1、 -C-.-v STRAIGIJT EOCUMENT FILE l c : 12 Ail!; jggg* NATIONAL ADVISOR:! - COMMITTEE FOR AERONAUTICS * TECHNICAL NOTE No. 1674 ., .- ESTIMATION OF EFFECTIVENESS OF FLAP-TYPE CONTROLS ON SWEPTBACK WINGS L By John G. Lowry and Leslie E. Schneiter Langley Aeronautical Uboratory Langley Field, Va. Washi
2、ngton August 2948 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NKLICNALADVISORYC FOR AERONACTICS . TECHNICAL NOTE NO. 1674 ESTIMAIION OF EFFECZKENESS OF FlXWI!YPE CONTROIS ON SVEPTBACKWINGS By John G. Lowry and Leslie E. Shneiter An analyie has be
3、en made .af the lowwpeed lift, roIMng, and pitching characteristics of flaptype controls on a series of swept- back wings, and methods are presented for estimating these characteristics; The methods developed are essentially modifications of the exfeting me-s similar to those already ti existence fo
4、r unswept tinge (references 1 to 81, which allow for the prediction of control+urface characteristics within small limits. At the present time information on the behavior of controls in the traneonic speed range is too meager to permit the depelopment of a rationappliee at tr-onic speeds; hence, the
5、 design of control surfaces for.traneonic airplanes must still be based primarily on lo-peed considerations. A summary of the results of several low-peed wind-tunnel Fnveeti- gatione of control effectiveness on sweptback wings (data obtained in the Langley 300 MPH 7- by lC-foot tun panel represents
6、a Wang that would be obtained if the swept wing were rotated about the midpoint of the root chord until the S tip is cut off parallel to the plane of eymnetry. The chords in this case sre measured perpendiculer to the 5O-percent-chord line. All primed values refer to the knswept“ wing. CL wing lift
7、coefficient (L/qS where L is lift of ccmplete WFng or twice lift of eemiepan wing) cz c, section lift coefficient wing pitch- t-coefficient (M/q% where M is pitching moment of complete wing or twice pitch- moment of semi- span =W3) . cm % section pitohm n-t coeffioient rollinna.uen coefficient (L/qS
8、b where L is rolling mcment produced by deflection of one aileron an a complete wing) s area ofoomglete wing b span of ccxuplete wing, measured on a ldne perpendiculex to model plane of symmetry bf span of flap, measured on a 1Ine perpendicular to wing plane of symmetry .- C c ce wkgmeanaerodynamic
9、chord wing local chord, measured in planee*pareJlel to model plane of symmetry chord of flap, measured in planes parUe to wing plane of symmetm wing root chord Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA TN No. 1674 3 x Y yi YO d . A 9 P V a
10、 6 A ct/- EL =2 =3 M a R w3ng taper ratio (Wing tip chord/Wing root chord) I lateral distance from plane of eyumketry lateral distance from plane of symmetry to inboard end of flap lateral. dietsnce from plane of symmetry to outboard end of fla;p distance from center of pressure of incremental lift
11、load to mane that is, there was a decrease in C hence, the effective value of q at Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-6 NACA TN No. 1674 constant free-stresm velocity varies as CO the aspect-ratio correctian factor Kl can be obtained fro
12、m figure 6 and is the ratio of Cl/ the tapexatio correction factor E;2 ten be obtained frcm figme 6 end is the ratio of the value of C the , flap effectiveness pammeter a6 is given in figure 7 end is based on the “unswept“ flap chord ratio; and A is the sweep of the wing leading edge. .-. from the a
13、veraged curve in figure 5. values of Cl/ hence, the curves of C2/f that is, the value of s at each spauwise station was divided by cos2A and c of the “unswept“ control. Thi8 reductFon.brought all the data in;b general agreement except for the tzmxXll span controls m the 51.3 swept wing which again s
14、howed a loss in lifting effectiveness. An averaged curve of %/+j is presented in figure 8. The values of cr, may be ccmputed for w3ngs of other sweep sngles, aspect ratios, and flap spans by the formula %K3 cos2A The vahe of is obtained from figure 8 (the subscript u indicates the velue of w % for a
15、 wing of aspect ratio 6.00 and taper ratio 0.5); the flap effectivenessparsmeter cs is obtained from figure 7; eznd the aspect-ratio correctian Factor K3 is obtained from figure 9. The aspect-rratio correction factor. K3 is the ratio of the slope of the lift curve % of the “unswept“ wing to the slop
16、e of the lift curve for a wing of aspect ratio 6.00. The dataused ti calculating this curve were obtained from complete models and isolated wings in the Laugley 7- by U. - -. .- ._ - _ ._ . . _ -. - -./_ ii ._ - . . - . .-_- .I - _ ._. .cc-_. _ .- -._. _“_ _-. _.- - -*- - Provided by IHSNot for Resa
17、leNo reproduction or networking permitted without license from IHS-,-,-NMA TN ND. 1674 17 , I . . . t , b : . 5; - Figure 4.- Effect of sweep, aspect ratio, and span of - on pitching effectiveness parameter. = 0.99. control a J-b Figure 5.- Variation of theoretical yJ experimental values . Provided
18、by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Figure 6.- Aspect-ratlo and taper-ratio correction Figure 7.- Variation of flap effectiveness parameter t- factors for calculatbg Cz 8 Icurves calculated with flap chord. (Data from reference 3.) 3 from data in
19、reference 2.) - 6 .I . r Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA TN No. 1674 . . - . r . - 0 -0 .2 .4 .6 .8 . Eoof b/L Figure 8.- Variation of experimental values of with flap span b/Z = 1.00, K3 cosh. 0 2 4 6 8 /o Aspecf ruf/o of %nswep
20、fl;u/ng, A Figure 9.- .Aspect-ratio correction factor for calculating CL . 6 (Curve based on data obtained from the Langley 7- by lo-foot tunnel.) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-80 60 40 20 u?swepf-f/ap chord = &- Unswept wmg chord c
21、g Figure lO.- Vaxkttin of center of pressure of Figure ll.- Sample section lift and section pitching- incremental load with flap chord. (Data from moment coefficient distributions for a partial- references 8 to 11.) span flap on a swept wing. .Ol 0 -m pressure Provided by IHSNot for ResaleNo reprodu
22、ction or networking permitted without license from IHS-,-,-. . . . Esfmafed CL 8 Figure 12.- Comparison of experimentally determined values of lift effectiveness parameter CL with 6 values determined by method L (Symbols refer to models listed in table L) FIgwe 13.- Comparison of experimentally dete
23、rmined values of rolling effectiveness parameter Cl6 with values determined by method I. (Symbols refer to models listed in table I.1 . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Eshmated C % Figure 14.- Comparison of experimentally determined v
24、alues of Uft effectiveness parameter CL 6 with valuei determined by method It. (Symbols refer to models listed in table I. Flagged symbols indicate comparison of estimated values with faked curves of fig. 3.) . . Eailmated Czs Figure 15.- Comparison of experimeqtally determined values of rolling eff
25、ectiveness parameter Ct 6 with values determined by method II. (Symbols refer to models Listed in table I. Flagged symbols indicate comparison of estimated values with faired curves of fig. 2.) . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA T
26、N No. 1674 23 Figure 16.- Comparison of experimentally determined values of pitching effectiveness parameter Cm6 with values determined by method II. (Symbols refer to models listed in table I. Flagged symbols indicate comparison of estimated values with faired curves of fig. 4.) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
