1、! i L., ? TEHNICXL NOTES HATIONAL ADVISORY COMMITTEE FOR AERONAUTICS No. 703 BIND-TUXNEL SNVESFIGATION OF EFFECT OF YAW ON LATERAL-STABILITY CBARACTERTSTICS - - I - FOUR N.A.C.A. 23012 TINGS OF VARIOUS PLAN IfORMS t PiITH AND BITIiOUT DIBEDRAL _. , i By M. J. Bamber and R. 0. Kouee Langley Bdemorisl
2、 Aeronautical Laboratory . 1 .s Washington April 1939 - -*- - _-_, .- ._ _ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. . NATIONAL ADVISORY COMMITTEE TOR AERONAUTICS TECHFIOAL XOTE X0. 703 XIXD-TUNNEL INVESTIGATION OE EFEECT OF YAV ON LATERAL-ST
3、ABILITY CZIARACTERISTICS I - FOUR N.A.C.A. 23012 flINGS OF VARIOUS PLAN FORMS $ITH AND TITEOUT DIHEDRAL By M. J. Bamber and R. 0. Xouse SUMARY Four N.A.C.A. 23012 wings were tested at several an- gles of yaw in the N.A.G.A. 7- by lo-foot gind tunnel. All the wings have rounded tips and, in plan form
4、, one is rectangular and the others are tapered 3:l with varions amounts of sweep. Each wing was tested with two amounts of dihedral and with partial-span split flaps. - The coeffi.cients of lift, drag, and pitching moment - are given for all the models at zero yaw. The coeffi- . cients of rolling m
5、oment, yawing moment, and side force are given for the rectangular wing at all values of yaw tested. The rate of change in the coefficients with an- gle of yaw is given in convenien t form for stability cal- culations. . IM!RODUCTION hathematical equations have been available for some time and conve
6、nient charts are given in reference 1 for predicting the lateral stability of airplanes, The prae- tical use of the equations or charts, however, depends upon the knowledge of the lateral-stability derivatives for the particular airplane in questdon. Among the fac- tors affecting the values of these
7、 derivatives are wing and fuselage forms and interference between the various parts of the airplane. .- - - The effect of various tip shapes and amounts of di- hedral for a rectangular Clark Y wing are given in refer- Provided by IHSNot for ResaleNo reproduction or networking permitted without licen
8、se from IHS-,-,-2 N.A.C.A. Technical Note No;, 7.03 ence 2. A theoretical QredfctJon of some of the latoral- stability characteristics for wings is given in reference 3. The prssent investigation of N.A.C.A. 23012 wings wae made to determine the effect of taper, swae,o, dihedral, and partial-span sp
9、lit flaps on the lateral-stability char- acteristics that depend upon sideslip, Lateral-stability qharacteristics of the.wings and equations for computing approximations to these character- istics are given in the report, The force and the moment coefficients are also included. ABPARATUS AND MODELS
10、The tests were made in the N.A.C.A. 7- by lo-foot wind tunnel with the regular 6-component, balance. The closed-throat tunnel is described-in refereac-e 4,and the balance is described in reference 5. The models are made of laminated mahogany to the N.A.C.A. 23012 profile. Plan-form and elevation dra
11、wings. of the wings are given in figure 1 and a photograph of one of the tapered wings mounted on the balance is given in figure 2. The tip plan fprm of.the rectangular wing is composed of two quadrants of simila,r ellipses; for t.he ta.perod wings, the ordinates of. the ,ellipses have been expanded
12、 in propar-tion to the t.aper of the indi.vidua.1 leading or trailing edges. The N.A.C.A. 23012 profile is maintained to the ends of the wings and, in elevation, the maximum ugper-surface section ordinates are in one plane. The area of the rectangular wing is 3.917 square feet and the aspect ratio i
13、s 6.383; for the tapered wings, the area is 4.101 square feet and the ,aspect ratLo is: 6.097. . . . The split flapsare made. of l/16-inch steel plates . attached .to the wing at an angle of- 600. The 20-perceat- chord split flapsare tapered with the wing chord and ex- tond.over 60 percent of the sp
14、an at the center section, which .is believed to be representative of modern practice. TESTS Each wing was tested with O“ and 5o dihedral and kith Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-N.,A.C.A. Technical Wote IJo.“ 3 c .u- .% i the partial-
15、span split flaps deflected 0 and. 60. Bach , wing combination w 16.61 percent of the root chord for the tapered wing with A = -4.750; 30.59 percent for h = 4.750; and 44.50 porcent for A = i4.00. The lift, the drag, and the pitching moments at 0 yaw were corrected for tunnel effects to aspect ratio
16、6 in free air, These data are given in figures 3 to 6 to show the aerodynamic characteristics of the models, The cross-wind force, the rolling moment, and the Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-c N;A.C.A. Te.chnical Note No,: 703, 5 t l
17、. . . yawing moment w.e_re corrected.for.initial asymmetry by de- ducting the values obtained without yaw from the values obtained with yaw. The coefficients were plotted against angle of yaw; ffgures 7 to 9 are sample plots. The stabilfty characteristfcs, ( ;-)o 8 (Sjo and ($j, were obtained by mea
18、suring at zero yaw 0 the slope of the curves of the coefficients against angle- i _ of yaw. Figures 10 to 12 give the variation of the sta- bility characteristics with angle of attack. For the an- gles of attack at and above the stall, the values become indetermInate, as is indicated by some of the
19、curves in figures 7 to 10. The variations in ( ac 1 -aJIl0 with u are given in figure 10(a) to (d) so that a direct comparison may be made with the data of previous investigations. . The angles of attack, yaw, and dihedral are believed to be within *O.l“ of the values given. Lxperiment,al eG- rors i
20、n the coefficients are believed to be within the following limits: CL, *0.005 (for maximum lift) CD *to.0005 (for minimum drag) .- Cy . 0.001 q 9 0.001 c rns *0.002, 0, I *0.001 DISCUSSION 1 It was found that the values .of ( dCt, - ) could be dW o Provided by IHSNot for ResaleNo reproduction or net
21、working permitted without license from IHS-,-,-. . 6 N.A.C.A. Technical.Note N.o. 703 represented by an empirical .equation. The equation is dC d 0 . . The values of - c:; ) given in figure 12 may be 0 : represented fairly accurately, for “angles of attack below the stall, by the following empirical
22、 equafrons: - -. - For the wing without flaps, Y cdC - d$ o = 0.012 CD - 0.00011 r. and, for the.: o to incr.ease the effect o-f swsep- back on , and to produce no change in 0 0 . for a given value of CL, - 3. Tapering the wings decreas.es . (2 ), and I cdCy d0 with no appreciable effect on 4. Incre
23、asingthe.sweepback Increases the effect of and of dihedral on . 0 0 5. A change in airfoil section is believed to have 1 little effect on - cy) 1 0 for aglven value of CL. Langley MembrialAeronaut,%cel Laboratory; National Advisory Committee for Aeronautics, Langley Field, Va., March2, 1939. , Provi
24、ded by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-N.A.C.A. Technical Note No. 703 9 REFERENCES 1. Zimmerman, Charles H.: An Analysis of Lateral Stability fn Power-Off Flight with Charts for Use in Design. T.R. No, 589, N.A.C.A., 1937. 2. Shortal, Joseph A.:
25、 Effect of Tip Shape and Dihedral on Lateral-Stability Characteristics. P.R. No. 548, - - N.B.C.A., 1935. 3. Pearson, Henry A., and Jones, Robert T.: Theoretical Stability and Control Characteristics of Wings wfth Various Amounts of Taper and Twist. T.R. No. 635, N.A.C.A., 1938. 4. Wenzinger, Carl J
26、., and Harris, Thomas A.: Wind-Tunnel Investigation of an N.A.C.A. 23012 Airfoil with Vari- ous Arrangements of Slotted Flaps. T.R. No. 664, Y N.A.C.A., 1939. 5. Harris, Thomas A.: The 7 by 10 Foot Wind Tunnel of the National Advisory Committee for Aeronautics. T.R. No. 412, N.A.C.A., 1931. Provided
27、 by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-N.A.C.A. Technical Note No. 703 C 49 = 30“ I , 10“ r* -L + ;15“ h,4.750 _- -I Fig.1 Note: A and B are quad- rants of similar ellipses, Qure l.- Plan and elevation drawings of the N.A.C.A. 23012 wings. Provided
28、by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-? , , L i 7 ! ! 1 _!. o8.-8qhofrtrpsnd+ing ontba Imhnce In the 7-blO-foot wiad Ml. split flap ddlectod. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-P.A.O.A.
29、Tsohnlod Pate PO. 703 Tipa. 3,4,5,6 .$ _:_ 3 -.a f a.0 -0 1.6 .6 -8 0 8 - a4 .e g .40 a ii % .a o I. Anglo of rttaok, u .deg. rigure 3.- Aerodo ohmMteri*tlo or rectangular P.A.O.A. ama rmsb-tip tiw. Angle Of attack, a ,dag. FQUre 4.- Aor- oh%?roterimtio Of 881 tapsred P.A.O.A. rounded-tip ring. A-14
30、.00“ r+ 4 . c -.4 I I I I 1. I I I I -a A .Ol 0 ii g d 0 Y 8 g -.Ol 1 2 2 -.oa +- 5 o-10 o-u -.OS o-1* b-m -.OL 1 I I f I - -6 0 6 A 4, 00 (b) rr 60; 4, 0 -v-s -L-lo - i5 -yI -a0 I I I, , , I I I , , ( , , , , I I , , , , , , I -.Oa I I I I 1 I -6 0 5 10 16 a- 0 6 10 16 . (0) rr 00; 6f.800 An 4, W N
31、gor* 7.- Vrrlrtlon of lollin A, 14.00 c - - 1 m-c A I I I 4 0 8 ryla oyattaok: 0 8 d (0) Sri trprrrd; A, 4.76O (d)S%aezd; A, -4.750 1 - I Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I.A.O.A. 00hd0rl x0t0 IO. 703 ngm. 100, f, 11,1a -_- 0 -2=-, m s
32、 so $ - e - - - I a I 3:ltap.eF; A, 4.760 _. 0 3:1tp&; A, 14.00 % -.001 I I I I P d I I # -.ool -8 lag10 :f .ttu& .de& l6 r1gtIre il.- ?&to of ohango of yarrlng-mmsnt 9 oorffioient with srrgle of attaok L zuo yu. I.A.O.A. 23018 rounded-tip ringa. .OlI I I I 1 I I I I t d t , -8 -1s o! attaok, z ,dag. ls Tlgure la.- Rat0 of oml&l of lrtolal-foroc oaeffioiant with angle Of attook at ouo y.1. 1.A.O.A. as012 muruhd41p mbga. , i _ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
