NASA NACA-TN-3529-1955 The transonic characteristics of 36 symmetrical wings of varying taper aspect ratio and thickness as determined by the transonic-bump technique《根据跨音速撞击技术决定的变.pdf
《NASA NACA-TN-3529-1955 The transonic characteristics of 36 symmetrical wings of varying taper aspect ratio and thickness as determined by the transonic-bump technique《根据跨音速撞击技术决定的变.pdf》由会员分享,可在线阅读,更多相关《NASA NACA-TN-3529-1955 The transonic characteristics of 36 symmetrical wings of varying taper aspect ratio and thickness as determined by the transonic-bump technique《根据跨音速撞击技术决定的变.pdf(132页珍藏版)》请在麦多课文档分享上搜索。
1、Provided by IHSNot for Resale-,-,-TECH LIBRARYKAFB,NM,CNATIONALAndynamicADVISORY C FOR AERONAUTICS lllillllllllllllMllMMllclhb495!l!ECIINICALNOTE3529THE TRANSONICOF VARYINGCHARAC=STICS OF 36 smmmucfu wmwsTAPER, ASPECT RATIO, AND THICKNESS ASD BY THE TRANSONIC-BUMPTECHNIQUE=By Warren H. Nelson, Edwin
2、 C. Allen, andWalter J. I33, and 0.6), and 2 (taper ratios of 0.33, 0.5, and 0.72), andNACA63AOOX sectionswith thickness-to-chordratios of 8, 6, 4,and 2 percent.The results indicate that the greatest effect of taper on the lift-curve slope occurred for the wing having the highest aspect ratio andthe
3、 thinnest section. This effect, which was to increase the lift-curve slope with increasing taper ratio, diminished as the.aspectratiowas decreased and/or the thickness increased. Increasing taper ratiogenerally increasedthe over-all center-of-pressuretravel for all thewings in going from subsonic to
4、 supersonic speeds.INTRODUCTIONA comprehensiveinvestigationhas been initiated in the Ames 16-foothigh-speed wind tunnel to determine the transonic aerodynamic charac-teristics of wings having various aspect ratios, thichessesj cambers,and plan-form taper ratios. The experimentaldata on the,effects o
5、faspect ratio, thicbess, and camber have been reported in references 1and 2, smd analyses of the data using the transonic similarityruleshave been reported in reference 3. -%upersedes recently declassifiedNACA RMA3129by Warren H. Nelson,Edwin C. Allen, and Walter J. Kkumm, 1953. . .-. .-. . _._. _ _
6、 . . _ .Provided by IHSNot for Resale-,-,-2 NACA TN 3329.The purpose of this report is to present that part of the general. ,investigationinvolving the effect of plan-form taper.Three basic plan-form taper ratios, 0, 0.2, and 0.9, were investi-gated for wings having an aspect ratio of k and NACA 63A
7、-series sym-metrical sectionswith thickness-to-chordratios of 2, 4, 6, and 8 per-cent. These wings, in turn, were reduced in span by cutting off thetips to give aspect ratios of 3 and 2. The resulting plan-form taperratios for the wings having an aspect ratio of 2 were 0.33, O.z,and 0.72.NOTATION% d
8、rag coefficient,twice semispan dragc minimum drag coefficient* friction-dragcoefficient assumed equal to the minimum dragcoefficientat 0.6 Mach number;“-(L ,% minimum pressure-drag coefficient,assumed equal to ,( )Ckin %CL lift coefficient,twice semispan liftqs% pitching-momentcoefficient,referred t
9、o 0.21j 6,twice semispan pitching momentqszAMMLsvb2aspect ratio, mean Mach numberlocal Mach numbertotal wing area, Mce wing area of semispanmodel, sq ftvelocity, ft/sectwice span of semispanmodel, ftlocal wing chord, ft* b/2czdymean aerodynamic chord,fob/2C dyl,. Provided by IHSNot for Resale-,-,-NA
10、CA TN 3529 3!J. dynamic pressure, p, lb/sq ft2tF thickuess-to-chordratioY spanwise distance from plane of symmetry,fta angle of attack, degtip chordtaper ratio, root chordP air density, slugs/cu ftdCLx slope of lift curve measured at zero lift, per degdCm slope of pitching-moment curve measuredAPPAR
11、ATUS AND MODELSThe tests were conducted in the Ames 16-footat zero lifthigh-speed wind tun-nel, utilizing a transonicbump. A description of the bump may be._.found in reference 4. The aerodynamic forces and moments were measuredby means of a strain-gagebalance mounted inside the bump.A photograph of
12、 one of the wings of aspect ratio 4 mounted on thebump is shown in figure 1. The principal plan-form dimensions of thewings are shown in figure 2. The profiles used were NACA 63AOOX sectionswith thickness-to-chordratios of 2, 4, 6, and 8 percent (ref. 5). Threebasic wings of aspect ratio 4 having ta
13、per ratios of O, 0.2, and 0.5 andequal areas were constructedof steel for each thickness-to-chordratio.Aspect ratios of 3 and 2 were obtained by successivelycutting off thetips of the wings. The following aspect-ratioand taper-ratio combi-nations were included in the tests:Aspectratio Taper ratio4 0
14、 0.20 0.503 .14 a71 33 .602 a7133 .50 .72The mean aerodynamic chord of the wings changed with the taperratio; this change was such that.at any one aspect ratio the mean aero-dynamic chord of the wing with the highest taper ratio was about. . . - . - - . . Provided by IHSNot for ResaleNo reproduction
15、 or networking permitted without license from IHS4 NACA TN 352980 percent that of the wing with the lowest taper ratio. The wing tipswere faired by us one-half of the wing thickness at each chord station ,as a radius. JA fence 3/16 inch from the bump surfacewas used to prevent theflow through the ga
16、p between the wing and bump surface from affectingthe flow over the wing.overThe lift, drag, anda Mach number rangenumber range depended onTESTS AND PROCEDUREpitching-moment characteristicswere obtainedof 0.6 to 1.10. The correspondingReynoldsthe wing mean aerod “c chord. tbe extreme/range of Reynol
17、ds numbers being rom about 1:4 million to 2.0 million.The angle-of-attackrange, in general, was from -2 to the stall, or towhere the root bending stress became critical.Aldecreasingthe aspect ratio and/or increasingthe thiclmess ratiodecreased the magnitude and the variation with Mach number of the
18、lift-curve slope. These effects on rectangul= wings have been correlatedinreference 3 by use of the transonic similarityrules. The effects of- -Provided by IHSNot for Resale-,-,-NACA TN 3529 5taper on lift-curve slope were not nearly so pronounced as were thoseof aspect ratio and thickness. The larg
19、est effects of taper occurredfor the wings of aspect ratio 4 where the taper ratio varied from Oto 0.5. (It should be pointed out that, in these tests, as the aspectratio was reduced, the values of taper ratio increased and the range oftaper ratio decreased.) Moreover, the effects of taper were grea
20、testfor the thinnestwings and decreased as the thicknesswas increased.For the wings of aapect ratio 4, increasingthe taper ratio increasedthe lift-curve slope, this effect being greatest for taper ratiosbetween O and 0.2. The 8-percent-thickwings, having taper ratiosof 0.2 and 0.5 (aspect ratio 4),
21、had the type of variation of lift-curveslope with Mach number associatedwith shock stall. In the case of thewings of aspect ratios 2 and 3, there was little effect of changes intaper ratio on the lift-curve slope, except for thewing of aspectratio 3 having a thicbess ratio of 2 percent. For this win
22、g, therewas an increase in lift-curve slope with increasingtaper ratio through-out the Mach number range.( )The variation of minimum pressure drag coefficient CCDfwith Mach number for the wings is shown in figure 14. The effect ofchanges in thiclmess is ite apparent; decreasing the thickness ratioca
23、used a reduction in pressure drag, as would be expected. However, theeffects of taper and aspect ratio are not so apparent. In”general, therewere no large, significant,or consistent effects of taper ratio oraspect ratio on the minimum pressure drag, although some drag reductionwas obtained at the hi
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