.) This aircraft uses nearly full-span Fowler flaps for low-speed performance and half -span spoilers for lateral
21、 control. These spoilers are vented when the flaps are extended and unvented when the flaps are retracted. Before the original flight of the ATLIT, there was concern about the effectiveness of the spoilers at small deflections when the flaps were deflected 40 because of two-dimensional data (refs. 4
22、 and 5). The data of reference 4 indicated that the spoilers had a region of very low effectiveness when deflected less than loo or 15O. In addition, there was control reversal under certain conditions. If a small left spoiler deflection was given -c in an effort to produce a negative (left wing dow
23、n) rolling moment, the result was actually a positive (right wing down) rolling moment. This investigation was undertaken to deter -mine to what extent, if any, these two-dimensional effects were ppesent on a three-%. .dimensional wing. .t The investigation was conducted in the Langley V/STOL tunnel
24、 by using a rectangu lar wing with Fowler flap and spoilers. Static forces and moments were obtained for the wing with various flap deflections and positions, spoiler deflections, spoiler cross -section geometries, and vent-lip geometries. SYMBOLS The data are presented in the stability-axis system
25、shown in figure 1. The model moment center was 25 percent of the wing chord. All measurements and calculations . were made in U.S. Customary Units; however, all values contained in this study are given in both SI and U.S. Customary Units. (See ref. 6.) b wing span (without subscript), span of flap,
26、or vented spoiler (with subscript), m (ft) Drag CD drag coefficient, q,s 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-CL lift coefficient, -Lift qcos Cl rolling -moment coefficient, Cm pitching -moment coefficient, Cn yawing-moment coefficient,
27、Rolling moment q,Sb Pitching moment q,se Yawing moment q,Sb CY side-force coefficient, Side force %as C wing chord, m (ft) -C mean aerodynamic chord, m (ft) P roll rate, rad/sec pb/2V, wing-tip helix angle, rad (see appendix) g, free-stream dynamic pressure, Pa (lbf/ft2) R radius, percent of wing ch
28、ord S wing area, m2 (ft2) v, free-stream velocity, m/sec (ft/sec) X longitudinal dimension (see fig. 1) X/C longitudinal distance from wing leading edge with respect to mean aerodynamic chord Y lateral dimension (see fig. 1) 3 Provided by IHSNot for ResaleNo reproduction or networking permitted with
29、out license from IHS-,-,-z CY 6 Subscripts : f max S vertical dimension (see fig. 1) angle of attack of model reference line, positive nose up (fig. l), deg deflection of flap or spoiler (fig. 3), deg flap maximum spoiler APPARATUS AND PROCEDURES This investigation was conducted in the Langley V/STO
30、L tunnel in support of the ATLIT aircraft program to determine the general characteristics of an ATLIT-type Fowler flap and spoiler lateral-control system. An existing aspect-ratio-8.98 rectangular wing with the GA(W) -1 airfoil section was modified to accept the Fowler flap and spoiler as shown in
31、figures 2 and 3(a). The wind-tunnel model was not intended to represent the ATLIT tapered wing exactly but rather to be a general representation of the ATLIT Fowler flap and spoiler system. Tables I and 11 give the coordinates of the GA(W)-1 wing section and flap section, respectively. The wing had
32、a span of 4.01 m (13.16 ft), a chord of 0.45 m (1.46 ft), and an area of 1.79 m2 (19.31 ft2). When the flaps were fully deflected, the wing area was increased by 17 percent to 2.10 m2 (22.59 ft2). The wing root was at an inci dence of 20 and the wing was linearly twisted to a tip incidence of Oo. Fo
33、r this investiga tion, the model reference line was defined to be the wing-tip chord line. The Fowler flaps were made in four sections on each wing panel (fig. 2) but were always deflected as a unit. Each flap section was mounted on brackets to allow deflections of 00, 100, 200, 300, and 400. Table
34、Ill shows a complete listing of flap deflection and position as well as the spoiler and vent-lip geometries for this investigation. Figure 3(b) shows the flap overlap and gap dimensions corresponding to the various flap deflections and positions. The flap chord was 30 percent of the wing chord and t
35、he flap span ratio bf/b/2 was 0.764. The spoilers were made in four sections for the left wing panel only. (See fig. 2.) In order to simulate the ATLIT spoiler-span wing-span ratio, only the three outboard sections were deflected during the investigation; the inboard section (spoiler section a) 4 Pr
36、ovided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-remained sealed at all times. The three operative spoiler sections (b, cy and d) had a span ratio bs/b/2 of 0.572 and were hinged at x/e = 0.70. (See figs. 2 and 3(a).) The hinge line was offset 0.015e fo
37、rward of the leading edge of the spoiler so that the trailing edge of the spoilers was located at x/e = 0.80 when 6s = 00. This offset hinge line allowed a gap to open between the wing upper surface and the spoiler leading edge as the spoiler was deflected. (See fig. 4.) Each spoiler section was rem
38、ovable and could be re placed with one of three spoiler cross-section geometries (also shown in fig. 4). The vent lip (the downstream lip of the spoiler vent) as well as the spoiler geometry was varied during the test as shown in figure 5. The model installation in the V/STOL tunnel is shown in figu
39、res 6 and 7. Most of the investigation time was concentrated en the cases with 400 flap deflection. At 400 flap deflection, the control effectiveness problem areas which were indicated in the two-dimensional data of reference 4 were examined over a spoiler-deflection range of 00 to 450 for different
40、 combinations of spoiler cross -section geometry and vent -lip geometry. Lower flap deflections were tested to obtain longitudinal and lateral data, but these tests were run by using only the triangular backed spoiler (spoiler B) and the large radius vent lip. Angle of attack ranged from -8O to wing
41、 stall. Most of the data were obtained at a dynamic pressure of 1.44 kPa (30 lbf/ft2); how ever, because of hardware constraints, some data were obtained at a dynamic pressure of 0.48 kPa (10 lbf/ft2). Whenever the dynamic pressure was lowered to 0.48 kPa (10 lbf/ft2), a single pair of runs was made
42、 with the identical configuration at both the high and low dynamic pressures to establish Reynolds number effects. The Reynolds numbers corresponding to these dynamic pressures are 1.49 Y lo6 and 0.85 X 106, respectively. It should be noted that at the lowest dynamic pressure, the Reynolds number is
43、 subcritical over a large portion of the wing chord. Transition was fixed at 2.24 cm (0.88 in.) downstream from the leading edge for the upper surface and 4.32 cm (1.70 in.) on the lower surface (ref. 7). Data were corrected for tunnel wall effects of reference 8; no other corrections were applied.
44、PRESENTATION OF RESULTS The data of this investigation have been reduced to coefficient form and are pre sented in the following figures: Figure Effects of flap position and deflection on spoiler B characteristics . . . . . . . . 8 Effects of vent-lip geometry on spoiler B characteristics. . . . . .
45、 . . . . . . . 9 and 10 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Figure Effects of vent -lip geometry on spoiler C characteristics . 11 Spoiler A characteristics 12 Effects of sequential deflection of spoiler B elements b, c, and d . 13 Effe
46、cts of dynamic pressure 14 .Effects of flap positions and deflections on wing longitudinal characteristics . 15 Rolling moments generated by deflection of spoilers B, C, and A . 16 to 19 DISCUSSION The effects of spoiler deflection, with various flap positions, cross-section geome tries, and vent -l
47、ip geometries, on the longitudinal and lateral characteristics of the wing are presented in figures 8 to 12. It may be seen from these data (particularly CL and C2 plotted against a) that the vented spoiler effectiveness is very low when deflected less than 100 to 150. In figure 13, the sequential s
48、poiler deflections (sequences 1 and 2) confirm the trends of the previous data; the spoiler effectiveness remains low until the spoiler elements are deflected 150. The data of figures 8 to 13 were used to construct the lift, drag, and pitching-moment curves of figure 15 with 6, = 0 and the rolling-m
49、oment curves of figures 16 to 18. The effects of Reynolds number are presented in figure 14. The effects on the lon gitudinal data were small with the typical increase in CL,at the higher Reynolds number. The effects on the lateral data were somewhat inconsistent but generally not large. Longitudinal Characteristics The data of figure 15(a) show the longitudinal characteris
