Low-speed Wind-tunnel Tests on a Model of a Jet Tailless Aircraft

Transcription

1 RO \! i L A"; " "....,..,~,.'-, 1 t r-,'" ~",. '.,' :...:' \,"..] ,.,< 11",)... ~ "~... a~ BE:.Cf':'-ORCJ.. R. & M. N (10,616) A.RC. Technical Reprt MNSTRY OF SUPPLY AERONAUTCAL RESEARCH COUNCL REPORTS AND MEMORANDA Lw-speed Wind-tunnel Tests n a Mdel f a Jet Tailless Aircraft By J. TRuNcER, M.A., and G. F. Mss, B.Se. Crwn Cpyright Reserved LONDON: HER MAJESTY'S STATONERY OFFCE 1956 P RC E 9s 6d NET

2 Lw-speed Wind-tunnel Tests n a Mdel f a Jet Tailless Aircraft By J. TROUNCER, M.A., and G. F. Mss, B.Sc. COMMUNCATED BY THE PRNCPAL DRECTOR OF SCENTFC RESEARCH (AR), MNSTRY OF SUPPLY Reprts and Memranda N.2 843* January, 1947 Summary.-This reprt gives the results f lngitudinal and lateral stability tests made n a mdel f a jet tailless aircraft. t includes the effects f split flaps, trimming flaps, dive-recvery flaps and fur types f anti-tip-stalling device (slats, nse flaps, duble split flaps and letter-bx slts). t als includes the effect f the grund in the landing cnditin. 1. ntrd~tctin.-wind-tunnel tests were required t assist in the design f a jet-prpelled tailless aircraft. The tests cvered the standard lngitudinal and lateral measurements, tgether with sme research int the prblems f flap design and the best type f anti-tip-stalling device. This reprt gives an accunt f the prgramme cvered and full tables f the results. 2. Details f Tests.-The tests were made between Nvember, 1945, and May, 1946, in the N.1, llt-ft Wind Tunnel at the Ryal Aircraft Establishment. The majrity f the measurements were made at a wind speed f 120 ft/sec, giving a Reynlds number, based n mean chrd, f 1 28 X 10 6 ; but a few tests were als made at 180 ft/sec (R = 1 93 X 10 6 ) t check the Reynlds number effect. The mdel used fr the tests was a l/s-scale mdel n which the air-intake ducts were crrectly represented as far as the engine and then cnverged t frm a single duct which cntinued t the rear f the fuselage. The mdel was fitted with elevns, trimming flaps, split flaps and dive-recvery flaps and als had a remvable leading edge s that it culd be tested with and withut fixed letter-bx slts. A wire f 24 standard wire gauge was fitted arund the nse f the mdel t fix the bdy transitin. A general arrangement drawing f the mdel is given in Fig. 1 and the mdel dimensins in Table 1. All pitching-mment cefficients are given relative t the wing mean quarter-chrd pint. * R.A.E. Reprt Aer. 2181, received 19th May,

3 3. Results Lijt, Lngitudinal Stability and Trim Flaps up (Table 2, Fig. 3).-ln the basic cnditin with flaps up and n anti-tip-stalling devices fitted the aircraft develps a tip stall at a trimmed lift cefficient f 0 67 at R = 1 28 X 10 (Fig. 3). The stall is delayed t C L = 0 77 at R = 1 94 X 10 6 (Table 2) and there will clearly be a large scale effect n this and n maximum lift. The curves fr n; = deg, -15 deg, -20 deg and -25 deg in Fig. 3* have been cnstructed frm the elevn pwer measurements given in Table 11. The neutral pint ver the range 0 < Cr. <0 6 is at h.; = Since the c.g. range f the aircraft is frm 0 14 t 0 29 f the mean chrd this gives a static margin at R = 1 28 X lor. f O'04 in the aft c.g. psitin. The nrmal c.g. f the aircraft is at O 24c. Tests made with the duct entries pen and clsed] shwed that the nly change was n maximum lift cefficient which was O 05 greater in the clsed cnditin. Surface tufting shwed that this increase was due t the eliminatin f a stall which develped frm the entry lip in the pen cnditin. unless therwise stated the tests described in this reprt were all made with the duct entries pen Effect j split jlaps (Table 3. Figs. 4 and 5).-The split flaps designed fr this aircraft; gave n change in neutral pint but caused a large negative change in trim (.1C: 1 flaps = at C L = 0 5). Tw methds f reducing this change in trim were tried:- (a) by mving the flap hinge-line frward by an amunt equal t the flap chrd (b) by reducing the flap chrd t apprximately half the design value (see Fig. 1). The results n lift and pitching mment are summarised belw and pltted, fr an elevn angle f -10 deg, in Figs. 4 and 5. Type f split flap Large-chrd flaps hinged in rear psitin LlC L LlC.~lef.j ACMe,.j (rx = ~ deg) i (CL = 0"5) 0.()8~ () 048 lj l~ Large-chrd flaps hinged in frward psitin () 28 () (J39 ().()(J(-l lj ()4 Small-chrd flaps hinged in rear psitin () U-()5S O (J31 ().1O The lift increases given abve are the untrimmed values. Althugh the frward psitin f flap gave gd results at lw incidences, there was a large drp in lift ver the stall with this arrangement. A few measurements made with the flaps hinged in the rear psitin at the inbard end and set perpendicular t the wind acrss the wing shwed a similar lss in lift at high incidences, the pitching-mment curve in this cnditin being almst identical t that with the flaps hinged frward. Halving the flap chrd reduced the change f trim and lift increment due t the flaps by ~)5 per cent ver the whle incidence range. * 1)!V is the value f the elevn angle measured alng wind. t n the clsed cnd.itin the entries were faired ver t give the 'datum wing' leading edge shwn in Fig. 1. 1: Large chrd flaps hinged in the rear psitin, see Fig. 1 and Table 1. 2

4 As there were structural difficulties assciated with mving the flap frward n the full-scale aircraft the smaller-chrd flap was recmmended and all subsequent tests were made with this type f flap. The maximum trimmed lift cefficient in this cnditin is C L = 0 94 (R = 1 28 X 10 6 ), with instability setting in at C L = 0 78 (Fig. 5) Effect f trimming flaps (Tables 2 and 3. Figs. 6, 7 and 8).-n the riginal design a trimming flap was incrprated which extended inbard frm the elevn (see Fig. 1). This was designed t be deflected t small negative angles when the split flaps were dwn and it was hped that this might prvide the necessary change in trim withut unduly affecting the lift due t the flaps. n fact, as Figs. 6, 7 and 8 shw, the trimming flaps gave, in cmparisn with the elevns, a large change in lift and nly a relatively small change in trim. t was als fund that the effects f the trimming flaps were reduced t less than ne-half n pening the split flaps. T investigate this pint further, sme tests were made with the split flaps raised ff the wing by 1/3 f the flap chrd t allw the air free passage ver the trimming flap. Althugh this increased the efficiency f the trimming flaps, the raising f the split flaps caused a further negative change in trim and there was little net gain. Fr the results given in Figs. 6, 7 and 8 and except where specifically stated t the cntrary in the tables* the split-flap angle was fixed relative t the wing and did nt mve when the trimming flap was raised Effect f dive-recvery flaps (Table 4. Fig. 9).-The dive-recvery flaps shwn in Fig. 1 were fund t give a negative pitching mment instead f the required psitive increment. At C L = 0,,1ef = but this reduced t,1c M = 0 by C L = 0 6 (Fig. 9). A reductin f the flap span was fund t have n effect. A single measurement was taken with the flaps mved back frm their design psitin at 0 77c t 0 40c but, as the pitching mment lay n the riginal curve with flaps up n further tests were made Tests with grund represented (Table 6. Fig. lo).-t cver the landing cnditin sme tests were made with the grund represented. Fr these the mdel was fitted with 74 per cent span slats and suspended s that the jet exit was just clear f the grund at an incidence f 20 deg. Fig. 10 gives a cmparisn f the results with and withut grund and shws that the grund effect was relatively small. t caused a psitive change f trim (,1 C M === 0 01 with elevns at deg) and tended t destabilize the aircraft at high incidences with flaps dwn, but bth these effects became less as negative elevn was applied Anti-Tip-Stalling Devices (Tables 5 t 9).-One f the fremst prblems assciated with all swept-back wings is t find a satisfactry methd f curing the tip-stalling tendencies at lw speeds withut detracting t much frm the high-speed qualities f the wing. On this mdel fur types f anti-stalling device were tested, namely:- * Viz. in Tables 6 and 10. 3

5 (a) (b) (c) (d) Handley Page slats nse flaps duble split flaps letter-bx slts. The effect f (a), (b) and (c) have been discussed already in Ref. 1, but, as n tables f results were given, these have been included in the present reprt. Sme further tests were als made besides thse recrded in Ref. 1 and the results f these are given briefly belw Cnstant-chrd nse flaps (Table 7B).-The nse flaps described in Ref. 1 were tapered flaps f chrd equal t 10 per cent f the lcal wing chrd. Tests made with a SO per cent span nse flap f cnstant chrd equal t 0 83 ft full-scale? gave almst identical results t thse made with the tapered nse flap f the same span. ~ Small-chrd duble split flaps (Table 8R. Fig. 11).-The duble split flaps f Ref. 1 cvered 2/3 f the elevn chrd (see Fig. 2b). Sme smaller flaps f nly js f the devn chrd were als tested and Fig. 11 gives a cmparisn f the effects btained with the tw sizes f flap. t will be seen that the smaller flaps were less favurable as they gave instability near the stall, thugh this was reduced when negative elevn was applied. Als the slpe f the pitching-mment curves at lwer lift cefficients was as excessive with the small flaps as with the large, thugh there was less change f trim Letter-bx slts (Tables 9A and 9B. Fig. 12).-Fig. 2a gives sectins f the letter-bx slts tested and the results fr the varius slt spans are given in Table 9A. t was fund that the results varied nly slightly with change f span and in n case was the tip stall cured. t was thught that this might be due t the rather small gap f the riginal design (apprx. 1 per cent f the chrd) and further tests were therefre made with a mdified slt which had a gap f 2 per cent f the chrd (Table 9R). Fig. 12 gives the results with the tw types f slt and shws that the increase in slt gap gave n imprvement ver the riginal design Prfile drags (Fig. 13).-The increases in prfile drag due t the fitting f anti-tipstalling devices were nt given in Ref. 1, but frm an imprtant factr n an aircraft designed specifically fr high speed. Fig. 13 gives prfile-drag cmparisns at an elevn angle f -10 deg, shwing the effect f pening slats, nse flaps r duble split flaps n this mdel. At small lift cefficients the increase in prfile-drag cefficient due t slats r nse flaps was abut ().ns but, abve C, 0 5, it became negative because f the eliminatin f the tip stall. The drag figures with nse flap have been crrected by the aid f Table 2 t allw fr the fact that the duct entries were dsed in this case. Fig. 1~3 shws clearly the large drag increases which were caused by the duble split flaps even at lift cefficients greater than (- s. * This gives a nse-flap chrd.wing chrd rati f 20 4 per cent at the tip and 9 6 per cent inbard. 4

6 3.3. Lateral and Directinal Stability (Table 10. Figs. 14 t 18).-'n all the lateral tests, measurements were made at psitive and negative angles f sideslip. At lw incidences the curves btained were symmetrical, and the values at psitive and negative angles f sideslip have been meaned and the derivatives taken ver the range f3 = ± 2 5 deg. The values f nv, l; and Yv btained are pltted in Figs. 14, 15 and 16. Abve X = 9'85 deg the yawing-mment curves became unsymmetrical, and unstable at sme angles f yaw, as shwn in Fig. 17. The side-frce curves were similarly affected but the changes in rlling mment were cmparatively slight. Detailed tests made n a 45-deg swept-back wing f aspect rati 3 0 and taper rati 4 : 1 (Mdel B, Ref. 2) have since shwn that this type f yawing-mment curve is liable t ccur n any swept-back wing at incidences near the tip-stalling incidence, t is due t transitin frm a symmetrical curve t ne f tw alternative subsidiary 'lps' which can be btained if ne r the ther wing tip is caused t stall prematurely. On this particular mdel the accumulative errrs in the mdel and the tunnel flw caused a tendency fr the prt wing t stall first, as is shwn by the large negative yawing mments at f3 = 0 deg (Fig. 17). The nly means f eliminating the risk f such directinal instability is t delay the tip stall by sme means. Fig. 18 shws hw the curves were imprved by fitting the 37 per cent span slats. n this case there was nly slight asymmetry at the highest incidences and up t X = 15 deg the curves were straight and symmetrical. The fin effect n n; and Yv was as fllws:- Lln, (fin) = O 04 Llyv (fin) = Cntrls Elevn pwer (Table 11. Figs. 16, 17 and 18).-Elevn pwer was measured ver a range f incidence n the plain wing, flaps 0 deg, and at the highest incidence with 74 per cent span slats fitted. The results are given in Table 11 and the increments f pitching mment, yawing mment and rlling mment are pltted in Figs. 16, 17 and 18. There was a steady decrease in elevn effectiveness as the angle f attack was increased and this was nly partly restred by pening the slats (Fig. 16). The fllwing table gives the rlling mment and adverse yawing mment prduced by elevn mvements f ± 15 deg frm their psitin fr trimmed flight at varius lift cefficients , C L trimmed Prt elevn 15 deg dwn l frm trimmed Starbard elevn 15 deg up J psitin ' LlC" 10_ 3 1_C _ N slats With 74 per cent span slats -0,1-0,5-4, ,

7 Only at the highest incidences des the adverse yawing mment becme appreciable, and this is reduced, and the rlling mment cnsiderably increased, by pening the slats Rudder pwer (Table 12).-Rudder pwer was measured at C L = 0 05 and Table 12 gives the results n yaw and side frce fr rudder angles f 0 deg t 20 deg. The variatin with rudder angle was fund t be linear and the rudder pwer was as f11ws: L1 en = per degree f rudder angle. 10: 1 / Cy = 1 64 per degree f rudder angle. REFERENCES N. 1 J. Trunccr 2 J. Truncer Authr Title, etc. A cmparisn f the effects f slats, nse flaps and duble split flaps n a mdel f a 40-deg swept-back tailless aircraft. A.R.e June, (Unpublished). Wind-tunnel tests t investigate directinal asymmetry and instability n a swept-back wing (Mdel B, 45-deg sweepback, aspect rati 3). A.R.C. 10,489. January, (Unpublished). 6

8 living Area* Span Mean chrd Aspect rati S b c A TABLE 1 Mdel Data Scale f mdel, 115th Mdel-Scale Full-Scale sq ft sq ft 7 8 ft 39 ft ft ft 4 59 EQ symmetrical Sectin Chrd at AA 9 8 in ft at BB (4,83 ft full-scale frm centre-line) 26 in ft Sweepback f 25 per cent chrd line between AA and BB 40 deg Dihedral 0 deg Gemetric twist 0 deg Mean quarter-chrd pint psitin (n chrd-line) Distance aft f leading edge at BB in ft Elevns Span Area aft f hinge Chrd aft f hinge at AA at XX n; = elevn angle measured alng wind 1 90 ft 0 61 sq ft 3 6 in. 4 1 in ft sq ft 1 50 ft 1 71 ft Trimming flaps Span Area aft f hinge Chrd aft f hinge at XX at BB at CC 1 41ft 56 sq ft 4 1 in in in ft sq ft 1 71 ft 1 82 ft 3 70 ft Split flaps Span Angle (abut hinge-line) (alng wind) (a) Large-chrd flaps Areat Chrd at XX C, at CC c, (b) Small-chrd flaps Arear Chrd at XX c, at CC c, 1 41 ft 72 2 sq in. 4 1 in. 4 5 in sq in in in ft 60 deg 51 deg 14 sec sq ft 1 71 ft 1 88 ft 5 90 sq ft O 79 ft 0 87 ft ---~~ -~~-_ _.. * Based n prjected leading-edge and trailing-edge lines (i.e., mitting the fillet) t fuselage side, then straight acrss the centre-sectin. t This area allws fr the cut-ut which is necessary at statin BB. 7

9 TABLE -cntinued Mdel-Scale Psitin fflap hinge Fr rear psitin this is distance C, frm the wing trailing edge. Fr frward psitin this is distance 2 X C, frm the wing trailing edge. Full-Scale Dive-recvery flaps nbard prtin Angle (abut hinge-line) Outbard prtin Angle (abut hinge-line) Span Area Span Area Fin and rudder Grss area* S" per cent Sweepback f 25 per cent chrd line t vertical Fin arm (Mean quarter-chrd pint wing t mean quarter-chrd pint fin and rudder) " Vlume cefficient ftl' 5"1" Sb 4 2 in sq in. 9 7 in sq in sq ft in ft sq ft 90 deg 4 04 ft 1 96 sq ft 90 deg sq ft 48 deg ft Handle)' Page slats Span/semi-span Nse flaps Tapered: span/semi-span Cnstant chrd: span/semi-span Chrd Duble split flaps (see Fig. 2) (a) Large-chrd flaps Span/eleven span Chrd/eleven chrd Angle (abut hinge-line) (b) Small-chrd flaps Span/elevn span Chrd/eleven chrd Angle (abut hinge-line) Letter-bx slts (see Fig. 2) Design slts with gap === 1 per cent chrd Span/semi-span Revised slts with gap === 2 per cent chrd Span/semi-span O 37 and O ,0'50,0 74 and in ft O 73 and deg and 40 deg 0 61 and deg 0 18,0 29,0 48 and * Based n prjected leading-edge and trailing-edge lines t fuselage. then acrss fuselage at right-angles t fuselage datum-line. 8

10 ----~----- TABLE 2 Lift, Drag and Pitching-Mment Cefficients Flaps 0 deg Cmplete mdel. Plain wing. 'l}w Trimming flaps Y.. CL Cn c'wf/4 -_.._ v= 180 ft/sec R = 1 93 X 10 6 With duct entries blcked () ,0126, ' , ,, v= 120 ft/sec R = 1 28 X 10 6 With duct entries blcked v= , , , , , ,0526 i , , _ , , , ft/sec With duct entries pen , , i -0, , , [ i i i , ,

11 TABLE 2-cntinued 1)", Trimming flaps (X, CL C /J (cleg) ! , () ()' _! , ~ '0 ' ,

12 1 1 1 TABLE 3 Lift, Drag and Pitching-Mment Cefficients with Split Flaps at 60 deg Cmplete mdel. Plain wing. Entries pen. v = 120 ft/sec. ~~~~~~ ,----~~-; ~----- Type f split flap* 'l}w Trimming ('J. CL : CD ; CM C/~ i flaps : ' 1 1 _,. Large-chrd flaps: hinged in rear psitin Large-chrd flaps: hinged in frward psitin ' ll , , , ' ' ' Large-chrd flaps: hinged in rear psitin at inbard end and set perpendicular t wind acrss wing Small-chrdflaps:-lO 0 hinged in rear psitin i O' ' ,0222 i O'Oll ~ O Oll ,0251 ll O , , , * Fr flap chrd and flap hinge-line psitin see Table 1. t The split-flap angle was fixed relative t the wing and did nt mve when the trimming flap was raised. 11

13 TABLE 3~cntinued Tvp«f split flap* Small-chrd flaps: ltingt'd in rear psitin and raised ne-third f flap chrd abve wing f} Trimming flaps : () _-J--~=---- lot i ()'9 CL Cn ('ill e!+ () 371 ()'()621 () 001f) ()'619 0'()83H 0 () ()'17 () 04S (). 173 ()'() () 288 () ()2() () 348 ()'() ~-_._ ,_._---,.' (H) '()187 ()'531 ()'OH21 0 ()()59 () ()'()131 ()' ()'0221 ()'873 ()' () 921 ()' ()22 ()' (H1l22 * Fr flap chrd and flap hinge-line psitin see Table 1. l' The split-flap angl was fixed relative t the wing and (lid nt mve when the trimming flap was raised. TABLE 4 Lzft, Drag and Pitching-Mment Cefficients 'with Diue-Recery Flaps Open Cmplete mdel. Plain wing. Entries pen. Trimming flap 0 deg. 11u' = 0 deg. v =cc 120 ft/sec. Dive-recvery flap psitin : C L en CJ e!+ With flaps in design psitin (Hinged at O'()77c apprx.) With flaps hinged at 0 4(lc 'With reduced span flapst hinged at (l 077e Wi t h reduced span flaps hinged at () 161c 0 3 ()'021 ()'0285 () () O' 142 0'()261 ()' ()'262 ()'0276 () () ()' () () () '''._-''! '()269 S f) ()'()346 --"-' :._-.. '-'" --._ f) () 332 () ()3()8 ()'0:347, t Fr the reduced span flaps the cngth f the swept hack prtin was shrtened at the utbard end by 4 8 in. mdel-scale, i.c., 2 ft full-scale. 12

14 TABLE 5 Lift, Drag and Pitching-Mment Cefficients with Handley Page Slats Cmplete mdel. Entries pen. v = 120 ft/sec. --~---"------; ; c ~~-----c--~ Slat span frm tip --Semi-span ~-- -~~ Y/w Trimming' : flaps CD Flaps 0 deg ~ ' ! ' , ' ! , , '1-0' , , , , , ~ ! fh , ' , ' ~0' ,

15 TABLE 5-cntinued Slat span frm tip S(~mi-span 1)l' Trimming flaps X (cleg) ---_ ,-..- _..._ Flaps 60 deg (Small-chrd flaps hinged in rear 0 37' () iti PUS] rn 8 95 ()'721 () ()837 0'(J ()5 () 843 (J 106! ()'946 () , () 2() ()' , * () () 4 () 102 ()'()519 ( ()'358 ().06()4 () () () 0806 (H1l59 11 () ()' () () ()'968 (). 186 (t ()' () 990 () ,.-._ _ (). 02~~ ()' ) () ()231 ]() (Hl ().(}l (J' ()' () 951 () 242 () () ()'()633, _._ ~----_ () 778! (J () O(Jl() (J' ()' () _ _._-----_ (). 151 () 0545 (H ()'O533 ]() ()-(1790 () () ()5 ()' ()' () 920 ()'221 () () ()'O637 2() ()' n () 0487 ()'()468 :, 25 () 384 ()' () 646 ()'0776 0'() O'() () ()' () () () ()' (J' * The split flaps were fixed relative t the wing and did nt mw when the trimming flaps were raised. 14

16 TABLE 5-cntinued Slat span frm tip ----Semr-span-. 1]w Trimming flaps X CD Flaps 60 deg-cntinued () ~_ _-- _--~ ~ 10 10* ~. ~' ' g :~5 _ i :n~ ~ :~~~ '0389-0' * The split flaps were fixed relative t the wing and did nt mve when the trimming flaps were raised. 15.

17 TABLE 6 Lift, Drag and Pitching-Mment Cefficients with the Grund Represented Cmplete mdel with 74 per cent span slats. Entries pen. v = 120 ft/sec ~-----T ~- Cnditin f mdel rl w Trimming flaps X CD CM c/4 Flaps 0 dcg Flaps 60 deg relative t trimming flaps (small-chrd flaps hinged in rear psitin) () O () ,0431-0, () , , ()'138 ()' O 050S ()-(l708 O O ~ i (J.(l , () ()'0346 Flaps 60 deg relative t trimming flaps (small-chrd flaps hinged in rear psitin) - 15 () ()'978 1.() ()' ()' ()l{l8-0'0133 _,. ~,._... i ~ 2() 4 ()' J _ ()' ()' '() ()' ()' , , , , ~---- L ~_ 16

18 TABLE 6-cntinued ---~~~~ c-----;------;-----,------, Cnditin f mdel 'Y}w X Flaps 60 deg (large-chrd flaps hinged in frward psitin) _._._~_.".'. 1_'0_5_8----'-~_0_~.3~0_5 ()' ,0039-0, , n061 _ 17

19 TABLE 7A Lift, Drag and Pitching-Mment Cefficients with Nse Flaps (tapered) Cmplete mdel. Trimming flaps 0 deg. v = 120 ft/sec. Flaps 0 deg. Entries clsed* , , , ' , ~~~:_ ~:::~ - ~::~~ ~:~:~-~ ' ~-0' O , () _.._._ O '-~-_....--' _ _ ~ ~ ,8, O Flaps 0 deg. Entries pen () ' ()' , ()'0195 ()'0442 () ()'0384 ()'0456 0'() ' ,0027 ()'0161 (} , ()' ' ()(l , , , * The graphs f <d. 1 were crrected fr the sake f cmparisn t the 'entries pen' cnditin. 18

20 TABLE 7A-cntinued , ;------, _._------_ Nse flap span frm tip 'YJw X CD Cl1c/4 Semi-span ----_ _ [ Flaps 60 deg (small-chrd flaps hinged in rear psitin) Entries clsed ~-_._.._' , -0, , ! -0' _0'268_1~37_ ' , , ; --0, , -0, , , , , , , , , ()' , , , , , , , , , , , ~ _._._---~-'---'-- 19

21 ~-_ _-- ~ ~ _-----~--- TABLE 7B Lift, Drag and Pitching-Mment Cefficients with Nse Flaps (cnstant chrd) Cmplete mdel. Entries clsed. Trimming flaps 0 deg. v = 120 t/sec. --~~aps 0 d-: Nse flap span frm tip 'YJ : cc Semi-span- (de!i~), L 'D ' (HH _._--~ _._--_._ ()' (j' (j' ()'()960 Flaps G() deg (small-chrd flaps hinged in rear psitin) 0 50 () ()-() () 241 (j' () ~ ' (_)'336 ()' , () 0803 (j'0052 (j' ()' '() ()-() ()' ' _ 20

22 TABLE SA Lift, Drag and Pitching-Mment Cefficients with Duble Split Flaps (large chrd) Cmplete mdel. Entries pen. Split flaps 0 deg. V = 120 ft/sec. Trimming flaps 0 deg. Flap angle Duble split flap span upper lwer 'YJw (X. C L CD C.wC/~ : ETevnsp~- flap flap _ , ' i ,0559! ' , ' ,1413 i ' , , ' , '0524 i , ,0060 i , , -0, ' ,1237 : , -0' ' , ' , , -0, , ~ -0, ' ' , , , (Flap hinge mved ' ,0186 frward t lie alng ,0201 elevn hinge-line) , ' , , , , ! , , _._---- -~ ~----,---

23 TABLE 813 Lift, Drag and Pitching-Mment Cefficients 'with Duble Split Flaps (small chrd) Cmplete mdel. Entries pen. Split flaps 0 deg. Trimming flaps 0 deg. V = 120 ft/sec ~--~ Flap angle Duhle split flap span upper lwer }]w (X C L Cn CM 7/4 Elcvn span flap flap ---~_._ ~ () () ()'() ' () ()' () (J'278 () () (J ()'0427 0'067() ()'0541 ()' )O(l )(l HJ O 3(J4 O 064() ()' ()' (J 442 (J'0643 (J' (J.885 (J (J ().332 (J.0350! 60-~--O-----l(~-' --S:-6- --~~ ~ ~ () (). (J66S 12 8S (J'152 ()' (J ()'() HJ ()' '~' ' i 0 (J , O Gl (J' )O() (J' ()' "

24 TABLE 9A Lift, Drag and Pitching-Mment Cefficients with Original Letter-bx Slts (slt gap = chrd) 1 per cent Cmplete mdel. Entries pen. Trimming flaps 0 deg. Slt span frm tip -Semi~span--- : 'YJw = 0 deg : 1]w = -10 deg Flaps 0 deg V = 180 ft/sec , , ' , , : , ~_O 89~_1~' 336_ _ Flaps 0 deg V = 120 ft/sec i , ! ()' , '

25 TABLE 9A-cntinued Slt span frm tip S-emi~span rJ:. = 0 deg 1 1]w~~~~ de~,----- X C J, CD X Cn -1.n- _gg~ g:g:~~ _ ' ' ' ' ' ' , _ Flaps 60 Qeg (small-chrd flaps hinged in rear psitin). V = 120 ft/sec ()' ' () , ()'

26 -~~--- TABLE 9B Lift, Drag and Pitching-Mment Cefficients with lvldified Letter-bx Slts (slt gap = 2 per cent chrd) Cmplete mdel. Entries pen. Trimming flaps 0 deg. v = 120 ft/sec Slt span frm ----Semi-span tip 1}w X C L CD {deg) Cu e/4 Flaps 0 deg 0-48 () ,0385-0, Flaps 60 deg (half-chrd flaps hinged in rear psitin) () ~ ! S

27 TABLE 10 Lateral and Directinal Cefficients and Derivatives Entries pen. v = 120 t/sec. Cnditin f mdel : N slats c, (~-)---1-;-~,~ c. 103 c, l:: ~,, ~~------~--'-~---~-~----- y" Fin ff Flaps () deg 1 35 () ,29-0, , ,3 --7,8 --3,5 () 013 c-mz () ,39-0, , ,63-19,2 --8,9-4,2-0, ~ '32 5-0, , ,24-5, , r 0 ()93 ()-(l ,28-5,06-2, ()' , ()'() _ _ ()'58 10' '3 i () _._ S (l S S , () , S 53 7._-_._+._.. 26

28 13 6 0' , TABLE lo-cntinued cnditin-f mo-c:l------:-----~l ;---~~;lc, Wl C~-~~-y - ---;:- tv : N slats-cant. Fin n Flaps 0 deg , ,86 --2,86-4,90-9,12-14,05-18,73-13, ,18-5,89-0, , Fin n Flaps 60 deg (small-chrd flaps hinged in rear psitin) With 74 per cent span slats Fin ff Flaps 0 deg Fin n Flaps 0 deg ' ' , , , ' ~ , ,9-22' O 110 i ,118-0,162 ~ ~ ~ ~ ~ Fin n Flaps 60 deg 5 5' (small-chrd flaps hinged in --_...,.--._ _._-_ rear psitin) 'Y]w = 0 deg ()'()71 -- () 'Y]w = deg With 37 per cent span slats Finan Flaps 0 deg J]w = 0 deg () ()

29 _ TABLE lo-cntinued Cnditin f mdel Ct. C L {J UP C" t, With 37 per cent span slats---c01~t. Fin n Flaps 0 cleg '/7",- 0 (kg :.~ ~07 ---==-!.~_ S ()' S () , () () Fin n 11. OS Flaps 60 deg (small-chrd 2 S flaps hinged _.~--_ _ _-- -- '-' rear psitin) 15 2S n«deg S () () ~()S " ~._._-, _ m) ;) ~ 2 0S 1{) () O 175 () ()

30 Cnditin f mdel With 37 per cent span slats-cnt. Fin n Flaps 60 deg 1}w = -15 deg 1}w = -15 deg Trimming flaps --15 deg (split flaps deflecting with trimming flaps) Fin n Flaps 60 deg 1)w = -- S deg Trimming flaps deg X C L ( r, TABLE lo-cntinued ,68-2,5-3, , , , , , , ' ,77-2,5-3, ,36 --S ,82-2,5-3, , , ~- ---_.._--~-~----_.,-~ ----_..._-~ , ,1-8,15-4,1-4, '21-4,53-2,33-19, , , , ~ , '5 --5,57-28, ' -0, ,72-41,7-12, ,91-7,2 --3, ,6-28'4-14,3-42' , ,9! -14, 'yv , ,

31 38 52 TABLE 11 Elevn pwer Cmplete Mdel. Entries Open. Trimming Flaps 0 deg. v = 120 it/sec. Cnditin f mdel 1'\0 slats Flaps () deg Flaps 60 deg (small-chrd flaps hinged in rear psitin) : 1 35 ~ ~--~~-~t elev~nly ~~~~::r~ 1 ; elevens /1C,11 (j~ ~ _ 15 ()'( ()'() ()'122() 2() () () 185() ---5'-6-- -~-ls-- --~() (lg-----: ()'1(120-- ' 15 () () () O 160() 25 ()' ()' ~ , ()' () () () () () ~._' ~ ~------_._---- "-'--- ~.-.._~ ()'() ()' () () () () ~----~ ~ ~ ~ ----~ ' With 74 per cent span slats '() Flaps O deg O'()4 ()'1084 2() () () () 33 () n () ~ ~--_._---- ~ ~ -- ~ _ () 9 1 TABLE 12 Rudder Pwer Cmplete mdel. Entries pen. Trimming flaps 0 deg. Plain wing. Split flaps 0 deg. V = 120 it/sec. : (ckg) 1CL H)'l;1C" lo:jac Wli/C\- (1- ~ ~ () ()S

32 CHORD A~ON4 \A(e'N=O'---- -".. F'ORWARD Fl..AP HNGE F"'LAP HNCrE OR'C,NAL MODF"'ED SLOT SLOT FG.2a. Details f letter-bx slts.»> TRMMNC, F'LA?5 (CONTNUATO"'l 01=' E,U:'VO"'lS) " LARC,C- (;HORD FLAPS SMALL-CHORD FLAPS CHORD ~l-on WNO 57_2 D H5- CORRESPOND5 T AN AN4LE r 00 ABOUT THE \-hnc(e:. LNE SMALL- CHORD F'l.AP5 j, ree:t : rul..~ $CA~E 6 ~ Z Ft.E:T r-'100e:1.. SCA..E: 18, FG. 1. Wind-tunnel mdel. FG.2h. Details f duble split flaps.

33 .11- t>.- /},_.8 O ;+ c..., C J :""""""L-A~ 7''!_--\_...l.----_+_---_ 1-=...\i:.,St----F.l";;;:----j-----/ j j : '...---P if "1 f--- O j--=...;::.--.;-:-c---."""-= j-----! Q 4!-_---,.L-;JfL-;,L.---f-,L-----j l.-----l j N Fl.APS -6 _ 6- LARyC-CHORD F'LAP.. --x- - x - SMALL-CHORD FLAPS O' Z J..J;l;---,'---_+_--,~----j ,----1.( SEE Fe.. 1 FOR DE:TAl.S OF' Fl.APS r z 0 4 1",, 0 ~-'O;' ~ O' < F~4 8 1 F'T,' jiT.,--"..----,----, ,----:---,-----, FLAP50 e:, COEF'F'CENTS fl w = -100 t;> ',0 24 L L..-.--JL l. ----'- ---L -----! FG. 3. Pitching-mment cefficients. Flaps 0 deg. rjw = + 15 deg, -15 deg, -20 deg, --25 deg (rjw = elevn angle measured alng wind). HNC,ED N REAR POS'N HNC,E:D F'ORwARD F'l.AP560' e-.,..., 8 b "'../ :; _./f l._ --L -L. --" j ;:< --x---- SMALL-CHORD ="LAP5 1"1(,1 _ O,SL ---L..L. ----" -L ---'- _ NO x - F'LAPS LARC,E:- CHORD i F'LAPS} Flq 5. PTCHN~-1'10MENT COEffiCENTS T]w = _\00 SEE FGS. 4 and 5. Effect f split flaps.

34 r-o,----r , , , C L FLAPS 60 (SMALL CHORD FlAP5 N REAR P05N) O 8 ~w'" -O :,.Lf--:"'--7"'=-+"-;:-...-""---t---===--='-----j i C L J O L-.,L--,.,L--.'h~~ j i~L_.~L if7l-~"'---l TRt-'lMNc. F'LAPS ,L--A-----,~: j TRt-'lt>l1NC! flaps O' :.::..:::0:"'""1=; ~0-- NO D\lE-RECOVERY FLAPS --x- -x-- FG. 9. WTH D\lE-RECOVER)' FLAPS FLAP<; 0' l1 w : 0' Effect f dive-recvery flaps. 'q.< 8 lift 1'2 COEFFCENTS. w 0 0:, ,.--...,,--, , e Mc "4 1 0 CL s ---~.--_ ~""""b;:-., _+---_ =...,.=---;::7-' j F~. 7. PTCHJNCi MO"'!E NTS. FLAPS " O , , r , Cr+c '4 \'0 - O s/-----_ /----'l''''''''''r----'''-..j-!::------''1'-==-'''--1-10!------l----.l l-- f j NO "ROUND - -x x- - WTH "ROUND -.sl.---.l _...l.- --"- --"- --"-...l F~. 8. PTCHNCt M0tv1E.NTS. SMALL-CHORD F'l.APS 60:'r)~-O FGS and 8. Effect f trimming flaps. SLATS O?EN (74/0 SPAN) FG. 10. Effect f grund.

35 0 \5 0'\ '05-0 \0 +", -, "'+ 8, -, ~\~~ Tp FLAP ONLy 8, ~w = _10 0 <, ~ / <, -, '\" -, \" <, -, -, ~~b~ f!:, 'G(''/' -, 0, " '6- 'l;. "~! "" s-:... " " f C L Tp &- BOTTOM F~AP5 / -. ~, ~=-;O/~ ~~1_200 ~-; d LARc,E-CHORD FLAPS} FLAP 5P~ SMAL.L-CHORD FLAPS EL[~ON SPAN e. &1 --b--' \'0 t-. z + O , :rr------, O \2 t----c ~-- ::.,._L+_----t---~ BOTH SURFACES O 10 DOUBLE SPLT FL.APS / ( LAR C,[ C K OR D) / \1 j/ UPPER SURF'ACE ONL.y / / / + SPAN SLATS - O S ""\ FG. 11. Pitching mments with duble split flaps '=i =f='==i-"'---..,l---,4--f-f- 5 0.% 5 PAN NOS E F'LAPS O B \ t-----,<===l=-~=--::>.----+_----t---~ BASC CASE WTH NO DEVCE'.S FLAPS 60 0 (SMALL-CHORO FLAPS N REAR POS',,) 06 t ~----_+t i''-! ')+ - -x-- NO SLOTS ORC,NAL SLOTS ( C,AP :;'}- 0 0 c:) >- tvjodfed SLOTS (C,AP ~ 0 02 c) Z FLAPS 0 1'( ~ _10 0 DuCT E:.NTRE:5 OPE.N FG. 13. '" \ 0 Prfile-drag cefficients with and withut anti-tip-stalling devices. FG. 12. Pitching mments with letter-bx slts. }W = 0 deg.

36 ~ ~ WTH FN FLAPS " A ~- -x_ r<, WTH!'N FLAPS 60' ",_1- --'" c,r O B 1'0 Cl- 2 - WAPS NO Sl.ATS ---x-- -x-- WTH 37% \ SPAN SLATS. 1"1/4 14. n u ~S. C L t---.:.--7'f------,r----,~----j O B CN en - 0 ' -0''2 ~ ~~./, x-.:v-~-_ -' _x -x- - - F'L..APS 60 e -S 'l.r - 0' NO SLATS -x- - -x- - WTH 37 ~. SPAN SLATS 1"1"'.15. tv V5. C L 0 -c-: ' ' : J-G~ A- '" =8 45' 01. '" 9.85' d." 11'35 - O'.. O 2 / O NO FN FLAPS J;'c.r-,.../ -,,/, /---"'-'. ~ x-_ x WT~ FN FLAPS O WTH FN F"LAPS 60 \ NO SL.ATS - -x- - -x-- WTH 37 ~ SPAN SLATS : FC>.16 Yu vs, CL '-- ---'_'- ' FG. 17. Yawing-mment curves. N slats. FGS. 14, 15 and 16. Lateral derivatives.

37 0> 4 S; ::: 1036 C" ; 103C" "'"=1,3'0 ::;,., x 0> 00 0 X :.., cc <;; " ;J: 7 S - 5 " h? c...,:. e WTH 74~ SPAN ~LATS l"j. 0 ", (PORT ELEVON) -30, , 2-4 -S $ '----''''-_-'-- -'- --J._ 6 ---'-_---:.=-_.L..-...J F1q.Q YAWNGr MOMENT5 FLAPS O, r------, r ,------,----., 03A CG -5-7 S --8 B- e(.. 65~ x- l e" " --a---s-- = S, OS" '" -V 'V L :: 16 6" :: ie- S" '" -----t j,~.,:;:A l ~~i4_ "f':..., (PORT E:L,VON) 10, = ' 35 } NO ~ &-- '" = 8 45 SLATS l( 0( = 13 (,0 ;; x----x- - {= 1.3.",0 WTH 74% SPANSLATS..; > z llt ---' L -12 Sl.-...L- ----L ---l FG. 18. Yawing-mment curves with 37 per cent span slats. '----.,l<?"_.l-.l-_~-40l- '..l FG. 20. ROLLG MOME NTS. FLAP5 FGS. 19 and 20. Elevn pwer (rjw = elevn angle measured alng wind).