1、FOR AERONAUTICSTECHNICAL NOTE 3481WIND -TUNNEL INVESTIGATIONAT LOW SPEED OF EFFECT OF SIZE AND POSiTION OF CLOSED AIRDUCTS ON STATIC LONGITUDINAL AND STATIC LATERAL STABILITYCHARACTERMTICS OF UTHWEPT-I!JHDWING MODELS HAVINGWINGS OF ASPECT RATIO 2,4, AND 6By Byron M. Jaquet and James L. WilliamsLangl
2、ey Aeronautical.LaboratoryLangley Field,VaWashingtonSeptember 1955Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TECHLIBRARYKAFB,NMIFNATIONAL ADVISORY COMMITTEE.llilulllullllllllulllli-FOR AERONAUTICtlUbh5b0mCBNICAL NOm 3481WIND-TUNNEL INVESTIGATION
3、AT LOW SPEED OF EFFECT OF SIZE AND POSITION OF CIOSED AIRDUCTS ON smc LONGITUDINAL AND STATIC LATERAL STABILITYCHARACTERISTICS OF UNSWEFT-MIDWING MODELS HAVINGWINGS OF ASPECT RATIO 2,By Byron M. Jaquet and JsmEsSUMMARY*4, AND6L. Will the derivative CyP and the rate of change ofCz with a generally be
4、come more nqgative as the duct size is increased.PAt high angles of attack, CyP generally becomes considerablymore nega-tive and C generally becomes less negative when the ducts sre%added, altho the effectsangle-of-attackrange.Comparison of EffectStatic Lateralof the ducts are somewhat erratic in th
5、isof Horizontal and Vertical Ducts onCharacteristics of Model WithWing of Aspect Ratio 2Directional stability.- In contrast to a small stabilizing effect ofthe addition of and increase in size of the horizontal ducts, ths additionof and increase in size of the vertical ducts on the model with a wing
6、 ofaspect ratio 2 results in a large decrease in directional stability(increaseininstability for wing-fuselage coribinations).This cubeseen in figures 15 to 18 and in figures 24 agd 25. In contrastwith thehorizontal ducts, the increments in C% due to the vertical ducts aremore nearly constant with a
7、ngle of attack. Throughout the angle-of-attackrange,by theof theat lowattackthe contribution of the various tail assenibliesto Cn is reduced$addition of the vertical ducts to the model, whereas the additionhorizontal.ductshad little effect on the”tail contributionto CnPangles of attack arida stabili
8、zing effect at moderate angles of(figs. 22(a) and 22(b).It is of interest to note that, with the large vertical duct (duct 3)on the model, directional stability is-obtained at a = 0 only when thehorizontal tail is in the high position (figs. 15 to 18 and 24). Thehorizontal tail in this position has
9、a large favorable end-plate effecton the contribution of the vertical tail toc caused by the large duct is equivalent%area by about two-thirds (fig. 24).C%“ Also, the increment into reducing the vertical-tail.-“Provided by IHSNot for ResaleNo reproduction or networking permitted without license from
10、 IHS-,-,-NACA TN 3481. Lateral-force and effective-dihedralparamster.- As would beexpected, the addition of and the increase in size of the vertical ducti* on the model caused increases in Cy for most of the angle-of-attackBto 18). lhe vertical ducts, like the horizontal ducts, had only a smalleffec
11、t on Cz at low angles of attack, and at high angles of attack thePeffects of the vertical and horizontal ducts were similar.CONCLUSIONSA wind-tunnel investigation at low speed made to determine theeffects of size of closed horizontal and vertical air ducts (wing-rootand top and bottom fuselage ducts
12、, respectively) on the static longi-tudinal and static lateral stability characteristics of unswept+nidwing. models having wings of aspect ratio 2, 4, and 6 has indicated thefollowing conclusions:1. In the low angle-of-attack range, the addition of and increase insize of horizontal ducts on model co
13、nfigurations employing an unswept wingof aspect ratio 2 resulted in a krge forward movement of the aerodynamiccenter regardless of the vertical location of the horizontal tail. Whenthe aspect ratio of the wing was increased from 2 to 6 this effect becamemore pronounced. In contrast to this effect of
14、 the horizontal ducts, theaddition of and increase in size of vertical ducts on model configurationsemploylng the wing of aspect ratio 2 produced a slight rearward movementof the aerodynamic center.2. Regardless of the aspect ratio of the wing, the addition of andincrease in size of the horizontal d
15、ucts caused an increase in directionalstability of complete models or a decrease in instability for tail-offconfigurationsat low and moderate angles of attack. The addition of andincrease in size of the vertical ducts on the models with the wing ofaspect ratio 2, however, resulted in large decreases
16、 in directional sta-bility which were about constant fQr the angle-of-attack rsmgeinvestigated.Langley Aeronautical Laboratory,National Advisory Committee for Aeronautics,Langley Field, Vs., June 16, 1955.-.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS
17、-,-,-12 NACA TN 3481REFERENCES .1. Campbell, John P., and McKinney, Marion O.: Smmary eof Methods forCalculating Dynamic Lateral Stability emd Response and for Esti-mating Lateral Stability Derivatives. NACA Rep. 1098, 1952.(SupersedesNACA 2409.)2. Bird, JohnD., Jaquet, BwonM., and Cowan, JohnW.: Ef
18、fect of Fuse-lage and Tail Surfaces on Low-Speed Yawing Characteristicsof aSwept-WingModel As Determined in Curved-Flow Test Section of theLangley Stability Tunnel. NACA TN 23, 1951. (SupersedesNACARM L$G13.)3. Silverstein, Abe, and White, James A.: Wind-Tunnel InterferenceWithParticular Reference t
19、o Off-Center Positions of the Wing smd to theDownwash at the Tail. NACA Rep. 547, 1936.4. Gillis, Clarence L., Polhamus, Edward C., and Gray, Joseph L., Jr.:Charts for Determining Jet-Boundary Corrections for Complete Modelsin 7- by 10-Foot Closed Rectsmgular Wind Tunnels. NACAWR L-123,1945. (Former
20、lyNACAARRL5G31. ).Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA TN xl. TABLE I.- DIMENSIONS OF MODEL. Fuselage:Length, ft . . . . . . . . . . . . . . . . . . . . . . . . . . 3.75Fineness ratio . . . . . . . . . . . . . . . . . . . . . . . . 7.
21、50wings :Aspect ratio, Av . . . . . . . . . . . .Taper ratio,2.2503.6750.6250.765. . 2.02. . 0.6. . . 65Ao;. . 0.150a71 . 0.825. . 1.392. . 0.418. . 0.512. . 4. . 0.6. . 0. . 0. . 0. . . 65Ao$. . 0.200. . 1.342. . 1.392. . 0.343. . 0.419- -Provided by IHSNot for ResaleNo reproduction or networking p
22、ermitted without license from IHS-,-,-14 NACA TN 3481TABLE II.- DIMENSIONS OF DUC IN INC13ESL d-+tDuct 1 I Duct 2 I Duct 3tielage Rstation F d,e13.50 2.7716.00 2.9618.00 3.0019.00 3,*QO22.00 2.9724.oQ 2.9326.00 2.8728.00 2.79.oo 2.7032.00 2.634.00 2.4736.00 2.3338.25 2.162.773.063.253.253.253.253.25
23、3.082.902.7;2.552.Y2.162.772.892.782.7312.70,2.6132.612.562.512.482.412.322.16fRDlef RDef RDo.17 0.64 E:;.47 1.13 2.39.52 1.25 2.24.55 1.25 2:20.60 1.27 2.14.64 1.20 2.20u.521.122 .23.39 3.002.28.25 .772.35.14 .352.34.06 .302.3000 2.160 0 2.77.31 1.09 2.54.86 1.82 1.661.01 2.00 1.201.05 2.00 1*IZ1.1
24、1 2.00 1.021.05 1.85 1.41.85 1.68 1.67.62 1.45 1.92.X 1.12 2.15.21 .80 2.24.08 .41 2.280 0 2.160.521.592.052.132.231.841.41.98.58.31.10001.522.502.752.752.752.502.241.901.471.05.520.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-# *R9Wrve d l=.,Fra
25、l.- Stabill BYSti Of axes. Arrow Indicatepomltlva directionof forces,mmwmta, and angular displacements.GProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4=-+=3 1-1+-+-.- lam t I pf ,IMG /.- -t 2I-t-hmmmdnm$m?a 1,iii=-= U J-525 /4.50 $ “” 1 L ;, ,.-.=_
26、-= - -=- - - - -=,-= - Low hmaaww. -(a)Horizontalducts.I?lgure2.- General srrangemnt of mdels. Dhnsions are in inches. “Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-/ /-._=-.-.- -Y-=-. , .(b)Verticalducts on model with wing of aspect ratio 2.Figur
27、e 2.- Concluded.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-L-82965(a) Small ducts on configuration 2L.L-82955L-J32967(c) Large ducts on configuration L.Figure 3.- otoaphs of horizontal ducts on mcdel having - or PeCt ratio p.Provided by IHSNot f
28、or ResaleNo reproduction or networking permitted without license from IHS-,-,-# *.4dcqdJq(a) Configu.ration FW2.Figure 4.- l%fect of hoizontalah ducts onarrangcmetahating anthe variation of CL, , and Cm with a for modelunsweptwing of aspect ratio 2.Provided by IHSNot for ResaleNo reproduction or net
29、working permitted without license from IHS-,-,-(C) (h3fi6U%tfon2JJ (d)Figure k.- Concluded.E62Jo. ,Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-1 ,.&#&* G*(a) Configuration FW4.Figure .- Hfect of horizontal air ductsarrangementshaving872Jom.#mYcz,
30、5q7(b) Coofiguratl.on FW4V.on the variation of CL,am unswept wing of aspect762Jo$, and & with a iormodelratio 4. IvP .,“.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-(c),Awb&mit,Lqd4ConfqglraticnlruNE7-52Fw4v& (d)Figure 5.- Concluded.3,configurati
31、on.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-, # I ./l&f*c,*(EL) cOII,fWRlih3116.Figure 6.- Effect of horizontal air ducts=Wements havingonaum.#oHd/cGab9(b) Configuration FW6V.the variationor CL, , and Cm with a for modelunswept wing of awpect
32、ratio 6.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-OJII3figure 6.- Conchded.r ,? ,., ,1Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-, , , ,Figure 7.-.4*0f E,*(a) Horizontal. air duct6.!4L?w 8&
33、.a1!.7.6 6ue se.2 410 3gn? 21.2 0$.,101!-J,1 a-$-404812 1620242832mdw,dg(b) Vertical air ducts.IWfect of horizontal amd vertical air ducts on the variation of CL, , and Cm with ufor configuration FW. GProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-6
34、.?PJc-nmdm(a) Horizontal air ducts .“.4L&(b) VertiCd air ducts.Figure 8.- Effect of horizontal and vertical air ducts on the vexiation of CL, , and Cm with afor configuration FW2V., i, ,1lb, ,I ,1 188 1, IllProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS
35、-,-,-* .4wbtiqcq*(a) Horizontal air ducts.Figure 9.- Effect of horizonw,.411z!?6f&(b) Vertical air ducts.and vertical air ducts on the”variation of CL, CD, and with uProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-“-404at2 1620242s 92mdm=,m(a)Jiorizo
36、ntalairFigure 10.- Effect of. *1horizontalduct6 .and.4#gh?dama,tr#d?9(b) Vertical air ducts.verticalair ducts on the variation of CL, CD, d Cmfor cotiiwation 2H., , ,1 1 1, 1! JProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-WGMG*(a) Configuration FW2.Figure 11.- EPfect of horzontal airarrangements1 ,. ,#Addet.G*(b) ConfuratiOnFW2V.ducts on the vaxiation of CYP, CZP, and Cnp with a for delhaving an unswept wing of aspect ratio 2.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
