1、 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-6 Kenneth W. Goodson L-7639 10. Work Unit No. I 760-73-01 2. Sponsoring Agency Name and Address National Aeronautics and Space Administration Washington, D.C. 20546 9. Performing Organization Name and
2、Address NASA Langley Research Center 11. Contract or Grant No. Hampton, Va. 23365 13. Type of Report and Period Covered Technical Memorandum 14. Sponsoring Agency Code Super critical wing Low-speed aerodynamic characteristics Pressure data 6. Abstract Tests were conducted in the Langley high-speed 7
3、- by 10-foot tunnel on a rectangular aspect-ratio-6 wing which had a supercritical airfoil section. The wing was fitted with several high-1st flap systems: plain flap, single-slotted flap, and a double-slotted flap, in addition to the slot which exists in this early version of the supercritical airf
4、oil. The plain and single -slotted flaps were 40-percent chord. The double-slotted flap consisted of the 40-percent-chord plain flap with a 15-percent chord vane. All the flap configurations were tested with a wing-leading-edge slat set at various nosedown angles (Oo to 60) with respect to the wing-
5、chord line. The flaps could be set at angles from 30 to 60. Pressure distributions were measured on each segment of the wing and flap at a midsemispan station. Tests were made over an angle-of-attack range of -4O to 20. Agencies and Their Contractors Only SCNEDUEE - DECLASS - _ 17. Key Words (Sugges
6、ted by Authorls) ) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-LOW-SPEED AERODYNAMIC CHARACTERISTICS OF A RECTANGULAR, ASPECT-RATIO-6, SLOTTED SUPERCRITICAL AIRFOIL WING HAVING SEVERAL HIGH-LIFT FLAP SYSTEMS* By Kenneth W. Goodson Langley Researc
7、h Center SUMMARY Tests were conduct d in the Langley high-speed 7- by 10-foot tunnel on a rectangu- lar aspect-ratio-6 wing which had a slotted supercritical airfoil section. The wing was fitted with several high-lift flap systems: plain flap, single-slotted flap, and a double- slotted flap, in addi
8、tion to the slot which exists in this early version of the supercritical airfoil. The plain and single-slotted flaps were 40 percent chord. The double-slotted flap consisted of the 40-percent-chord plain flap with a 15-percent-chord vane. All three flap configurations were tested with a wing leading
9、-edge slat set at various nosedown angles (Oo to 60) with respect to the wing-chord line, Tests were made over an angle- of-attack range of -4 to 20. The flaps could be set at angles from 30 to 60, except for the double-slotted flap which was tested up to 70 deflection. Pressure distributions were m
10、easured on each segment of the wing and flap at a midsemispan station. The pressure data obtained on this model are believed to represent the two-dimensional data closely since the aspect ratio is relatively large and the wing is rectangular in planform. The results show, as expected, that a leading
11、-edge slat or other device is essential if high-lift capability is to be achieved. The maximum lift coefficient of the flapped system varies from about 2.85 or the plain flap to about 3.65 for the double-slotted flap for flap angles of about 50 with the leading-edge slat at about 40. Sample pressure
12、 distributions showing overall trends are presented for the basic wing and for each type of flap. The tests were made primarily at a Reynolds number of approximately 1.05 X lo6, INTRODUCTION In recent years, interest has been focused on improving the aerodynamic character - istics of aircraft in the
13、 high subsonic and transonic speed range. Aircraft utilizing con- ventiondl high-speed airfoil sections are penalized at these high speeds because of the *Title, Unclassified. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-drag rise associated with
14、shock-induced separation which results in high thrust require - ments. Recent high-speed wind-tunnel work (ref. 1) by Richard Whitcomb and associates has shown that special contoured airfoils (supercritical airfoils) provide considerable improvement in the lift and drag characteristics at transonic
15、speeds. These aircraft, however, must be able to land and take-off from reasonable length runways without undue penalty. For this reason the present investigation was undertaken to study the low-speed aerodynamic characteristics of several high-lift flap systems on an early slotted version of the su
16、percritical wing. Subsequent tests at high transonic speeds on supercritical air- foils have shown that the slot in the airfoil is not needed. The investigation was conducted in the Langley high-speed 7- by 10-foot tunnel on a rectangular aspect -I-atio-6, supercritical airfoil wing which was fitted
17、 with several high-lift flap systems: a plain flap, a single-slotted flap, and a double-slotted-flap. Each flap configuration was tested with and without a leading-edge slat. The flap systems included the slot which exists near the trailing portion of the basic supercritical airfoil. Pressures were
18、measured on each segment of the wing-flap system at the midsemispan station. SYMBOLS AND COEFFICIENTS The measurements of this investigation are presented in the International System of Units (SI), the U.S. Customary Units being indicated in parentheses. The measure- ments and calculations were made
19、 in the U.S. Customary Units. Details concerning the use of SI units, together with physical constants and conversion factors, are presented in reference 2. (Also, see appendix.) The positive directions of forces, moments, and angles are indicated in figure 1. The data are presented about the stabil
20、ity axes with moments presented about the quarter chord of the mean geometric chord. A aspect ratio a0 theoretical two-dimensional lift -curve slope b wing span, meters (ft) C wing chord, meters (ft) c1 section of basic wing ahead of slot (0.858) and section of basic wing ahead of various flap confi
21、gurations (0.75c), meters (ft) (see table 11) 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-c2 c3 c4 c5 CD cD, o CL Cm Cm, o CP e pl pm qm R S vm X chord of flap leading section, meters (ft) (see table 11) chord of basic airfoil segment aft of sl
22、ot; also trailing section of flaps aft of slot (same as for basic wing), meters (ft) (see table 11) chord of leading-edge slat, meters (ft) (see table 11) chord of flap vane, meters (ft) (see table 11) drag coefficient, Drag - qms profile drag coefficient lift coefficient, - Lift qms three -dimensio
23、nal lift -curve slope pitching-moment coefficient, pitching-moment coefficient at zero lift coefficient (a = 0) Pitching moment q,se - prm qm pressure coefficient, Oswalds wing efficiency factor, CL2 * ( cD - cD, 0) local static pressure, newtons/meter2 (lb/ft2) free -stream static pressure, newtons
24、/meter2 (lb/ft2) free - str eam dynamic pres sure, newtons /meter (lb/ft 2, radius, cm (in.) wing area, meter2 (ft2) free-stream velocity, m/sec (ft/sec) distance along chord of selected wing or flap element (see tables I to IV), meters (ft) 3 Provided by IHSNot for ResaleNo reproduction or networki
25、ng permitted without license from IHS-,-,-lower ordinate upper ordinate y2 YU a angle of attack of wing chord line (also of fuselage center line), deg flap deflection referenced to wing-chord line, deg 6f 6s leading-edge slat deflection with respect to wing-chord line, deg 6, vane deflection of doub
26、le-slotted flap with respect to wing-chord plane, deg Subscript: max maximum MODEL AND APPARATUS A drawing of the rectangular aspect-ratio-6, supercritical airfoil wing model is presented in figure 2. The basic supercritical wing was fitted with several high-lift flap systems, one of which is also s
27、hown in the second end view of figure 2. The high-lift flap systems were formed by modifying the basic supercritical airfoil section to form a plain flap, a single-slotted flap, and a double-slotted flap. The plain and single-slotted flaps consisted of the aft 40 percent of the basic airfoil, the 0.
28、375-chord nose of the flap being rounded off to conform to the leading edge of a modified 4415 airfoil to fit into the basic airfoil ordinates at the 0.75-chord station. The double-slotted flap was formed by adding a 0.15-chord vane (St. Cyr 156 airfoil) to the front of the plain 40-percent-chord fl
29、ap. Coordinates for the basic supercritical airfoil are shown in table I. The details of each flap configuration and the coordinates of the various components are shown in figure 3 and table II. The flap angles could be set at the angles indicated in figure 3 through the use of fixed brackets. The w
30、ing was also fitted with a 15-percent-chord leading-edge slat having a St. Cyr 156 airfoil. (See fig. 3 and table II.) The model had a minimum sized body to house the strain-gage balance, angle-of- attack indicator, and the pressure-measuring scanner valves. The basic wing was con- structed of solid
31、 aluminum, whereas the body consisted of a 0.32-cm-thick (1/8-in.) fiber -glass-resin shell attached to the balance mounting block. The various components of the flaps and slat were constructed of steel. Each component of the wing-flap-slot sys- tem had pressure orifice tubes installed at the midsem
32、ispan station of the left wing panel for measuring pressure contours through the use of scanner valve transducers. The 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-chordwise locations of the pressure orifices are shown in tables 111 and IV. The
33、model was mounted on a six-component strain-gage-balance sting support system. Photographs of the model mounted in the Langley high-speed 7- by 10-foot tunnel are shown in figure 4. TESTS AND CORRECTIONS The investigation was conducted in the Langley high-speed 7- by 10-foot tunnel. Most of the test
34、s were conducted at a dynamic pressure of 1915 newtons/meter (40 lb/ft2). A 0.25-cm-wide (0.1-in.) strip of No. 60 carborundum (33 grains per cm or 85 grains per inch) was located on the upper surface of the wing and slat leading edges at the 0.06-chord position to fix transition and to improve the
35、stall characteristics. The transition strips were used for all tests. The basic wing was tested through a Reynolds number range from 0.70 X 106 to 2.40 X 106. All the flap tests were made at a Reynolds number of 1.05 X lo6 at a dynamic pressure of 40 lb/ft2 and a Mach number of approxi- mately 0.17.
36、 The Reynolds numbers were based on the wing geometric chord of 30.48 cm (12 in.). double-slotted flap was tested at 50, 60, and 70. The three flap configurations were tested with a leading-edge slat at various nosedown angles (6s = 30, 40, 50, and 60) measured with respect to the wing-chord line. T
37、he flaps were also tested with the basic airfoil slot sealed with transparent cellophane tape. Tests were made over an angle-of- attack range of -4O to 22. Pressure distributions were measured on each segment of the wing and flap at the midsemispan station of the left wing panel. The plain and singl
38、e-slotted flaps were tested at 30, 40, and 50, whereas the Jet-boundary corrections (ref. 3) and blockage corrections (ref. 4) were applied to the measured force and moment data. The drag data were also corrected for base pres- sure measured on the small body. PRESENTATION OF RESULTS The basic-wing
39、longitudinal aerodynamic characteristics are presented in figure 5. The aerodynamic characteristics of the flap configurations with and without the leading- edge slat are presented in figures 6, 7, and 8 for the plain, single-slotted, and double- slotted flaps, respectively. These basic data have be
40、en rearranged to show a direct comparison of the various flaps at a given flap deflection and slat deflection as shown in figure 9. Results showing the effect of sealing the slot of the basic airfoil is presented in figures 10 to 12. A plot showing the best flap-slat combination for each flap config
41、ura- tion is shown in figure 13. Figure 14 compares the chordwise pressure distribution of the various flap configurations for a deflection of 50 with and without the leading-edge slat at several angles of attack. 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license
42、 from IHS-,-,-DISCUSSION Basic Wing Low-speed results for the basic rectangular aspect-ratio-6 slotted supercritical wing show a lift-curve slope of about 0.082 per degree or 4.70 per radian. (See fig. 5.) By correcting this value to infinite aspect ratio by use of the equation (from ref. 5) a two-d
43、imensional value of 6.64 per radian can be obtained which is essentially the theo- retical value for an airfoil of this thickness (13 percent). The data of figure 5 show a reduction in lift coefficient (at stall) with increase in Reynolds number, which is contrary to that normally expected at low sp
44、eeds. It is prob- able that at the higher Reynolds numbers, compressibility effects coupled with the thick- ness of the present wing (13-percent chord) and the leading-edge airfoil contour could cause local separation that reduces the maximum lift coefficient. Note the negative angle of attack at ze
45、ro lift coefficient and also note the negative Cm,o resulting from the shape (camber) of the supercritical airfoil. The merits of the basic slotted supercritical airfoil at high subcritical Mach num- bers as substantiated by two-dimensional pressure measurements are presented in reference 1. Flapped
46、 Wing The present flap investigation was undertaken to see whether there were any par- ticular problems associated with obtaining high lift on the supercritical airfoil configura- tion. It was felt that maximum lift coefficients historically obtained on various types of flap systems should also be o
47、btainable with the supercritical airfoil. Comparison of the basic flap data of figures 6, 7, and 8 shows that anticipated values of lift coefficient based on results of conventional airfoil flap data were, in fact, achieved. These data show that the maximum lift coefficient for the 40-percent-chord
48、flaps varied from 2.85 for the plain-flap configuration to about CL,max = 3.70 for the double-slotted-flap configuration, provided a leading-edge slat was used to prevent early wing stall. The data show that for very high lift the leading-edge slat is an essential component of the flap system in ord
49、er to direct the large upwash at the leading edge properly. Comparison of different leading- edge slat deflection angles indicates that there is an optimum angle above or below which separation will occur from either the upper or lower surface of the slat. Separation 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from
