1、cc C cc U i- t Li 5 C 4 !- 4 RESEARCH MEMORANDUM LONGITUDINAL AND LATERAL STABILITY CliAMCTERISTICS OF A LOW-ASPECT-RATIO UNSWEPI“WING ARPTLANE MODEL AT MAC3 NUMBERS OF 1.82 AND 2.01 By M. Leroy Spearman and Cornelius Driver J Langley Aeronzutical Laboratory 5 Provided by IHSNot for ResaleNo reprodu
2、ction or networking permitted without license from IHS-,-,-t J A r RZSEKRCE MEEK)“EIUbI LONGITUDIIUL AND LA- SWILSTY CHAFWTERISTICS OF A LOW-ASPECT-RATIO UNShm-1m-G AIXPLANE MODEL AT MACH NLNBEBS OF 1.82 AMD 2.01 By 14. Leroy Spearman and Cornelius Driver An investigation has been made in the Langle
3、y 4- by bfoot supersonic pressure tunnel at Mach numbers of 1.82 and 2.01to detemine the longi- tudinal and leteral stability c9secteristics of a fighter-type airplane model having a low-asgect-retio u-n-s-xept Idng and a high horizontel tail. The coqlete mdel and various coxbir?ations of component
4、parts were tested, as well 8s vzrious configurztion changes including a nodified vertical tail, several ventral fins, end severs1 externel store arrzngements. 53.e results for the basic cleen corziguration indicated a region of reduced lo-n-gitudiml staSility at low lifts at a Bkch nurr?ber of 2.01
5、that was zpsarently caused by fuselage flow fields or vertical-tail effects on the horizontel tail. R considerable portion of the verticel-;ail contribution to direc- tional stability ms required to overcome the lerge unstable yaving roomeni of the body. Tke directional stability decreesed rapidly a
6、t high angles of sttsck, primxily beceuse of increased instability of the wing-bo. me geometric cherecteristics of the nodel and variom external store arrangenen5s are given in table I. Tke model was eqxfpped with E. wing havirrg 18.1 sweep of the quarter- chord lhe, an aspect ratio of 2.45, a taper
7、 rztio of 0.377, and 3.36 per- cent modified circular-arc sec-iions. Tle wing was set at zero incidence to the fuselage reference line end had loo negative geometric dinedral. The tesz model m.6 not equip2ed with internal ducting end the side inlets were faired into the contour of tie body. R modifi
8、ed vertical tail having a larger area and increased s-iceep (fig. 2(5) wes tested to determine its effectiveness in improving the directional characteristics at angles of attack. Several ventral-fin configurations were also investigated. The ventral fins were thin alumi- num phtes with beveled edges
9、 and were fitted to the bottom of tne hoe. (See fig. 2(c).) The mo5el was equipsed with a horizontal tail fixed at zero incidence only. The eernal store arrangements tested were es follows: (a) a pylon mounted fuselage store (fig. 3(a), (5) GWO fuel tanks, oce on each wing tip (fig. 3(b), two Sidewi
10、nder missiles, one on each wing tip (fig. 3(c), 2nd four Felcon missiles, two on each wing tip (fig. 3(2). . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I 8 Forces and monents were measured through the use of e six-component internal strain-gege
11、balence and indicating system. CORRZCTIORS hi ACCW-CY , The angles of attack and sideslip were corrected for the deflection of the balznce and sting under lozd. *The drag ettO.OOlO. The conditiolzs for the tests were as I“ol1ows: M = 1.82 M = 2.01 Remolds number based on mean gemetric chord . . . .
12、. . . . . . . . . . . . . . . 1.02 x 106 1.38 x 106 Stagne%ion deleoint, 4 . . . . . . . . . . . . -20 -20 Stagnation presswe, lb/sq in. abs . . . . . . 10 15 Stagmtion taperatwe, OF . . . . . . . . . . 100 110 Mach number variation . . . . . . . . . . . . . fO .01 fO .01 Flow angle in the horizo?za
13、l or ver2ical plane,deg . f0.1 f0.1 rr Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Tests were rase through an angle-of-attack ant5 sideslis range UI, to the basic l tine extern 2nd the summary data, in figures X) to 24. Lmgitudiml Characteristics
14、 for Clem- Configuration The aerodynzmlc chzracteristics i3 pitch for variocs combinations of ncdel cqonents are presen-led in f ipe 5 ?or M = 1.82 and in figure 6 for M = 2.31. Tne ediiltion of the horizontal tail to the body-dng- vertical-tail configuation provides raSner large increases in lift w
15、ith increasing angle of attack and, of course, increases the pitching-nanent slope Cna for bozki Nezh nuibers. The addi%ion of the vertical tail (fig. 5) had litcle effect other than to cEuse En increase in drag an frcz fuselage ?lo%- fieide or vertical-tail effects on the horizon- tal tai:. CXL cqL
16、 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA i31 561106 7 k Some interference effect of the -ents grovided by the tail are decreased in the presence of the Xing at the lower angles ol“ zttack. Above about a = 16O the reverse 5s true, the tai
17、l lift and moment increnents being sonewha% greater in ,the presence of the wing. Laterel and Di-rectiond Characteristics for Clean Collfigwa-Lion Effects of component parts.- The aero6ynami.c characteristics in SideSliD at M = 1.82 were obtained Tor several combinfluer_ce of -;he horizontal tail is
18、 also seec at ;G = 80 when the wicg is renoveC (Tig. 12(3). At c: = 18.2 (fig. 12(d), hovever, the ir?lilence of ;ne hGriZOlia1 tail indi:eAed by the negE-Live vEriaticn of a Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-C .1 1 NACA BY 36106 9 Cm -
19、ained experimentelly zt a = 2.4O. Some increase 5th increasing angle of attack is indicated in the increaent of Cyp, Cnp, and Czp provided by the enlarged tail (fig. 22). This increase apparently is a result of favorable side-ash in the region above Lhe center of the wing-body wake. The addition ol“
20、 the enlarged swest vertical tail is sufficient to increese the angle of attack at which = 0 frm about loo to about 17.5 (fig. 22). The interference effects of the horizontal tail, of comse, are cot included in these results so that the incren?ental con- tri3utions to tne lateral stability provided
21、by the enlarged tail my be altered when the presence of a horizontd tail is considered. CnP Effects of ventral fins.- Tine effects of verious ventral fins on the sideslip characteristics et M = 2.01 of the complete model with the. basic vertical tail (V2) were detedned. These effects are shown throu
22、gh the angle-of-attack range at p = 5.3O in figfire 15 and the resdts are smrized in figure 23. The effects of two of the ventral fins =re shown throw- the angle of sideslip range at CG = 8O in figure 16. I Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS
23、-,-,-Each of the ventral fins, when added to the basic model, provided some increase in the lateral force afid yawing moments and a slight reduc- 1. tion in the rolling aments (fig. 23). With the exception of Ul, the ventral fins provided slightly Lrger increments of Cyp per unit area than Si3 the v
24、ertical tails. However, all of the ventral fins provided signif icaztly smaller increments in per unit area than did the vertical tails, probably because of the shorter moment arms available with the ventral fins. The increments provided in CYp and Cnp by ck-e ventral fins (fig. 23) were essentially
25、 constant with sngle of attack and resulted in only a small increase ill the angle of attack for vhich CnP CnP = 0. It is interesting to note that the increments in CY and Cnp pro- vided by ventral fins Ul and U2 are essentially the same although U2 has less area an2 a shorter Ill0n;en-t arm than Vl
26、 (fig. 23). This again may be an im5ic-body juncture, which 3elow the center of the wing-body wake Eppears to be averse. As a result, tke added area of ventral fin Ul may be offset by en adverse sidewash. This result is p.sr+,icCLarly interesting inasmxch as the smaller ventral fin (U2) would be mor
27、e desirable in Mach nmbers of 1.82 a?d 2.01to determine the longitudinal and lateral stability chrazteris5ics of various arrange- xents 0; a fighter-%yge zirglane rr.odel havi?G a low-aspect-ratio, tapered, unswept wizg EX-he configLnation having no horizoEte1 tail increased the direczionai stsbilit
28、y at low angles of atcack by an aaount antieiqated frm estirnE;tes and ms sufficient to increase the angle of attack at *ich the Cirectional stability became zero from zbcut 10 for the basic tail to about l7.5O. 5. Ezch of various ventral fins, when aided to the basic model, pro- vided an frcrease i
29、n the directionzl stability thzt ms essentially con- scan5 with angle of attack bEt resulted in only a smll increase in the angle cf at-,ack for which the directional stability became zero. 6. The addition of varioxs tip-mounted stores had little effec7; on the loztuciinal characterlstics other than
30、 to increase the ninimm drag level but did resnlt in a decrease in directional stebility at the higher Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA RM 5606 - 13 angles of a-itsck. The addition of a body-mounted store resulted in a decrease in
31、 directional stajilizy throughout the angle-of-attack range. Langley Aeronautical hborat.ory, National Advisory Committee for Aeronactics, Lengley Field, VEL., July 20, 1956. 1. Smith, Willard G. : Wind-Twml investigation at Subsonic and Suger- sonic Speeds of a Fighter Model Employing a Low-Aspect-
32、Ratio Unswept Wing anu E Horizoctzl Teil Mourned We11 Above the Wing Plane - Longi- tziiinal Stability and Control. NACA RFul A54D05, 1954. 2. Robinson, Ross 9.: Longitudinal Characteristics of an Unswept-Wir-g Fighter-Type MoOel With ExLernal Stores at E Mach Nunber of 1.82 anii Sone Effects of Hor
33、izortal-T.si1 and Yav-DanSer Deflection on the Sideslip Derivatives. NACA Rbf 5526 , 19g6. 3. Speermm, M. Leroy, ami Henderson, Arthur, Jr.: Some Effects of Air- craft Copx-igurat io= on Static LongitudiGel aod Directiocal StKbilFty Cnuecteristics at Supersonic Each Nuiers Belov 3. WACA RM L55Li5aJ
34、1956. 4. Harmon, Sidney M., acd Jeffreys, Is8,beU.a: Theoretical Lift and Demping in Roll of T%in Wings With Arbitrary Sweeg arld Taper at Supersonic Speeds - Sspersonic Leading and Trailing Esges. PJACP; .TN 2111: , 1950. c Provided by IHSNot for ResaleNo reproduction or networking permitted withou
35、t license from IHS-,-,-14 NACA F34 L56HO5 8 TABU 1.- GECMETRIC CHARACTERISTICS OF MODEL . Wir.g: Area. sqft 0.3137 Sgan. in 10.480 Kean geometric chord. in 4.584 Assect ratio 2.45 Taper ratio 0.377 Sweep of leading edge. deg . 27.1 Sweep of quarter-chord line. deg 18.1 Sweep of 70.4-percent-chord li
36、ne. deg 0 1ncidence.deg . 0 Dihedral. deg . -10 Airfoil section . Modifiei 3.36-percent circular arc Horizontal tail: Area. sq ft Span. in Aspec-; rztio Mezn gemetric chord. in Taper ratio Sweep of leading edge. deg . Sweep of quarter-chord line. deg Sweep of rnidchorC line. deg . . Incidelce (on te
37、st nodel). deg . Airfoil section. root . Dihedral. deg . Airfoil section. tip . . . . . . . . . . . . . . . . . . . . . . 4.93-percent 2.61-gercent . . 0.0771 5.72 . . 2.116 2-95 . . 0.311 19.5 10.1 0 0 0 circular arc circular arc Vertical tails: v2 v3 Area to theoretical root. sq in . 8.30 11.7 Ssa
38、n from theorekical root. in 2.66 3.61 Mean gemetric c:?ord. in . 3.44 3.48 Asgect ratio (par, el) . 0.85 1.11 Taper ratio . 0.378 0.371 Sveep of leading edge. deg 52.3 44. 0 Sweep of quarter-chord line. deg . 34.9 47.4 AirToil sectior? Modified 4.25-percent circular arc Tip chord. in . . 1.70 1.76 T
39、heoretical root chord (1.52 in . above fuselage reference line). iz . . 4.50 4.74 Venkral fins: Area of U1. sc_ in . 5-8 Aree. of U2, sq in . 395 Area of U3. aq in . 2.2 Area of U4. so_ in . 1.6 Section Modifled flat plate. 0.050 in . thickness Provided by IHSNot for ResaleNo reproduction or network
40、ing permitted without license from IHS-,-,-. TABLE I.- GEOMETRIC CLIARACTEBISTICS OF MODEL . Concluded Fuselage : Lengtlrl. in . 24.60 Maxhua frontal area. sa_ f-i 0.0368 Base area. sq ft 0.0136 Lengtn-diazneter ratio . 9.25 Body store (AI): Length. in . 6.20 Dianeter (llaxmun). in . 0.88 Lengtn-die
41、meter ratio . 7.05 Frontal erea. sq ft 0.00463 Wetted area. sq ft 0.1211: Tip ta-dcs: Length. in . 8.46 Length-diameter ratio . 10.58 Frontal ares. sq ft 0.0035 Diameter (maxinun). in . 0.80 Sidewinder missile: Lengtn. in . 4-40 Length-dianeter ratio . 22 Dlmeter (mximm). in . 0.20 Fronkal area. sq
42、-pt 0.0004 Falcon missile: Lengtn. in . 3.46 Diameter (maxirmn). in . 0.256 Length-diameter ratio . 13.52 Frontel area. sq I“t 0.0006 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I“ ch Figure 5 6 7 0 9 10 11 12 A - M 1.82 1.82 1.02 2.01 2.0.1 2.01
43、 2.01 1.82 2.01 1.82 1.87 1.87 1.8% 1 . to 14 . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- “ - - I I TADU 11.- INDM OF FIGURES - Concluded 20 Effectn of extern1 stores on sideslip derivativee. M = 2.01. 2h Effecka of ventral fins on sideslip de
44、rivutiven. M = 2.01. 23 Effects of vertical-tail plan farm on aidenlip derivatives. M = 2.01. 22 Effectn of cauponent prtn on sidesUp derlvutlveo. M = 2.01. 21 Effecto of cmponent parts on oldeslip derivatives. M P 1.82. Provided by IHSNot for ResaleNo reproduction or networking permitted without li
45、cense from IHS-,-,-NACA RV 5606 I I Relative Wind .- ,el, X Relative Wind (a) Systex of stability axes. Figwe 1. - Systems of axes end notation. . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA ?Jd 561106 Rela ti ve Wind I B s - Sit MZ 4 I X X
46、i A,V I L ,a / Relative Wind I2 (b) System of body axes. Figure 1. - Conclirded. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-(a) Basic model. Figure 2.- Details of test model. All dimensions in inches unless other- wise noted. I 4 . c Provided by
47、 IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-1 1 “ “ I - v, -y-/- t-*76“ - (b) Vertical-tail details. Figure 2.- Continued. 5.13 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-1 “ - moment reference “_“_ - “
48、.“.“ - “-.- - _“ - - - - - - -.“ “ Sharp “43 L“ 1.65-4 “ 9.30 - “ _j (e) Ventral-f in details. Figure 2.- Concluded. II , c “ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I I / “ “- “-“ - “4 1- c- moment reference - “- _ f “ ,L - “ -“ 1.68 i r2447-7 “- Ld 9.70 6.20 - -I (a) Fusel
