1、E $ II I- k .$ .),-, 7 CLASSIFIED DOCUMENT This material contains information affecting the National Defense of the United States withln the me in addition, the sections remain unstalled over a large range of angle of attack. The flap-deflection angles were measured in the plane of the flap ends; th
2、at is, normalto a line swept 36.77. Filler blocks of balsa wood were provided to block the slots in the flap with 0.300cf vane when an extended plain flap is simulated (fig. 2(a). The fuselage (fig. 1) was a cylinder with an ogival nose and a ratio of diameter to wing span of 0.12. A large aluminum
3、plate (fig. 3) was used to approximate the effect of the proximity of the fuselage to the inboard end of the blocked flap. The plate was adjustable over the part of the span of the wing inboard of the flap. The model with the flap span extended inboard to the fuselage is shown in figure 4. This exte
4、n- sion, which was made of sheet metal and had no slots, was used for some tests with the double slotted flap and with the blocked flap. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I i I I i I I I I I l! , NACA RM 5602 5 The unmodified wing was s
5、olid aluminum. The trailing-edge modifi- cation described herein and the flap were made of mahogany reinforced with an aluminum plate extending to the trailing edge of the wing. The fuselage was constructed of laminated mahogany. Both vanes were machined from aluminum. The larger of the two vanes wa
6、s supported at each end, but the smaller vane required a center support in addition to the end supports. The semispan model was mounted vertically in the Langley 300 MPH 7- by lo-foot tunnel. The root chordof the model was adjacent to the ceiling of the tunnel, which served as a reflection plane. A
7、small clearance was maintained between the model and the tunnel ceiling so that no part of the model came into contact with the tunnel structure. The fuselage minimized the effect of spanwise air flow over the model through this clearance hole; For tests with the fuselage removed, the effect of span
8、wise air flow was minimized by a l/16-inch-thick end plate which projected about 1 inch above the wing surface at the root of the wing. TESTS AND CORRECTIONS Description of Tests All tests were made in the Langley 300 MPH 7- by lo-foot tunnel. Data were obtained through an angle-of-attack range of -
9、6 to 26 for all configurations. The flap-deflection range for the double-slotted- flap tests was approximately 41 to 90 for the flap and 0.500cf vane and 41 to 71 for the flap and 0.266cf vane. The tests in general were performed at an average dynamic pressure of 25.4 pounds per square foot, which c
10、orresponds to a Mach number of 0.13 and a Reynolds number of 1.8 x 10 6 based on the mean aerodynamic chord of the wing. Tests over a range of Reynolds numbers were made with both double-slotted-flap designs at a flap deflection of about 60. The Reynolds number was changed by raising the tunnel velo
11、city from 45 miles per hour to about 200 miles per hour. Mach number effects in this speed range are considered negligible. The conditions for the variable Reynolds number tests are given in the following table: I Provided by IHSNot for ResaleNo reproduction or networking permitted without license f
12、rom IHS-,-,-NACA RM 5602 6.9 I Mach LLW - -mber Reynolds number I I 0.93 x 106 25.4 65.5 91.8 In addition to the tests of the double-slotted-flap configurations, tests of the flap and 0.500 vane were made with both slots blocked. Tests in which the large movable plate (fig. 3) was used to simulate t
13、he proximity of a fuselage to the inboard end of the flap with slots blocked were made at a flap deflection of about 60. Tests with the flap extended spanwise to the fuselage (fig. 4) were made at flap deflections of 70.7 with the double slotted flap and at 50.7 and 70.7 with the slots blocked. Corr
14、ections Jet-boundary corrections, determined by the method presented in reference 4, have been applied to the angle-of-attack and to the drag- coefficient values. Blocking corrections, to account for the constriction effects of the model and its wake, have also been applied to the test data by the m
15、ethod of reference 5. RZXXJLTS AND DISCUSSION Presentation of Results The basic longitudinal characteristics are presented for the wing- fuselage model with double slotted flaps in figure 5 and for the model with extended plain flaps in figure 6. The effects of the fuselage on the aerodynamic charac
16、teristics were obtained by comparison of the present data with the wing data of reference 1. Comparisons showing the effects of the fuselage on the aerodynamic characteristics of the plain wing in pitch are presented in figure 7, and on the variation of ACL with Ef for the wing with double slotted f
17、laps and with blocked flaps, in fig- ures 8 and 9, respectively. The results of tests to determine the effect of extending the span of the flaps inboard to the fuselage are given in figure 10 and are com- pared with the basic flap-effectiveness characteristics in figure 11. Provided by IHSNot for Re
18、saleNo reproduction or networking permitted without license from IHS-,-,- I I li 1; i i 1 I 1 I $ , NACA RM 5602 7 The characteristics of the flapped wing with a large plate used to simu- late the effect of fuselage proximity are shown in figures 12 andl3. The results of tests of the wing-fuselage m
19、odel at several Reynolds num- bers and with the double slotted flap deflected 60 are presented in figure 14, and the variation of incremental lift coefficient with Reynolds number is shown in figure 15 for a =.oO. Lift Characteristics Wing-fuselage model.- Basic wing-fuselage results at Ef = 0 (fig.
20、 5) show a lift-curve slope of 0.055 and a maximum lift coefficient of 1.03 at an angle of attack of 23O. Model with double slotted flaps.- The results for the model with double slotted flaps and with the large vane (fig. 5(a) show that a large lift-coefficient increment was obtained at a, = 0 by de
21、flecting the flaps. However, the stall of the flapped wing (at CL = 11) occurred at a much lower angle than the model with 6f = Oo (a, = 23O). Therefore, the resulting maximum lift coefficient for the flapped configuration was only about 0.2 greater than the maximum lift coefficient of 1.03 attained
22、 with Ef = 0. The maximum lift coefficient for the double slotted flaps with the small vane was 1.14 at Ef = 60.8, as is shown in figure 5(b). The results (also see fig. 8) indicate that increasing the vane size resulted in greater EL over the angle-of-attack and deflection range. At a = O“, the max
23、imum EL was 0.73 at Sf = 80.4 for the double slotted flap and large vane compared with 0.59 at Gf = 60.8 for the flap and small vane. The loss in lift increment was very abrupt for either flap and vane combination at deflections above the deflections for maximum XL. The higher effectiveness of the f
24、lap and large vane is mainly the result of the ability of the vane to control the flow over the flap to higher deflection angles and to a lesser degree, its greater area. Model with slots blocked.- For comparison with the double slotted flap, the characteristics of an extended plain flap were obtain
25、ed. The extended plain flap was simulated by blocking both slots of the double slotted flap as shown in figure 2(a) and will be referred to as the blocked flap. The results (fig. 6) show a similar variation of lift coefficient with angle of attack at 6f = 40.70 for the blocked flap and for the doubl
26、e slotted flap. At the higher flap deflections tested, the lift curves for the blocked flap are nonlinear and the increase in lift increment gained by deflecting the flaps to 50.7 and higher is very small, especially in the range of angle of attack from 2 to 7. Provided by IHSNot for ResaleNo reprod
27、uction or networking permitted without license from IHS-,-,-8 - NACA RM 5602 Comparison of figures 5 and 6 shows that the result of blocking the slots was a considerably lower value of fXL for flap deflection above 40.7. This result is also shown in figure Il. Effect of the fuselage.- Plain-wing res
28、ults of reference 1 are com- pared with wing-fuselage-model results in figure 7. Adding the fuselage .to the wing increased the lift-curve slope from 0.053 to 0.055 at low angles of attack and increased maximum lift slightly. The effect of the fuselage on the lift of the wing with flaps deflected wa
29、s considerably greater as shown in figure 8. Adding the fuse- lage to the wing with double slotted flaps increased ACL by an average of 0.06 over the deflection range at ry, = -00 and somewhat less at a = 10. Maximum lift coefficient of the wing-fuselage model with double slotted flaps and 0.500cf v
30、ane was 1.23 as compared with the value 1.17 given in reference 1 for the configuration without a fuselage. When the slots were blocked (see fig. 9) the fuselage effects reduced the lift increment at flap deflections greater than 40.7. In reference 1, in fuselage-off tests, the existence of a vortex
31、-type flow over the inboard end of the flap was given as a possible explanation of the ability of the flap with slots blocked to maintain effectiveness to high flap- deflection angles (Sf = 70“). Observation of the flow by means of a tuft on a probe indicated that a vortex did not form after the fus
32、elage was added and, therefore, the flap was not effective at the higher angles. A further change in the conditions at the inboard end of the flap was made by extending the span of the flap inboard to intersect the fuse- lage. The results of the tests of the double slotted flap and the blocked flap,
33、 each with inboard span extension, are presented in figure 10. The effect on the double slotted flap (figs. ?(a), 10, and 11) and the blocked flap (figs. 6, 10, and 11) was a general reduction in lift over the angle- of-attack range. Observation of tufts indicated that the flow over the flap extensi
34、on was very rough for both flap conditions. Also, in the case of the double slotted flap, the inboard flap extension increased the spanwise flow on the lower surface of the wing. This disturbed flow, which was possibly further disturbed by the inboard flap-support bracket, entered the slots and caus
35、ed unsteady flow over the vane and flap and consequently a loss in lift. Tests of the blocked flap were also made with the fuselage replaced by a large plate (fig. 3) which could be translated in a spanwise direc- tion. The results of these tests (see fig. 12) are cross-plotted for various angles of
36、 attack in figure 13 to show the variation of lift coef- ficient with the ratio of plate distance from the plane of symmetry to fuselage radius, d/R. Fuselage-off and fuselage-on test results are plotted at 0 and l.Od/R, respectively. The plate began to influence the wing lift at d/R = 0.7. Further
37、outboard movement of the plate generally Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA RM 5602 9 decreased the lift for a given angle of attack and at the maximum d/R tested, 0.93, the plate caused a somewhat greater loss in lift than was caus
38、ed by adding the fuselage. Observation of the flow with a tuft indicated that when the fuselage was on or the plate was located near the flap (d/R 0.8) there was no vortex, as had been the case for the wing alone, to hold the flow over the flap and therefore the lift was reduced. Pitching-Moment Cha
39、racteristics Pitching-moment characteristics for the wing-fuselage model, with 6-f = O“, (fig. 7) indicated an increasingly stable variation of pitching moment with lift coefficient to CL = 0.7, where it became unstable. Comparison with the plain-wing results indicates generally similar pitching-mom
40、ent characteristics except that the addition of the fuselage to the plain wing caused about a l-percent forward shift in the aero- dynamic center to O.Z!, measured at CL = 0. Deflection of the double slotted flap with the fuselage on had much the same effects on the pitching-moment characteristics a
41、s were given in reference 1 for the wing. As shown in figure 5(a), the addition of the double slotted flap ( 0.500 vane resulted in small shifts of the aerodynamic center, a delay in the unstable break of the pitching-moment curve to CL c 1.0, and, for example, at Ef = 50.7, a Cm, ,increment of abou
42、t -0.15. Similar results are shown for the flap and o.266cf vane (fig. 5(b) and for the blocked flap (fig. 6). Drag Characteristics The addition of the fuselage to the plain wing resulted in an increase in minimum drag coefficient from 0.008 to 0.015. (See fig. 7.) Comparison of the drag results of
43、figure 5 with the results of ref- erence 1 indicated that the fuselage had a favorable effect on the maxi- mum L/D ratio for a given lift coefficient. At a lift coefficient of 1.1, adding the fuselage increased the L/D values from 3.9 to 4.6 for the flap and large vane and from 3.8 to 4.0 for the fl
44、ap and small vane. Effect of Reynolds Number The results of tests of the double slotted flaps over a range of Reynolds numbers from 0.93 X 106 to 3.35 x lo6 are given in figure 14. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-10 t NACA RM 5602 The
45、 flap deflection for these tests was about 60. A plot of ACL against Reynolds number is given in figure 15. These results indicate that the lift and pitching-moment characteristics of the double slotted flaps were only slightly affected by the variation of Reynolds number. Some increase in maximum C
46、L with Reynolds number and a corresponding delay of the unstable break in Cm,w to higher values of CL are shown. No correction was made to account for the change in the angle of zero lift of the wing with Sf = O“ shown in figure 14. This effect is attributed to tunnel characteristics. A definite red
47、uction in the drag is shown for lift coefficients in the range just below the stall. At a lift coefficient of 1.0, the lift-drag ratio for the flap and either , vane increased from about 4.5 to 5.2 when the Reynolds number was increased. CONCLUDING REMARKS A low-speed investigation has been made to
48、determine the effect of a fuselage on the longitudinal aerodynamic characteristics of a 45 swept- back wing equipped with 0.35-semispan double slotted flaps. Comparison is made with previously reported results on the wing alone to determine fuselage effects. The fuselage had a favorable effect on-th
49、e lift characteristics of the double slotted flap. However, the presence of the fuselage had an adverse effect on the lift characteristics of an extended plain flap. The double slotted flaps increased the lift with an increase in flap deflection up to a flap deflection of 80.4 for a flap which had a ratio of vane chord to flap chord of 0.500, and up to 60.8
