NASA-TN-D-217-1960 Low-speed investigation of static longitudinal and lateral stability characteristics of an airplane configuration with a highly tapered wing and with several bod.pdf

1、NASA TN D-217 TECHNICAL NOTE D - 217 LOW -SPEED INVESTIGATION OF STATIC LONGITUDINAL AND LATERAL STABILITY CHARACTERETICS OF A-N ALIRPLANE CONFIGURATION WITH A HIGHLY TAPERED WING AND WITH SEVERAL BODY AND TAIL ARRANGEMENTS By Paul G. Fournier Langley Research Center Langley Field, Va. NATIONAL AERO

2、NAUTICS AND SPACE ADlv4INISTRAT!ON WASHINGTON January 1960 (AASA-TN-D-2 17) LCL-hfEEC ICI1IGETICN CE N84-7 0462 51ASIC LCHGIXUCILCL AEC LAIEEPL STAEILIIY ChPiidCPEfiIEIICS I AN ZIKELAtI CCLIGUEATICN kJIii A tlXGtlL1 IEEEREG YIlG a81 LIlE SEVE6AL Unclas LCCY AAC lAlL ACBLLGELEATS (8AsA) 53 p 00/06 01

3、95748 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-1Y NATIONAL AERONAUTICS AND SPACE ADMINISTRATION -. . L 8 1 8 TECHNICAL NOTE D-217 LOW -SPEED INVESTIGATION OF STATIC LONGITUDINAL AND LATERAL STABILITY CHARACTERISTICS OF AN AIRPLANE COWIGURATION

4、 WITH A HIGHLY TAPERED WING AND WITH SEVERAL BODY AND TAIL ARRANGEMENTS By Paul G. Fournier A low-speed investigation was made in the Langley 300 MPH 7- by 10-foot tunnel of the static longitudinal and lateral stability charac- kristics of an airplane model with multiple bodies and of a conventional

5、 (single-fuselage) model in combination with a wing of aspect ratio 4. The wing had zero sweep at the 80-percent-chord line, a taper ratio of zero, and an NACA 65AOO4 airfoil section. Several tail arrange- ments were tested with the three-body configuration along with a conventional-tail arrangement

6、 for both models. The results indicate that the pitching-moment characteristics for the three-body model appear to bear about the same relation to height of the horizontal tail as that which has been well established by previous investigations of conven- tional (single-fuselage) configurations. It a

7、ppears that acceptable longitudinal stability can be obtained for both complete model configu- rations with the horizontal tail located in or near the wing-chord plane. The data show that for the multiple-body (three-body) model all tail-on configurations were directionally stable throughout the ang

8、le- of-attack range and were greatly improved over the conventional model configuration which was directionally unstable above an angle of attack of 20. The data also indicate that this improved directional sta- bility for the complete three-body model results from the fact that with the tail off th

9、e directional stability becomes positive at high angles of attack. 3 Super s ede s re cent ly de c las s if i ed NACA Re s ear c h Memorandum L 57A08 by Paul G. Fournier, 1957. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-2 The three-body arrangem

10、ent investigated herein was conceived as a possible means for alleviating the problems mentioned in the preceding paragraph while maintaining an arrangement that would appear to entail no serious compromise in high-speed performance capabilities. Consider- ation of essentially the same general philo

11、sophy, but with emphasis on the improvement of high-lift longitudinal stability, provided the basis for the investigation reported in reference 3. For the test model, the total body volume was divided equally among three separate bodies - one which extends forward of the wing in the plane of symnetr

12、y and two which extend rearward from the wing at outboard locations. The wing had an aspect ratio of 4, a taper ratio of zero, and zero sweep at the 0.80-chord line. The tests covered several configurations of tails attached to the outboard bodies. Static longitudinal and lateral stability character

13、is- tics for the various arrangements of the model were determined at low speeds. For comparison purposes, the wing of the investigation was also tested in a conventional fuselage and tail arrangement. COEFFICIENTS AND SYMBOLS The axis system used and the direction of positive forces, moments, and a

14、ngles are presented in figure 1. All moments of the basic data are referred to the quarter-chord point of the wing mean aerodynamic chord, and except for lift and drag all data are presented about the body axis. b wing span, ft drag coefficient, Draa lift coefficient, Lift cD qs cL qs - L I I INTROD

15、UCTION -1 The conventional arrangement of current high-speed airplane configu- rations, in which the total required volume is contained primarily within a single long slender body to which the stabilizing surfaces are also attached, imposes certain objectionable flight characteristics as well as som

16、e undesirable operational limitations. With such configurations directional stability has been difficult to maintain at high angles of attack (ref. l), whereas a considerable amount of directional stability is required to avoid serious divergence problems due to roll coupling in an airplane with a c

17、oncentration of mass along the body (ref. 2). Incompatibility of engine and armament operation, stores release, and speed-brake installation are also complications encountered with a single slender fuselage. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IH

18、S-,-,-I 3 ., .I cl Cm Cn CY CnB r, - C 2 9 S V U B P %/4 rolling-moment coefficient, Rolling moment pitching-moment coefficient, Pitching moment qSb qse yawing-moment lateral-force coefficient, Yawing moment coefficient, Lateral force (2s dC rolling moment due to sideslip, A, per deg aP dCn CjP yawi

19、ng moment due to sideslip, -, per deg lateral force due to sideslip, -, ac, per deg dB wing chord, ft wing mean aerodynamic chord, ft fuselage or body length, in. free-stream dynamic pressure, - pv2, lb/sq ft wing area, sq ft free - s tr eam velocity , ft/s e c angle of attack, deg angle of sideslip

20、, deg mass density of air, slugs/cu ft sweep of the quarter-chord line, deg 2 increment of CnP due to vertical tail (coxpete model data minus wing-fuselage data) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4 TESTS AND CORRECTIONS All tests were m

21、ade at a dynamic pressure of 45.85 pounds per square foot, which for average test condition corresponds to a Mach number of about 0.18 and a Reynolds number of 1.85 x 106 based on the wing mean aerodynamic chord of 1.479 feet. The present investigation consists of tests made to determine the low-spe

22、ed static longitudinal and lateral stability characteristics of a three-body model as compared with a conventional ( single-fuselage) model. 26O and 36O, depending on the configuration. The parameters C zP, Cry, and Cy were determined from tests at sideslip angles of +5O through- P out the angle-of-

23、attack range. The angle of attack, drag, and pitching moment with the horizontal tail on have been corrected for jet-boundary effects as well as for blockage effects on the dynamic pressure and drag coefficient in accordance with standard procedures. The angle-of-attack range was from approximately

24、-bo to between F ? a I Vertical buoyancy on the support strut, tunnel-airflow misalinement, and longitudinal pressure gradient have been accounted for in the com- putation of the data. These data have not been corrected for the tares caused by the model-support strut; however, tare tests of a comple

25、te model similar to the conventional model of the present investigation have indicated that tares corresponding to the lateral coefficients are small, that the correction to drag coefficient is about 0.009 at zero lift, and that the correction to pitching-moment coefficient is small and independent

26、of angle of attack through most of the range. It is felt that the tare corrections for the three-body model would be still smaller, inasmuch as there is no fuselage directly rearward of the model- support strut. MODEL AND APPARATUS The wing of the present investigation had an aspect ratio of 4, a ta

27、per ratio of zero, an NACA 65AOO4 airfoil section parallel to the plane of symmetry, and zero sweep at the 80-percent-chord line plate bonded with wood and machined to give the desired airfoil. = 28.800). The wing was fabricated from 0.5-inch aluminum-alloy (“e14 The three bodies as well as the sing

28、le fuselage were constructed The three-body model was constructed so that the total of mahogany. volume of the three bodies is the same as that of the single fuselage. For ease of construction all three bodies were made identical, the small fairing at the rear of the center body was added later. The

29、 ordinates .- Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-5 a3 rl a3 I 4 . of the single fuselage and of one body of the three-body model are pre- sented in tables I and 11, respectively. three-body model and the conventional model are presented

30、in figure 2. A photograph of the complete three-body model with a T-tail arrangement is shown in figure 3. Three-view drawings of the The horizontal- and vertical-tail surfaces used with the three-body model were made of 0.250-inch aluminum alloy, with rounded leading edges and tapered trailing edge

31、s. The horizontal-tail surface for the conven- tional model was of the same plan form as the wing but was made of 0.375-inch aluminum alloy with rounded leading edge and tapered trailing edge, whereas the vertical tail had an aspect ratio of 1.16 with an NACA 63AO09 airfoil section. Sketches of all

32、the tail arrangements used are presented in figure 4. than the one shown in figure 2(a) for the three-body model are presented in figures 2(c) and (d) . Details of additional tail assemblies other All horizontal tails had zero incidence. The three-body model was so constructed that the wing could be

33、 tested alone or with any symmetrical combination of the three bodies. The wing of this investigation was in a midwing position and was mounted so that moments and forces were measured about the quarter-chord of the wing mean aerodynamic chord. The model was mounted on a single support strut which i

34、n turn was attached to the mechanical-balance system of the Langley 300 MPH 7- by 10-foot tunnel. RESULTS AND DISCUSSION Presentation of Results The results of the present investigation are presented in figures 5 to 32. The longitudinal characteristics of the three-body model with various tail arran

35、gements are found in figures 5 to 14. A summary of the effect of the tail and body arrangements on the longitudinal charac- teristics is presented in figure 15. The variations of lateral data are shown in figures 16 to 32. Longitudinal Stability Characteristics The basic static longitudinal stabilit

36、y results presented in fig- ures ,5 to 14 represent a center-of-gravity location at the O.25c loca- tion. The static margin therefore varied somewhat with the different configurations. pitching-moment curves, the data in the summary plots (fig. 15) have In order to provide a more realistic compariso

37、n of the Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-6 been recomputed with respect to a center-of-gravity location such that 7 a static margin of 0.1OE is obtained for all configurations at zero lift. In general, figures l5(a) and (b) show that

38、the pitching-moment Characteristics of the three-body model are less favorable for the high- tail positions than for the case of the tail in the wing-chord plane. These results show very much the same trends with tail height as those established for conventional (single-fuselage) configurations (ref

39、. 4) and result primarily from the downwash characteristics behind the wing. Of the tails above the wing-chord plane, only the inverted V-tail (tail 6) showed no reduction in stability at high lift. The configuration with tail 6 provided the most nearly linear pitching-moment curves obtained in the

40、investigation (fig. 15); however, as is indicated in a subsequent section, the directional characteristics were rather poor for this : configuration. k c c Figures l5(c) and (d) show comparisons of the longitudinal stability of the three-body model with various tail arrangements and with the con- ra

41、tions. The results indicate that there are several possible tail arrangements with the three-body model that provide pitching-moment characteristics comparable to those of the single-fuselage model with a low tail. The three-body configurations with the cruciform tail (tail 1) or the modified crucif

42、orm tail with the inboard portion of the horizontal tail removed (tail 4) experienced rather rapid increases in stability at a = 7 and some reduction in stability above a 26O (fig. l5( c); however, these nonlinearities do not appear serious. wing-fuselage configurations shown in figure l5( d) indica

43、te that both the three-body model and the conventional single-fuselage model exhib- ited reasonably linear pitching-moment characteristics throughout the angle-of-attack range, and that the three-body model provided a some- what higher value of maximum lift coefficient. In general, it my be noted th

44、at for the tail incidence tested (OO), the three-body configu- ration (figs. l5(c) and (d) provided higher values of trim lift coef- ficient than the conventional configuration. ventional single-fuselage model for the complete and tail-off configu- c. The Lateral Stability Characteristics The effect

45、s on the static lateral stability derivatives of the addition of different arrangements of bodies to the wing with an aspect ratio of 4 are shown in figure 30. Although the wing alone has almost neutral directional stability, the addition of the conventional fuse- lage made the configuration directi

46、onally unstable throughout the angle- of-attack range with a region of very high instability between an angle of attack of 17 and of 25. three-body model were also directionally unstable; however, the large 6 The wing plus the center body of the ii Provided by IHSNot for ResaleNo reproduction or net

47、working permitted without license from IHS-,-,-7 curve for the conventional wing-fuselage configu- CnB dip found in the ration was absent. the conventional configuration and its absence for the configuration with the single center body is an indication of the adverse effect of the wing-induced sidew

48、ash on a fuselage afterbody as has been pointed out in reference 5. It is of interest to note that when the two outer bodies were added to the wing plus the center body the directional insta- bility at low angles of attack was about the same as for the conven- tional model; however, as the angle of

49、attack increased, the instability diminished for the three-body model. Above a = 15 the three-body model was stable with tail off. The presence of the region of high instability for A positive dihedral effect (-Czp) was noted for the wing alone and Both the conventional and the single-center-body configura- for the three-body configurations throughout the angle-of-attack r