1、RESEARCH MEMORANDUM THE LONGITUDINAL CHARACTERISTICS AT MACH NUMBERS UP TO 0.92 OF A CAMBERED AND TWISTED WING HAVING 40 OF - SWEEPBACK AND AN ASPECT FLAT10 OF 10 By George G. Edwards, Bruce E. Tinling, and Arthur C. Ackerman . Ames Aeronautical Laboratory CLASSlFRlYWlN CA%t!li-d am l NATIONAL ADVIS
2、ORY COMMITTEE FOR AERONAUTICS WASHINGTON September 15, 1952 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-LX , 1 NATIoRALADvIsORY COMMZMEE FCRAERONAUTICS RESEARCH MEM-UM . THELCNGITUDINBL CHARACTWISTICSAT MACHNUMBREM UP TO 0.92 SWEEPBACK AM) AN ASI
3、ECT RATIO OF 10 By George G. Edwards, Bruce E. TinUng, and Arthur C. Ackerman SUMMARY A swept-back Wang, in combination with a fuselage, of a type con- sidered suitable for long-range, high-speed airplaneghas been investi- gated in the Ames Xational methods but must be estimated on the basis of pa;
4、 2; .856 .875 -894 0912 1.001 1.001 1.002 1.002 1.003 1.004 1.005 1.006 1.007 l.OOB - - - 0.250 .598 .697 -794 .823 -850 .8-* NACA RM 5218 To establish the magnitude of possible aeroelastic effects, a static load test of the model ting was made to determine the twist due to bending. A lOCO-pound loa
5、d was dfstributed along the span according to the theoretical distribution calculated for incompressible flow for a lift coefficient of 1.0 by the method of reference 10. The results are presented in figure 5. For convenience, the loads on the wing per unit lift coefficient for various test conditio
6、ns sre also presented in this figure. Calculations from these data indicate that the twist due to bending, ACP, at the test condition where the aerodynamk load is greatest (?i - 0.25, R = ,COO,OOO) is about -2.20 (at the tip) per unit lift coefficient. The aerodynantlc data have not been corrected f
7、or the effects of this aeroelastic distortion. RESULTS . Results of tests of the wing alone are presented in figures 6 and 7. Figure 6 shows lift, drag, and pitching-moment data obtained at Reynolds nu all Reynolds numbers and occurred at a lift coefficfent of about 0.4 as shown by figure 22. An inc
8、rease of Reynolds number increased the lift-drag ratfo markedly at lift coefficients greater than 0.8. High speed.- As may be noted from the data of figure 7, the angle of attack for zero lift varied only slightly from its design value of -lo throughout the range of Mach numbers from 0.25 to 0.92. T
9、he pitching- moment coefficfent at zero lift, however, became slightly negative with increasing Mach number, attatiing a value of -0.015 at a mch number of 0.92. The reduction in longitudinal stability and abrupt increase in drag occurred at lower lift coeffFcients as the Mach number was increased.
10、l?he flow changes accompanying these stabflity and drag changes can be observed in the tuft photographs in figures 18(c) and 18(d). At a B in fact, they msde the wing-fuselage combination longitudinally stable at the stall. The three small fences (A, B, and C) did not substantially improve the pitc
11、hWg-moment characteristics at Mach numbers of 0.83 and 0.9. (See figs, 15(c) and 15(d).) The tuft photographs in figures 18(c) and 18(d) show that at these Mach numbers separation, probably induced by a shock wave, occurred considerably forward of the fences. Extended fences.- In order to interrupt
12、the spanwise flow within the separated region at high Mach numbers, the two outer fences were replaced with three fences extending well forward of the region of sepa- ration (fig. 3). These fences were placed at 50, 70, and 85 percent of the semispan. This fence configuration (denoted A, D, E, and F
13、 in the figures) proved to be very effective in improving the pitching-moment characteristics at the higher Mach numbers as shown in figures 15(c) and 15(d), as well as at a Mach number of 0.25 as shown in figures 15(a) and 15(b). The effects of this fence arrangement on the.aerodynamic characterist
14、ics of the wing alone at a Mach number of 0.165 (correspond- ing to a reasonable landrzlg speed) at a Reynolds number of ,OOO,OOO sxe shown in figures 16 and 17. These data show that addFtion of the four fences increased the lift coefficient at which a large decrease of statfc Provided by IHSNot for
15、 ResaleNo reproduction or networking permitted without license from IHS-,-,-RACA RM A32Fl8 17 longitudinal stability occurred by about 0.4, increased the maximum lift coefficient by about 0.2, and caused a large reduction in drag due to lift at lift coefficients above 1.0. It was not possible to con
16、duct a similar test of the wing-fuselage co:EZ ;: 4.96 4.83 4.61 4.27 3.77 3.03 0 c . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-22 c NACA RM A52Fl8 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-
17、npw mffh .4 c 1.22 ff. - Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-2 -I 0 . . 0 ./ .2 -3 .4 .5 .6 .7 .8 .9 LO- Fmtitm ofsem$xm, (b) DisMbutim dtwfst and thickmss mtio. I Provided by IHSNot for ResaleNo reproduction or networking permitted wit
18、hout license from IHS-,-,-I . . I L , k - El/r;otic - Wing with I)0 twist, At = 0 - whg with twfst, W= 0 - Wing with hvist, M = 0.83 ffgum 2.- Th fheo#tical spanwlse d&?Whm of c& &i&t by the M?siglsf mefld ti 0 fift &l%&rt of 0.4. Provided by IHSNot for ResaleNo reproduction or networking permitted
19、without license from IHS-,-,-Small t c c t t c . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-(8) Wing-fmelage model in the wind tunnel. (b) Details of the fences. Figure 4.- Photographs of the model. Provided by IHSNot for ResaleNo reproduction o
20、r networking permitted without license from IHS-,-,-R) W I I I t&t I / / I / t . . . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I ! ! : ! ! ! 4 8 12 .A6 .P .# 0 -04 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
