1、-_I-.- ,./*-. -_ .- : _ .- . . RMA55Dll _ RESEARCH MEMORANDUM INVESTIGATION OF THE EFFECTS OF AN AIRFOIL SECTION MODIFICATION ON THE AERODYNAMIC CHARACTERISTICS AT SUBSONIC AND SUPERSONIC SPEEDS OF A THIN SWEPT WING OF ASPECT RATIO 3 IN COMBINATION WITH A BODY By David Graham and William T. Evans Am
2、es Aeronautical Laboratory Moffett Field, Calif. NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS WASHINGTON June 28, 1955 Declassified February 26, 1958 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACARM A55Dl.l NATIONAL ADVISORY CaMMIEcEE FOR AERONA
3、CTICS REsEARc!E MEMoR.ANDuM INKESTIGATION OF TRR EFFECTS OF AN AIRFOIL SECTION MODIFICATION ON TRR AERODYNAMIC CRARACTWISIICS AT SUBSONIC AND SUPWSUNIC SPRRDSOFATRIN SWEPTwINGOFASPFCTRATIo 3 IN CCKI3INATIONWITEABODY By David Graham and W3.llism T. Evans A wind-tunnel investigation has been conducted
4、 to determine the effects of an airfoil section modification consisting of a greatly fncreased leading-edge radius and slight forward camber on the aerody- namic characteristics of a thin swept-wing-body combination at Mach numbers from 0.06 to 1.9. The basic wing had an aspect ratio of 3, taper rat
5、io of 0.4, leading-edge sweep of 45O, and an NACA 6kAOO6 air- foil section perpaculsr to the quarter-chord line. A large-scale model was tested at low speeds and at Reynolds numbers from 4.x;i95. Similar computation at M = 0.31, corresponding to R= 6, indicates critical pressure coefficfents were pr
6、obably 21f may be noted that in figure 3(b) the value of CD for the basic model is indicated as being more than the value for the mzdiffed model. This is due to the fact that tubing from preseure orifices in the basic model WAR run-down the tail strut, part of the tubing being exposed to the air str
7、eam and giving rise to s*e drag. Thie tubing was not present in the test of the modified model. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-10 NACA RM A55Dl-l . reached at outboard stations at a lift coefficient of about 0.65, some- what before t
8、he measured drag bresk. c l?igUres 14 and 15 shar that at high subsonic speede, the aerody- namic characteristics .of the basic and modified models were not signifi- cantly affected by varying the Reynolds number from 2.9 to 5.7x106. Attention ie directed, however, to figure 14(b), wherein two sets
9、of data for R = 5.7x106 are shown on the drag polars. The principal set of data (unflagged symbols) was obtained after a piece of the original Wing had been cut out of each Wing panel and replaced with wax. The flagged symbols represent data obtained prior to this alteration. AB can be seen, a discr
10、epancy exists between the tW0 Bets of data at lift coefficients above 0.2. (To avoid cluttering the figure, no flagged symbols are shOWn below CL = 0.2, since the two sets of data are in substantial agreement in this region.) No explanation for this discrep- ancy is evident at this time. In figure 1
11、4(c), the data for R = 5.7106 were also obtained with the altered wing. CONCLUDING REXr2= li.5 I * - Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-18 NACA RM A55Dll TABLE II.- COORDINA!l?ESOFTAIRFOIL SECTIONSUSED All coordinates are referred to the
12、 chord of the NACA 64AOO6 section, and are in terms of percent of that chord. Asterisks indicate ordi- nates that are identical to those of the NACA 6kAOO6 section. Ordinates of modified sections NACA Lower surface Station 64006 ordinate Upper surface Two-dimensional and large-scale Hiod models -1.5
13、0 -1.38 -1.38 -1.48 -1.25 -.60 -2.065 -2.065 -1.00 -.34 -2.315 -2.315 -075 -a45 -2.49 -2.49 -025 .16 -2.75 -2.75 0 0 -2.855 -2.855 025 ;5 -2.955 -2.955 050 l 485 -3.04 -3.04 975 l 585 * -3.10 -3.10 1.25 l 739 -3.22 -3.22 ,:Z 1.399 1.016 :;=g5 -3:67 :;-g; 7.5 1.684 -3170 10 1.919 -3.68 -3.74 15 2.283
14、 -3.61 -3.655 20 2-557 -3.45 -3.445 25 2.757 -3.235 -3.245 E 2.896 2.977 2.999 -3.095 -3.02 -3.105 -3.025 -3.000 -3.000 45 2.945 * t ; 2.825 2.653 2; 2.188 2.438 E 1.907 1.602 1.285 85 -967 ; .64g 9331 100 .013 V V V Leading edge Leading-edge radius = 1.19 radius = 0.246 Center of leading-edge circl
15、e: x = -0.31 k = -1.33 Maximum thickness of modified section in percent of true chord: 5.91 Maximum camber of modified section in percent of true chord: 0.90 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA RM A55Dll Dimensions given in feet unle
16、ss otherwise noted 0.0138 c i/ - $sL-Q- Section A-A (used for two-dimensional model) of 64A006 sections c Figure l.- Two-view draing of the lerge-scale model tested at low speeds in the Ames R = 9.7x10s. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-
17、,-. R 1.2 I I I I / -%+ +$ E=o.z / I / I l-l ID I I I I . CD (b) CL VS. CD Figure 3.- Concluded. , 1 . I Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I 1 I L 8 zcl 24 w 0 434 -.08 -.I2 a Cm (8) CL VS. 3 c, Figure 4.- Low-speed aero R = 9.7xlOe. Pr
18、ovided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. 0.064 f = ) E = 0.E 1.2 I 1 I I I - CD, t cLp TEA e = 0.8 1.0 - 1.4 0 .04 .08 .I2 .I6 20 .24 -28 32 .40 44 40 s2 CD (b) CL VS. CD Figure 4.- Concluded. . I I t I , Provided by IHSNot for ResaleNo reprod
19、uction or networking permitted without license from IHS-,-,-1.2 1.2 1.0 .a CL .6 -4 .2 0 $ F $2 R = 9.7x10s. G Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.8 Model with modification of Outbclcrd 60% Qfspan, with abrupt dixmtinuity Q Outbaxd 60% o
20、f span, with faked discontinuity 0 -A- -.2 0 04 Lx .I2 .16 20 24 28 32 33 .40 .A4 .A8 CD figure 5.- concmaea. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.4 -E8 I I -4 I 11-1 0 4 I I 8 I III II I I I I E 11 I t I 20 fwM=a6 a (a) CL va. a Pigure 6
21、.- High-speea aerodynmc cbaracterietics of the basic and modifiea mall-scale moael; R = 2.9xm3, -2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-.6 I I 9w I I A I PYI ” -2 -4 El Mcdfied model H #T # b) CL VB. c, Figure 6.- Continuea. I I I I I I I I I I I I N co Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I I -2 -4 -O .I6 20 24 28 .32 forM=o.ci CD (c) CL ,a. CD Figure 6.- Concludea. . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
