1、 . . “ “ RESEARCH MEMORANDUM AN INVESTIGATION AT MACH NWERS OF 1.41 AND 2.01 OF THE AERODYNAMIC CHARACTE-l3JXtICS OF A SWEPT-WING SUPERSONIC BOMBER CCINFIGURATION By Norman F. Smith and Lowell E. Hasel Langley Aeronautical Laboratory Langley Field, Va. CLASSIFICATION CHANGED u- . WASHINGTON 4 Februa
2、ry 1,1956 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-D AX INVESTIGATION AT WCH NUMBERS OF 1.41 AND 2.01 OF !ITYE AERODYNAMIC CHWCTERISTICS OF A ST4WT-WING SWEFlSONIC BOM8ZR CONFIGUIWTION By Norman F. Smith w-d Lowell E. Hasel An investigation of
3、 the aerodynamic characteristics of a swept-wing supersonic bopher configuration has been conducted in the Langley 4- by 4-foot supersonic pressure tunnel. The tests were perforned at Mach wing nean aerodynamic chord. - b Ilurnbers of 1.41 and 2.01 at a Reynolds nunber of 2.6 x 10 based on the 6 T T
4、he model incorporated a tapered wing heving an aspect ratio of 3.5, a taper ratio of 0.2, a thichess ratio of 5.5 percent (streamwise an6 47O sweep or“ the quarter-chord line. The longitudinal and lateral force characteristics of the model and various conibinations of its components, including sever
5、al jet nacelle installations, were investigated. The efzects of a modified wing, two horizontal tail positions, and a shortened fuselage were also studied. The results obtained from these investigations are presented in this report. The aerodynamic investigation of this model disclosed no unusual st
6、ability cb2racteristics or %ch nurllber effects. The choice of nacelle installations appears to be a major decision, one greatly efl“ecting the perforname of the airplane. At a hch nmber of 1.41 md lift coeffi- cient of 0.1, the buried nacelles increased the drag of the basic model by 9 percent, whi
7、le the best pod nacelles increased the drag of the basic model by 27 percent. INTRODUCTION * -An investigation of a svept-wing supersonic boniber configuration bas been made in the T-lengley 8-foot transonic tmnel (ref. 1 ) and the Y Provided by IHSNot for ResaleNo reproduction or networking permitt
8、ed without license from IHS-,-,-s Langley ;+- by 4-foot su;?ersonic pressure tunnel. This report presents the results of the iovestigation in the latter tunnel at the ogive-nose configurations had the lowest mini- mum drags of 0.027. Lateral Force and Moment Characteristics Model breakdown.- The lat
9、eral stability characteristics of various con-blnations of fuselage, wing, and tail are shown in figure 25. The configurations which do not include the vertical tail are direc- tionally unstable. The vertical tail produces a high degree of direc- tional stability. Addition of the wing to the fuselag
10、e has a small effect, changing the slope of the curve in a stable direction. When added to the fuselage with tails, however, the wing introduces unfavora- ble sidewash and changes the slope of the curve slightly in the direc- tion of decreased stability. The following table compares the measured val
11、ues of Cn, due to adding the vertical tail to the fuselage and to the fuselage plus wing with the 7mlues of Cnq calculated for the vertical tail by mans of linear theory (refs. 3 end 4 1: Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-s Enq due to v
12、ertical tail M = 1.41 M = 2.01 3 Conriguration Wing on . -. 0026 - -0037 Linear theory - -0031 - -0043 Wing off -0.0027 -0.0041 The calculation assumed a lifting surface whose semispen plan form was identical with that of the vertical tail. This assunption effectively introduces a reflection plane a
13、t the root of the vertical tail, a condi- tion not exactly fulfilled by the fuselage. The table shows that the magnitude of this incremental stability derivative can be approximately calculated by the linear theory in this case. The mgnitude is slightly underestimated, as is the change with Mach nun
14、fber. The rolling-moment chracteristics (fig. 25) show tht the configu- rations without the vertical tail have approximately zero efzective figuration is produced largely by the vertical tail. The position of the horizontal tail is shown to have (at M = 1.41) an important effect upon the rolling mom
15、ent produced by the vertical tail. The slope of the rolling-noment curve for the basic model is decreased by about one-half when the horizontal tail is Koved from the high to the low position. Examination of the yewing-morent and side-force curves shows that only a small increase in vertical-tail lo
16、ad occurred; hence, the change in rolling morcent is due principally to e vertical shift in lateral center of pressure of the tail group. Insufficient configurations were tested to explain the nature of this interference effect. - dihedral. The positive effective dfhe heme, the interference which ca
17、uses the difference in rolling monent between the pod llacelles at 0.50 m“d 0.60 semispen is not defined by the data obtained. - of all pod Eacelles is to decrease the effective dihedral of the basic The yawiog-noient variation is little affected by the nacelle installation. The slope of the lateral
18、-force-coefficient curve (fig. 29) is higher for the model with pod nacelles installed as a consequence of the lateral area presented by the rmcelle-strut combinetion. Conparison of original and shortened fuselage.- Two tests were made h at M = 1.41 with the fuselage shortened 4 inches from its orig
19、inal length oI“ 41.32 inches. Figure 30 shows a comparison of the lateral characteristics of the model witn the shorteced and long (original) fuselage. Th% changes in lateral force are small because the chal?ge in lateral hence, tne choice of engine-rAcelle installation is of 2jor Lmportance. At a M
20、ach n-der of 1.41 and lift coefficient of 0.1, the buried nacelles hcreased the dreg of the basfc model by 3 percent, while the best pod nacelles increased the drag of the basic model by 27 percent. The effectiveness of the horizontal tail in changing trin lift coef- ficient was about the same Zor t
21、he high and low positions, and the rela- tfve effectiveness of the elevator was proportional to the ratio of ele- vator area to stabilizer area. The wing rradification was found to have negligible effects on liTt and stability and increased the drag (at trim) of the basic node1 by 10 percent or less
22、 at both Mach nmibers. c The positive ef3ective dihedral of the basic model was due entirely to the ixrerent produced by the vertical tail. This increment was found ? to be app?oxirrately equal to that produced by chenging the wing dihedral from Oo to 5“. The rudder was of relatively low effectivene
23、ss in pro- ducing yaw. The shortened fuselage affected the lateral stehility in proportion to the change in moment am of the vertical tail. The longitudinal sta- bility, however, was less affected, apparently because of an accompanying increase in horizontal-tail effectiveness as e. result of decree
24、sed down- wash 5.2 the field closer to the wing. Langley Aeronautical Laboratory, National Advisory Committee for Aeroxutics, Langley Field, Va., October 22, 1952. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3D INTER-W DR4G PLZUD MASS-FLOV CHARAC
25、TERISTICS OF NACELUS Several assumptions must be made before the two static orifices which were installed in the necelle ducts can be used to compute the internal drag and mass-flow coefficients of the nacelles. The stagna- tion pressure sad temperature nust be assuqed to be ap between horizontal an
26、d ;np betwern horizontal and vertical tail Pi llrd vertical tall fllled Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Yuselege nose o hnpe Canopy u 19 25 26 97 28 99 30 33. 32 33 38 43 - ard TABLE VI.- TABULATION OF CONEIGUMTCONS FOR YAW 1STS Canop
27、y V Original I 1 Off Original 1 Off Original I Off OrlginE Off Off “- Cone-pod 60 Off I “- “ - c 50 Off - On 0 Off I- I “- I “- -“ “_ “- - On 0 Jr .L Buried “- c . - Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA RM L52Jl-7 a CL 0.028 -163 .292
28、 -417 .645 .535 .743 -027 cru 0.101 -062 .021 - .017 - -050 -.on -.w7 -102 CL -0.058 -.339 - .mb -218 .C81 - 472 -348 - -059 -5Q2 .502 % 0.025 -055 -035 .w6 -035 -053 -Curs “5 .a7 -087 0.036 -069 -034 -049 -0% .llo - 079 -149 -196 -037 0.030 -061 -029 -040 -052 -035 .on -110 -151 .198 -029 a -1.8 2.
29、6 -4 6-7 4.6 8.8 10 -9 -1.8 0.005 -0gg .a55 “082 “039 “127 - -165 - -174 - .174 -005 -4.1 -8.4 -6.3 -1.9 .2 2.4 4.5 -4.1 5.0 5 -0 -4.0 -6.1 -1.8 2-5 .4 4.5 8.8 6 -7 10.9 -4.0 -4.0 “_ - -8-3 -6.2 -1.9 -3 2-5 4.5 6.6 10 .g 8.8 -4.0 -8.5 -6.3 -4.1 -1.9 2-5 .3 4.5 6-7 10 -9 8.8 4.5 -3 - .8 -2 -9 -0.361
30、- .231 - .O% -05.4 I182 - 318 . Ul -559 -667 - 767 .4kO -184 - -015 -117 0.062 -030 .042 -029 -035 -077 - 053 -109 .150 -076 - 198 -035 -030 -028 0.164 .x5 - 079 .038 - .002 - -047 -.085 - .142 “117 -.le -.084 “a03 -019 -058 -0.106 - -248 -034 -167 .lag -295 -648 - 538 -748 - -107 0.131 - 179 -050 -
31、091 -007 “066 “095 “121 - -032 .132 0.070 -163 -121 -026 - .015 - “8 “060 - - 131 - -160 - -186 -072 56 -0 .om -.3Q - .228 -062 -324 -191 -448 -566 -776 -675 - .085 -4.1 -8.4 -6.3 -1.9 2.4 .2 4.5 5.6 -3.0 -4.1 -0.061 - .3kl - -209 - 077 -208 -341 -467 -524 - -069 -010 0.025 .036 -026 -034 -052 -078
32、-025 -094 -025 - 055 0.013 -103 -061 - -027 - -066 - -148 - . iio - .a08 “166 .013 . 57 -5 -9 -3.9 -1.9 2.0 0 6.0 4.0 8.0 10.0 -5.9 -0 .C%3 - .ob7 - -017 “033 - .oo2 .On -042 .027 - -062 -058 -019 -015 -012 -011 -010 -011 .ol2 .015 -019 .018 0.019 -016 .013 -012 . 011 roll .ox? -013 -016 -019 0.045
33、-084 -059 -040 -047 .a9 .064 . i23 .164 -213 -044 - 0.110 .088 .064 -040 “004 -017 -.6 -.048 -.m . llo 0.109 .w -070 -050 .016 .031 “001 - -015 -.M5 -109 0.032 .Ob3 -038 -054 .Ill -078 - 150 - 198 .031 .031 0.101 -148 -061 -019 - .026 - -066 -.w -.lk3 - .x25 -060 -4.0 -1 -8 -6.2 -3 2-5 4.5 6.7 10 .g
34、 8.8 -1.8 -6.1 -4.0 -1.8 .h 2-5 6.7 4.5 8.8 10.9 -4.0 -0.093 “239 .I77 .Ob3 -436 -311 -662 - 554 -762 .043 -0.243 - -100 .039 -171 -431 - 307 .550 - 657 -7% -.ow -0.312 “188 -.04g -209 -082 - 332 .w :z .757 “050 -0 -063 - -048 - -036 - -022 “010 -002 -014 -027 -038 - -062 -0.122 - .263 -.397 -035 -
35、lsg -329 .4Q .589 - 708 -814 - -115 -5.9 -3.9 -1.9 .1 2.0 6.0 4.0 8.0 10.0 -5 -9 -4.1 -8.4 -6.2 -1 .g 2-5 -3 4.5 6.7 11.0 8.8 -4.1 O.Ok7 -035 -034 .040 - 057 .081 -113 .153 -200 -035 0.051 -034 .wk - 033 .5 -051 - 075 -148 -109 - 196 .02k 0.165 -120 - 079 - 037 - .oc9 -.OM - -082 - -109 -.I27 .=9 0.021 .002 - .021 “040 “0% “080 -.om - .11k - -12:. - -133 - -021 “ 0 -085 -1- -182 .Ob “008 - .088 - .052 - -140 - .116 - - 157 .08k -8.5 -6.3 -4.1 -1.9 2.4 -3 4.5 6.7 8.8 -4.1 10 -9 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
