An experimental investigation into the aerodynamic characteristics of a wing, with and without endplates, in ground effect

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CoA R E P O R T A E R O No. 201

7 '^l'

_{b. 1968}

IISCHE HOGESCHOOL ÖELFT

VUEGTUfGBOUW KUNDE Dio! ' A T i i r r i ' '

T H E C O L L E G E OF A E R O N A U T I C S

C R A N F I E L D

AN E X P E R I M E N T A L I N V E S T I G A T I O N I N T O T H E

A E R O D Y N A M I C C H A R A C T E R I S T I C S O F A WING,

W I T H AND W I T H O U T E N D P L A T E S , IN GROUND E F F E C T

by

P . E. K u m a r

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CoA R e p o r t A e r o No. 201 M a r c h , 1968.

THE COLLEGE OF AERONAUTICS

CRANFIELD

An E x p e r i m e n t a l Investigation into the A e r o d y n a m i c C h a r a c t e r i s t i c s of a Wing, With and Without E n d p l a t e s ,

in Ground Effect.

by

p . E. K u m a r , B. Sc. (Eng). A. C. G. I.

SUMMARY

T h e s e wind-tunnel t e s t s w e r e conducted on a wing of a s p e c t r a t i o 2 in o r d e r to obtain a feel for the a e r o d y n a m i c c h a r a c t e r i s t i c s in ground effect, p a r t i c u l a r l y in the l a t e r a l m o d e s w h e r e t h e r e i s a s i n g u l a r lack of knowledge.

The effect of endplate and wingtip-body t h i c k n e s s on the f o r c e s and m o m e n t s a c t i n g on the wing w a s i n v e s t i g a t e d . In view of the n o n l i n e a r v a r i a t i o n s of the a e r o d y n a m i c loads it was not p o s s i b l e to obtain a e r o d y n a m i c s t a b i l i t y d e r i v a t i v e s a s u s e d in s t a n d a r d a i r c r a f t s t a b i l i t y p r a c t i c e , but it i s thought that s t e p by s t e p c a l c u l a t i o n s , at v a r i o u s h e i g h t s above ground, will yield a b e t t e r u n d e r s t a n d i n g of the o v e r a l l dynamic stability. In all t e s t s the ground w a s r e p r e s e n t e d by an iniage wing s y s t e m .

T h i s work was conducted u n d e r M i n i s t r y of Technology C o n t r a c t No. P D / 2 8 / 0 1 6 .

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SYMBOLS

b b a s i c wing span

b m e a n wing span of wing with endplates o r t i p - b o d i e s c wing c h o r d

t / c wing t h i c k n e s s / c h o r d r a t i o

h height of wing u n d e r s u r f a c e q u a r t e r - c h o r d above ground

ho " " " " ' " at lowest tip (banked c a s e s only)

g gap at b a s e of endplates

L, C L o v e r a l l lift and lift coefficient of wing D, C Q o v e r a l l d r a g and d r a g coefficient of wing

M, Cyi o v e r a l l pitching m o m e n t and pitching m o m e n t coefficient of wing S o v e r a l l wing a r e a

N, C ^ o v e r a l l yawing m o m e n t and yawing m o m e n t coefficient of wing Y, C o v e r a l l s i d e f o r c e and s i d e f o r c e coefficient of wing

f_i, C o v e r a l l r o l l i n g m o m e n t and r o l l i n g m o m e n t coefficient of wing

X c e n t r e of p r e s s u r e position of wing, a s fraction of c h o r d ^ c / 4 q u a r t e r c h o r d position of wing (= 0. 25) a s f r a c t i o n of c h o r d

a wing incidence m e a s u r e d along u n d e r s u r f a c e a wing incidence m e a s u r e d along chordline

/S s i d e s l i p angle ^ bank angle

In t a b l e s : Y wingtips (or half-bodies) o r endplates a r e of C l a r k Y section i Y " " " " " a r e of "half C l a r k Y "

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1

-1. o Introduction

C u r r e n t i n t e r e s t in the concept of using a ground effect wing (GEW) a s a future m e a n s of t r a n s p o r t , h a s highlighted the lack of existing knowledge on the s t a b i l i t y c h a r a c t e r i s t i c s of such a craft. As mentioned in ref. 1, such a craft might conceivably take the form of two wings with endplates in a tandem configuration, and it was with t h i s form in mind that the p r e s e n t s e r i e s of wind-tunnel e x p e r i m e n t s w e r e conducted to throw light on s o m e of the stability p r o b l e m s i n h e r e n t in a GEW. The p r e s e n c e of the ground was s i m u l a t e d by using an i m a g e wing s y s t e m .

2. 0 Model Details

The model and image wings w e r e of C l a r k Y s e c t i o n , being the s a m e a s t h o s e used by Ashill (ref, 2), and t h e i r significant d i m e n s i o n s w e r e :

-Span (excluding endplates o r t i p bodies) b = 4 ft Chord (constant along span) c = 2 ft T h i c k n e s s / c h o r d r a t i o t / c = 11.7%

The endplates used by Ashill w e r e of t / c = 6% and of a section obtained by halving the t h i c k n e s s of the C l a r k Y section at each station along its chord. We s h a l l , for the s a k e of s i m p l i c i t y , r e f e r to these endplates a s being "half C l a r k Y " . In addition to t h e s e , a f u r t h e r s e t of endplates of full C l a r k Y section w e r e m a d e with t / c = 11.7%.

The wingtip f a i r i n g s used by Ashill w e r e half-bodies of revolution of t / c = 6% and, a s for the endplate c a s e , t h e s e shall be r e f e r r e d to a s being "half C l a r k Y" wingtip-bodJes. A further set of wingtip-bodies of t / c = 11. 7% w e r e m a d e to a full C l a r k Y section.

The model and its i m a g e wing w e r e naounted in the A e r o d y n a m i c s D e p a r t m e n t ' s 8' X 6' subsonic wind-tunnel using the s t r u t s noted in ref. 2, for the longitudinal q u a s i - s t e a d y c a s e s . F o r the l a t e r a l q u a s i - s t e a d y c a s e s of r o l l and yaw a s p e c i a l s e t of s t r u t s w e r e m a d e . T h e s e enabled the wings to be yawed, maintaining the s t r u t fairings at z e r o incidence to the airflow t h e r e b y reducing the effect of l a r g e r w a k e s on the wing u p p e r s u r f a c e s . In addition the image wing could be banked and shifted h o r i z o n t a l l y to m a i n t a i n a t r u e ground plane. The banking was achieved by having v e r y tight hinges at the b a s e s of the i m a g e s t r u t s w h e r e they located onto the image wing, the s t r u t s being able to slide h o r i z o n t a l l y between two clamping p l a t e s .

The closed configurations, at z e r o yaw and bank, can be s e e n in F i g s . 1 and 2 for half C l a r k Y and C l a r k Y endplates r e s p e c t i v e l y . Fig. 3 shows the m o d e l and i m a g e wings in a banked setup with C l a r k Y e n d p l a t e s .

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2

-3.0 Tests

(a) Longitudinal

All tests were conducted at a tunnel working section speed of 100 ft/sec at a dynamic p r e s s u r e of 11. 89 lb/in". The closed configui-.ition cases, as in Figs. 1 and 2, were tested at heights hp above ground, of 2. 025", 4. 025" and 6. 025" through an incidence range of a = 0°, 3" and 6" for each case. The relevant geometric set-up was as sketched below

GROUND PLANE

Each incidence case was run with (i) Clark Y endplates (ii) half Clark Y endplates (iii) Clark Y wingtip fairings (iv) half Clark Y wingtip fairing

with the gap 'g' = 0. 020" in all cases with endplates.

Further, at the 6. 025" height, tests were conducted using parallel end-plates of 2" and 4" depth through the sanie incidence range as before. This setup is sketched below

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(b) Lateral - Sideslip

The sideslip cases were done at the same three heights as the longit-udinal cases, for 5 = 0 , 3° and 6°, Only the closed configurations with endplates were used through sideslip angles of 0°, 6° and 9°, at each incid-ence setting. The strut fairings were always at zero incidincid-ence to the free stream. In addition to the above incidence range it was also possible to get 5 = -2° for the Clark Y endplate cases only.

View on upper Surface of model wing showing model at sideslip ^ with strut fairings in line with the free stream.

(c) Lateral - Roll

The image wing was banked, as shown in Fig. 3, and shifted horizon-tally to maintain a true ground plane. Cases at the three previous incidences i. e. 5 = 0°, 3° and 6° were done at three nominal heights of 2. 025", 4. 025" and 6. 025" measured at the lowest tip. It was possible to do cases at 5 = - 2 ° , for the Clark Y endplate and wingtip-body configurations only. Baulk angles of ^ = +2°, +4° and +6° were tested at each height and incidence setting.

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4 . 0 A n a l y s i s

The signconvention u s e d can be s e e n in Fig. 4. All f o r c e s and m o m e n t s w e r e n o n d i m e n s i o n a l i s e d by taking the actual plan a r e a of the a p p r o -p r i a t e configuration, which in the c a s e of C l a r k Y end-plates and wingti-p bodies was 8.64 ft^ whilst that of the half C l a r k Y s e t - u p was 8.32 ft . In addition the effective span was taken for n o n - d i m e n s i o n a l i s i n g the rolling and yawing m o m e n t s i. e. for C l a r k Y configurations b = 4. 32 ft

and " half C l a r k Y " b = 4, 16 ft

In the bank c a s e s the actual height at the lowest tip m e a s u r e d at q u a r t e r c h o r d on the lower s u r f a c e of the wing, differs from the nominal heights p r e v i o u s l y quoted, due t o ^l> and the endplate configuration. The following table gives the c o r r e c t v a l u e s of h :

-(/> n o m i n a l 2 4 6 h (inches C l a r k Y 2. 121 2. 216 2. 328 4. 118 4. 205 4. 317 6. 118 6. 205 6. 297 ) half Clark Y 1 2.075 2. 135 2. 20 4.078 4. 125 4. 187 6.078 6. 125 6. 167 4. 1 Wind-tunnel c o r r e c t i o n s (a) Blockage

BJockage c o r r e c t i o n s to the a i r s p e e d at the model w e r e e s t i m a t e d a c c o r d i n g to the method given in ref. 3. The solid blockage due to the m o d e l and i m a g e wings was found to be Au = . 004 U^, and that due to the i m a g e s t r u t fairings 0. 0015 U w h e r e Au i s the c o r r e c t i o n to the velocity at the m o d e l in t e r m s of the free s t r e a m velocity U^p. The blockage due to the w a k e s of the m o d e l and i m a g e wings was 0. 001 U^p. Hence the o v e r a l l b l o c k -age c o r r e c t i o n to the a i r s p e e d at the m o d e l i s . 0065 U ^ . which i s s m a l l and h a s , t h e r e f o r e , been neglected.

(b) The c o r r e c t i o n s to the lift and d r a g of the m o d e l wing due to the i m a g e s y s t e m , of the t r a i l i n g v o r t i c e s , in the tunnel w a l l s h a s been d e t e r m i n e d in ref. 2 using the method given in ref. 4. Once again t h e s e c o r r e c t i o n s w e r e found to be v e r y s m a l l and have consequently been neglected.

(c) Strut i n t e r f e r e n c e

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5

-f e r e n c e have been obtained in re-f. 2 by m e a n s o-f a dummy s t r u t -fairing located at wing c e n t r e - s p a n . The changes in the a e r o d y n a m i c f o r c e s w e r e c o r r e l a t e d against the l o c a l c e n t r e - s p a n lift coefficient a s d e t e r m i n e d by p r e s s u r e plotting. C o r r e c t i o n s to o v e r a l l wing C^ can be found in ref. 2, for the longitudinal c a s e s , and have been applied to the p r e s e n t c a s e s of s i d e s l i p and bank.

The fairings at the junctions of the wing and the s t r u t s w e r e m a d e of s h e e t m e t a l with t h e i r l o w e r edges contoured to m a t c h the wing s u r f a c e . A gap of 0 . 0 1 5 " was m a i n t a i n e d , in all t e s t s , between the wing s u r f a c e and t h e s e f a i r i n g s , and the effect of t h i s gap on the o v e r a l l f o r c e s acting on the wing i s given in ref. 2. However, b e c a u s e of the s t r u t s being located in a r e a s of high suction o v e r the wing, a i r w a s sucked down the length of the s t r u t fairing and blown out through the gaps into the s t r u t w a k e s . T h i s r e s u l t e d in w i d e r w a k e s . F i g s . 5(a) and (b) show the d e c r e a s e in the s t r u t wake width by s e a l i n g off the s t r u t fairing at its top end i. e. at the b a l a n c e end. It was not p o s s i b l e to u s e such a s e a l during m e a s u r e m e n t t e s t s on account of i t s i n t e r f e r e n c e with the b a l a n c e . Since the s t r u t i n t e r f e r e n c e c o r r e c t i o n s given in ref. 2 had been obtained e x p e r i m e n t a l l y and a r e e x t r a p -olated to z e r o gaps between the s t r u t f a i r i n g s and the wings, the effect of the "blown" a i r h a s , in e s s e n c e , been c a t e r e d for a l r e a d y .

(d) Strut flexibility c o r r e c t i o n s

In analysing the wind-tunnel r e s u l t s for the f o r c e s and m o m e n t s acting on the wing, it was a s s u m e d that the s t r u t s being u s e d w e r e rigid. This i s t r u e for the longitudinal c a s e s , but for the l a t e r a l c a s e s w h e r e the s p e c i a l s t r u t s w e r e being used, a c o r r e c t i o n h a s to be m a d e to the r e s u l t s to allow for theii' flexibility.

If we denote the r e c i p r o c a l of the stiffness of the s t r u t s by m = d x / d D , m = dy/dY and m = dx^JdM

X ' y ^' xjyi M'

then, for the new s t r u t s we have from c a l i b r a t i o n c u r v e s , m = . 000984 i n s / l b d r a g .

m = . 00166 i n s / l b s i d e f o r c e .

m = . 0000395 i n s / l b in pitching m o m e n t . "'M

Hence the deflection of the s t r u t in the downwind d i r e c t i o n i s E6x = (. 000984D + . 0000394M) ins

.'. reduction in model wing incidence i s

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qS(. 000984 C^^ + . 0000395 C^^ c)

= : , where 'q' is the dynamic

s pressure

Hence the change in lift coefficient is

AC = a 6a where a is the lift curve slope.

i-j 1 1

However, on account of the non-linear lift curves it was not possible to use one value of a^ for each case, and the complex structure of the new struts made it difficult to define 1 exactly. Fig. 6 shows the lift curves,

s

for a particular closed configuration, using rigid struts, flexible struts and that estimated for rigid struts using the above method taking the linear value of a . It can be seen that the agreement between the measured lift curve and that estimated using flexible strut data is not very good. It was decided, therefore, to correct the flexible strut data by means of the experimentally obtained differences between the rigid and flexible struts, for the longitudinal cases, assuming that these apply to the sideslip and bank cases as well.

5.0 Results

5, 1. 0 Longitudinal Results

Table 1 sets out lift, drag and pitching moments obtained for the wing,

with endplates or tip-bodies, at three different heights above ground. The

cases with parallel endplates in and out of ground effect are also included and the results are plotted in Figs. 7(a) to 21 inclusive.

5. 1. 1 Discussion of Longitudinal Results

Figs. 7(a), (b) and (c) show the lift curves for the various cases con-sidered. It can be seen that the effect of endplates is to increase the lift over that achieved by the wing with tip fairings, whilst the proximity of the ground (in this case the image wing system) results in a non-linear lift curve. Comparison of experimental results with theory, for the half Clark Y endplate configuration, can be seen in ref. 2. It is not immediately

obvious as to why the half Clark Y endplates result in higher lift coefficients at incidences above a = 2° but it is thought to be due to powerful trailing vortices arising from the gap at the base of the endplates. Unfortunately, two parameters are involved, in going from the half Clark Y endplates to the full Clark Y ones, these being thickness and camber and it is difficult at present to assess their separate effects on the lift curves. It is hoped to be able to investigate the effect of these endplate parameters in the near future.

Another Interesting feature is to be seen in Fig. 7(a) where the lift of

the wing with half Clark Y wingtip bodies increases, above a = 6 , and

becomes greater than that of the wing with Clark Y wingtip bodies. This is thought to be due to the strong suctions induced on the upper surface of the

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7

-wing, in the tip regions, by the trailing vortices resulting from flow separ-ation over the half Clark Y wingtip bodies. Fig. 7(d), although for a different case, shows the trailing vortices, at a position 5" aft of the wing trailing edges, and the position of their cores above (or below) the ground plane. The Clark Y wingtip bodies prevent flow separation occurring until a much larger incidence than that reached in Fig. 7(a), separation being due to strong spanwise cross flows on the under surface of the wings.

Figs. 8(a) and (b) indicate the increase in lift obtained on approaching the ground at constant incidence. Points from ref. 2, for the case of flat endplates, have been included in Fig. 8(a) for a = 2° and show the slight reduction in lift incurred by their use compared to those of the half Clark Y endplates. The results from ref. 5, shown in Fig. 8(b), for the case of a Clark Y wing of aspect ratio 2, but no wingtip bodies, indicate higher lifts than those achieved with the use of wingtip bodies. This is again due to the strong trailing vortices, resulting from flow separation over the wingtips, inducing suctions on the wing upper surfaces in the tip regions (as noted previously for Fig. 7(a).)

Figs. 9(a), (b) and (c) show the drag curves. The reduction in drag due to the endplates is evident in all cases.

Figs. 10(a)—> 11(c) give the variation of drag with height, at constant

a, and with lift coefficient, it can be seen that for a small departure from

the ground at constant a the drag does not vary very much.

Figs. 12(a), (b) and (c) show the variation of wing pitching moment, about it quarter chord, with lift whilst Figs. 13(a)—» (d) show its variation with height above ground at constant a. At large values of incidence (or lift) the pitching moment gets progressively nose up on departure from the ground. Figs. 14(a)—* (d) give the centre of pressure positions obtained from Figs. 13(a)—» (d) using linear theory i . e . _ -C

C /4 = (x„ - x , ). mc/'* c c c / 4 ' It is not possible to determine the aerodynamic centre positions on account of their non-linear relationship with height above ground.

The variation of lift/drag ratios with lift coefficients are plotted in Figs. 15(a)-—> (d). Maximum value of L/D measured was 95 occurring at the lowest height of the Clark Y endplate configuration for a = 8°. It is interest-ing to note that there is a maximum value of L/D occurrinterest-ing at the lift coef-ficient just prior to flow separation resulting in larger drag values. Fig. 15(d) shows a flattening off in the curve for hp = . 0405, and half Clark Y

wing-tip bodies, and is due to the increase in C, resulting from flow separation over the wingtips (see Fig. 7(a)). A comparison of the effects of basic wing thickness has also been plotted in Fig. 15(d) from results of refs. 5 and 6, In general the effect of wing thickness is to reduce the maximum value of L/D as compared with a thinner wing.

Results for the cases of wings with parallel endplates are plotted in Figs. 16—*21. The lift drag curves, in and out of ground effect, are shown in Figs. 16 and 17, the larger drag values occurring for the 2" parallel

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end 8 end

-plate cases. _The lift/drag ratios once again exhibit maximum values mostly at the lower C ^ ' s . At the higher C 's and hence incidences, separation occurs along the bottom edges of the endplates resulting in stronger trailing vorticity.

* These longitudinal results a r e found to be in good agreement with those previously obtained by Ashill in ref. 2.

5. 2. 0 Sideslip Results

Table 2 shows the results obtained for the forces and moments acting on the yawed wings in ground effect, for three heights above the ground. The results are plotted in Figs. 22(a)—> 29(f).

5. 2. 1 Discussion

Figs. 22(a)—> 23(b) show the lift variations obtained due to changes in sideslip at constant heights and incidences, the effect of sideslip being to reduce the lift slightly. The lift slopes are still non-linear, as in the long-itudinal and banked cases, and the larger lifts occur for the cases with half Clark Y endplates.

The drag increases with sideslip, incidence and height above ground as can be seen in Figs. 24(a) —> 24(f). However, the (lift/drag) ratios decrease with sideslip in all cases, except that at heights above 2. 025" the maximum value of L/D occurs at an incidence of about 5 . This can be seen in Figs. 25(a)--^ 25(f).

Sideslip has little effect on the wing pitching moments at large incidences and small heights above ground. At incidences up to about 5° the pitching moment decreases with sideslip (i. e. gets more nose down). At the 6. 025" height, however, and for all incidences, the pitching moment decreases with increase in sideslip as can be seen from Figs. 26(a)—^ 26(f).

The rolling moments increase with sideslip, at a given incidence,

except that for the larger incidences (over 7°) they decrease and are negative. The maximum rolling moment, at any fixed sideslip, occurs at the lowest incidence and height above ground as can be seen from Figs. 27(a) —i 27(f). Rolling moments obtained from ref. 5 for a wing with flat endplates are shown in Fig. 27(f) and the disagreement is due primarily to there being a gap

between the bases of the flat endplates.

Figs. 28(a)—> 28(f) show the yawing moments which are positive and increase with sideslip and incidence. Some doubts as to the accuracy of the results for the case a = 8 in Fig. 28(d) arose and consequently these are shown by a dotted line until they can be repeated sometime in the future. Once again the result from ref. 5 has been shown in Fig. 28(f) and as expected, the agreement with the present results is not good.

The variation of sideforce with sideslip and incidence is shown in Figs. 29(a)—> 29(f). The sideforce decreases with sideslip i . e . gets more negative in the sign convention being used, and the maximum values (negative) occur for the lowest incidence tested. Results from ref, 5 have been included

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in Fig. 29(f) and agreement with the present results is good up to about 5° of sideslip.

In view of the non-linearities in the C^, C^^ and C ~- ^ curves it is not possible to obtain the sideslip derivatives as in normal aircraft stability practice. However, it is possible to determine the instantaneous values of these derivatives to use in step by step calculations at different heights, in order to get some feel for the dynamic behaviour of the wing.

5. 3. 0 Roll Results

Table 3 sets out the results for the forces and moments acting on the banked wing in ground effect, for three nominal heights above ground, m e a s -ured at the lowest tips. Figs. 30(a)—»35(1) show the results plotted.

5. 3. 1 Discussion

The lift, drag and pitching moment characteristics of the banked config-urations tested are to be seen in Figs. 30(a) to 32(f). However, the m.ain interest in banking the wing was to obtain the effect of the ground on the lateral quasi-static "derivatives". The word "derivatives" is here used loosely to describe the effect of bank on the sideforce, rolling and yawing moments. In view of the non-linear characteristics of these parameters, however, the usual stability derivative concept cannot be used since it is based on linearisation of the problem. Figs. 33(a) to 35(1) cover the variat-ions of C,, C and C with the bank angle <j) and the height above ground h , defined at the lowest tip. Using the sign convention of Fig. 4, and with reference to section 2. 2 of ref. 1, one expects a negative rolling moment for a positive bank angle. This is in fact the case in Figs. 33(a)—•33(1). the magnitude of the rolling moment increasing with incidence at constant bank and height, and decreasing with increase in height at constant incidence and bank angle. The rolling moments for the configurations with wingtip bodies are very much smaller than the corresponding cases with endplates. and for the a = 0° cases shown the rolling moment changes sign. This is due to the "venture effect" occurring between the lowest wingtip and the ground resulting in suctions on the lower wing surface. The strangely non-linear character-istics of the large incidence cases at larger heights are probably due to

separations occurring over the wingtips. as mentioned earlier for cases in section 5. 1, 1, giving rise to lower pressures on the wing upper surface at the lower wingtip than on the upper wingtip.

Figs. 34(a)—> 34(1) show the yawing moments due to bank, in ground effect, and are in the negative sense (see Fig. 4) as anticipated in section 2. 2 of ref. 1. As in the case of the rolling moments, non-linearities appear at the large incidences and heights and may again be attributed to the complex flow separations occurring at the bases of the endplates and over the wingtip bodies. The maximum yawing moments are of the same order for the end-plate and wingtip-body configurations.

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-Figs. 35(a)—> 35(1) show the variations of the sideforce coefficient due to bank. The sense of the sideforce is once again as anticipated in ref. 1. The sideforce. in the cases with endplates, increases with increase in height above ground and with incidence. This is not altogether unexpected since the major contribution towards the total wing sideforce comes from the loading on the endplates i. o. the larger the endplate the larger the sideforce. This, of course, does not hold true for the wingtip-body configurations where the side-force decreases with increase in height above ground.

6.0 Conclusions

These wind-tunnel tests were conducted in order to fill in a large gap existing in the knowledge of the lateral characteristics of a wing flying near the ground and so far as the author is aware, are the first lateral-mode tests in ground effect to be conducted in this country. The effect of endplates and wingtip bodies of two different thicknesses have been determined in order to provide data towards designing a stable G. E. W. The main problem in this design is the longitudinal dynamic pitching instability that occurs on departure from the ground and was mentioned previously in ref. 1. The present experimental results will enable a step by step evaluation of the quasi-steady stability to be made at different heights above the ground in the hope of clarifying the overall response and motion of a G. E. W. to disturb-ances near the ground. Dynamic results from the College of Aeronautics Whirling Arm will provide further response data in the future.

At present no adequate theory exists to cater for the lateral sideslip and bank cases of a wing in ground effect but it is hoped that a suitable one may be developed in the near future. A theory for the longitudinal steady cases for minimum induced drag may be found in ref. 2. The present longitudinal test results are in general agreem,ent with those previously obtained by Ashill.

Acknowledgem ents

The author is extremely grateful to the Ministry of Technology for their support of this work, and to M e s s r s . Lilley, Sibley and Tucker of the Aerodynamics Department for their invaluable help in conducting the experi-ments.

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11

-R e f e r e n c e s

1. Stability of Ground Effect Wings - P . E. K u m a r , CoA R e p o r t A e r o 196 May 1967.

2. Unpublished PhD T h e s i s 1968 - P . R. Ashill.

3. Wind-Tunnel T e c h n i q u e s - P a n k h u r s t & H o l d e r . 1952.

4. Wind-Tunnel C o r r e c t i o n s on Ground Effect - W. S. Brown, R & M 1865, 1938.

5. W i n d - T u n n e l Investigation of Single and Tandem Low A s p e c t - R a t i o Wings in Ground Effect - Lockheed R e p o r t 16906, M a r c h 1964. 6. A e r o d y n a m i c C h a r a c t e r i s t i c s of Low A s p e c t Ratio Wings in C l o s e

(15)

TABLE 1 LONGITUDINAL CASES a = a = a = a = a = a = a = a = a = a = a =

2°.

5°,

8°.

2°.

5°.

8°,

- _ 5 ° . 8 ° . 0 ° , 0 ° : C A S E | Y W i n g t i p s Y ^ Y E n d p l a t e s Y \Y W i n g t i p s Y | Y E n d p l a t e s Y \Y W i n g t i p s Y i Y E n d p l a t e s Y | Y W i n g t i p s Y j Y E n d p l a t e s Y | Y W i n g t i p s Y \Y E n d p l a t e s Y | Y W i n g t i p s Y | Y E n d p l a t e s Y | Y W i n g t i p s Y | Y E n d p l a t e s Y | Y W i n g t i p s Y \Y E n d p l a t e s Y \Y W i n g t i p s Y | Y E n d p l a t e s Y ^ Y W i n g t i p s Y Y E n d p l a t e s \Y W i n g t i p s Y Y E n d p l a t e s h P 2. 0 2 5 ' f 4 . 0 2 5 \ 6. 0 ' 1 25 r 2 . 0 2 5 6 . 0 2 5 1

f

^ L . 295 . 29 . 557 . 527 . 6 3 4 . 639 1. 043 1. 049 1. 13 1. 0 0 4 1. 43 1. 4 0 7 . 286 . 289 . 525 . 529 . 516 . 522 . 915 . 8 7 . 7 2 9 . 738 1. 243 1. 144 . 275 . 276 . 522 . 51 . 4 7 . 476 . 83 . 8 0 1 . 657 . 6 7 1. 10 1. 03 . 0 9 3 7 . 0 8 1 3 . 145 . 3013 ^ D . 0 1 6 . 0 1 5 7 . 0 1 1 1 . 0 1 1 . 0 3 3 8 , 0 3 4 7 . 0 1 3 0 5 . 0 1 1 6 0 . 0 5 7 1 . 0 5 5 1 . 0 1 6 9 . 0 1 4 9 . 0 1 7 6 4 . 0 1 7 4 . 0 1 1 7 . 0 1 1 1 . 0359 . 0 3 4 8 . 0 1 3 6 . 0 1 3 0 . 0 5 9 3 . 0 5 6 8 . 0 2 2 5 . 0 2 0 1 . 0 1 9 1 . 0192 . 0 1 1 6 3 . 0 1 2 3 5 . 0357 . 0 3 5 5 . 0 1 6 . 0 1 5 1 . 0 5 8 2 . 0 5 8 1 . 0 2 3 5 . 0 1 9 8 . 0 0 9 5 . 0096 . 0 1 0 2 . 0 1 2 1 4 L / D 1 8 . 4 5 1 8 . 4 5 5 0 . 20 4 8 . 0 0 1 8 . 7 5 1 8 . 4 1 8 0 , 0 0 9 0 . 50 19. 8 18. 23 8 4 . 6 9 4 . 5 16. 20 1 6 . 6 6 4 4 . 90 4 7 . 60 14. 36 15. 0 0 6 7 . 30 6 7 . 0 0 12. 30 1 3 . 23 5 5 . 3 0 57. 00 14. 44 14. 40 4 4 . 90 4 1 . 30 1 3 . 16 13. 41 52. 0 5 3 . 10 1 1 . 30 1 1 . 52 4 6 . 8 0 5 2 . 0 0 9. 87 8. 50 1 4 . 2 1 2 4 . 80 • ^ M c / 4 . 0 4 1 . 0 3 7 9 . 0 6 5 7 . 0 6 2 5 . 0 4 6 3 . 0 4 4 9 . 1123 . 108 . 096 . 0 7 8 . 2 0 1 5 . 1935 . 0 4 3 7 . 0 4 1 4 . 0 6 4 1 . 0 6 1 9 . 0 4 2 2 . 0 3 8 8 . 0 7 6 5 . 0752 . 0 4 5 8 . 0 4 0 4 . 0 9 1 . 0 9 8 5 . 0 4 5 8 . 0426 . 0 594 . 0G25 . 0 3 9 5 -. 0 5 9 9 . 0 6 6 3 . 0 3 7 1 . 0 3 . 0589 . 0742 .0481 1 . 0 4 8 7 .0511 1 . 0 6 2 8 ^ c p / ^ . 3 8 9 . 3 8 0 6 . 3 6 8 . 3 6 8 6 . 3 3 0 8 . 3 2 0 3 . 3 5 7 5 . 353 . 3 3 5 . 3 2 7 7 . 3 9 1 . 3876 . 4 0 3 . 3 9 3 2 . 372 . 3 6 7 . 332 . 3 2 4 3 . 3336 . 3 3 6 5 . 313 . 3 0 4 8 . 3 2 3 2 . 336 1 . 4 1 6 5 . 4 0 4 5 . 3 6 3 6 j . 3 7 2 5 ! . 33 i'l 1

1

. 3 2 2 2 1 . 3 3 2 8 . 3 0 6 4 . 2 9 4 8 . 3 0 3 5 . 322 1 .3013 1 . 310 . 2852 . 2 7 0 9

(16)

TABLE 1 LONGITUDINAL CASES (contd. ) CASE Q = 2 ° , 2"//Y E n d p l a t e s 4"//Y " 2 " / / i Y " 4 " / / i Y " 0 = 5 ° . 2"//Y 4"//Y " 2 " / / i Y " 4 " / / i Y " a = 8 ° . 2"//Y 4"//Y " 2 " / / i Y " 4 " / / i Y " a = 2 ° . 2"//Y 4"//Y " 2 " / / i Y " 4 " / / i Y " a = 5 ° , 2"//Y 4"//Y " 2 " / / i Y " 4 " / / i Y " a = 8 ° , 2"//Y 4"//Y " 2 " / / i Y " 4 " / / i Y h P 6. 025 1 1 O G E 1 ^ L . 314 . 304 . 304 . 343 . 542 . 6 4 1 . 534 . 625 . 768 . 92 . 755 . 907 . 268 . 281 . 266 . 2785 . 4 1 6 . 433 .416 . 3 9 . 5 7 2 . 5 9 3 . 593 . 592 ^"D . 0199 .0210 . 0198 . 206 . 0367 . 0359 .0359 . 0347 . 0593 . 0511 . 0581 .0520 . 0211 . 0223 . 0210 . 0218 . 0361 . 0375 . 0360 . 0375 . 0590 . 060 . 0593 . 060 L / D 15. 79 14. 50 15. 35 16.65 14. 79 17. 86 1 4 . 8 5 18. 00 12. 96 18. 00 13. 00 17.42 12. 70 12. 60 12.67 12. 80 11. 53 11. 55 11. 55 10. 40 9. 70 9. 89 10. 00 9. 88 '" r " ^ M c / 4 . 0426 . 0 4 6 2 . 0605 . 0 6 2 8 . 0 3 9 1 . 0474 . 0500 . 0496 . 0388 . 0582 . 0466 . 0486 . 0499 . 0528 . 0 5 2 2 . 0 5 4 4 . 0425 . 0 4 3 8 . 0458 . 0476 . 0393 . 0 3 9 5 . 0435 . 0442

^cp/c

1 .3855 1

. 402 . 449 . 4 3 4 . 3 2 2 . 3 2 4 . 328

. 329 1

. 301 . 3 1 3 3 . 3 1 1 8 . 3036 . 4 3 6 . 438 . 4 4 6 . 4 4 5 . 3 5 2 . 351 . 3 6 0 . 372 . 3 1 9 . 317 . 323 . 325

(17)

TABLE 2 SIDESLIP TESTS C A S E a = 0 ° . Y E P ' s P = 0 ° . 30 1 6 ° 9 ° ' a = 2 ° . Y E P ' s ^ = 0 ° 3 ° 6 ° 9 ° a= 2 ° . i Y E P ' s ^ = 0 ° 3 ° 6 ° 9 ° 0 = 5 ° . Y E P ' s ^ = 0 ° 3 ° 6 ° 9 ° a = 5 ° , i Y E P ' s ^ = 0 ° 30 6 ° 9 ° a = 8 ' . Y E P ' s ^ = 0 ° 3 ° 6 ° 90 a = 8 ° , i Y E P ' s ^ = 0° 30 6 ° 9 ° h P 2. 02 1 5 " ^ L . 1451 . 1489 . 1471 . 1 4 2 5 . 542 . 542 . 540 . 526 . 5 5 . 55 . 538 . 528 1. 0 4 3 1. 0 2 8 1. 022 1 . 0 0 4 1. 032 1. 036 1. 032 1. 0 2 3 1. 4 0 5 1 . 4 0 5 1 . 4 0 5 1. 4 0 5 i 1 . 4 4 2 1 . 4 3 2 1 1 . 4 3 2 f i 1 . 4 3 2 ^ D . 0 1 0 2 . 0 0 9 7 . 0 1 0 8 . 0 1 1 1 . 0 1 1 3 6 . 0 1 1 3 6 . 0 1 2 3 8 . 0 1 2 7 . C 1 1 0 6 . 0 1 1 4 3 . 0 1 2 0 . 0 1 3 1 . 0 1 3 1 . 0 1 3 2 . 0 1 4 3 . 0 1 5 6 . 0 1 3 0 5 . 0 1 2 9 5 . 0 1 4 2 . 016 . 0 1 5 5 . 0 1 6 2 . 0 1 7 4 . 0 1 8 6 . 0 1 7 2 . 0 1 7 3 . 0 1 7 6 . 0 1 9 ' ^ M c / 4 . 0 4 3 1 . 0 4 6 2 . 0 5 0 3 . 0 5 8 5 . 0 6 3 1 . 0 6 4 1 . 0 6 7 . 0 7 2 4 . 0659 . 0 6 6 7 . 069 . 0 7 5 . 108 . 1063 . 1105 . 1154 . 1106 . . 1 1 1 1 . 112 . 1137 . 194 . 194 . 194 . 194 . 202 . 206 . 2 0 2 3 . 202 C^XIO^ . 412 2 2 . 3 3 7 . 3 . 9 3 1 6. 58 1 3 . 7'3 2 2 . 4 0 - 2 . 3 7. 3 8 1 6 . 4 6 2 5 . 60 1. 0 1 . 8 6 6. 25 1 3 . 4 0 0 1 . 3 3 5. 17 8. 24 0 - 6 - 1 1 . 4 - 1 3 . 4 5 1. 08 - 4 . 9 0 - 9 . 8 0 - 9 . 80 C ^ 1 0 3 0 1 . 3 4 1. 0 8 5 2. 28 . 2 8 7 1. 234 2, 4 3 2 . 6 3 0 1. 36 2. 85 4. 14 0 2. 3 0 5 5. 39 8. 76 - . 127 2. 36 4. 52 7 . 3 5 - . 1 4 1 3 . 28 6. 8 8 9 . 7 6 0 4. 2 7 . 6 0 9 . 8 0 C X I O ^ y . 214 - 6 . 2 - 1 8 . 0 1 - 3 0 . 3 0 - 1 . 4 9 6 - 5 . 85 - 1 3 . 8 0 - 2 2 . 4 0 1. 335 - 8 . 39 - 1 6 . 2 8 - 2 3 . 90 - . 2 1 - 1 . 5 - 5 . 0 - 1 1 . 0 - . 503 - 5 . 24 - 9 . 7 7 - 1 5 . 98 0 - . 4 0 - 1 . 4 - 1 . 4 - . 5 9 5 - 1 . 1 3 - 1 . 7 4 5 - 5 . 0 7 L / D 14. 22 1 5 . 3 5 1 3 . 6 1 12. 8 1 4 7 . 8 4 7 . 8 4 3 . 6 4 1 . 4 4 9 . 70 4 8 . 10 4 4 . 90 4 0 . 3 7 9 . 8 0 7 7 . 9 0 7 1 . 5 0 6 4 . 30 79. 2 1 8 0 . 0 7 2 . 7 64.0 1 9 0 . 6 86. 7 1 8 0 . 7 7 5 . 5 8 4 . 0 8 2 . 9 8 1 . 4 7 5 . 5 0

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TABLE 2 SIDESLIP TESTS (contd. )

1 CASE

a = 2 ° . Y E P ' s ^ = 0 ° 30 6 0

1 90

0 = 2 ° , | Y E P ' s ^ = 0 ° 3 ° 6 °

1 9°

0 = 5 ° . Y E P ' s ^ = 0 ° 3 ° 6 ° 1 90 1 0 = 5 ° . i Y E P ' s ^ = 0 ° 3 ° 6 °

1 9°

0 = 8 ° , Y E P ' s ^ = 0 ° 30 6 ° 90 a = 8 ° . i Y E P ' s )3=0° 3 ° 6 ° 90 0 = 0 ° , Y E P ' s /3 = 0 ° 30 60 9 ° h P 4 . 0 2 5 " \ f 6 . 0 2 5 " ^ L . 5 3 5 . 529 . 525 . 526 . 5 2 1 . 513 . 5 1 1 . 516 . 874 . 867 . 870 . 8 5 5 . 9 1 . 873 . 8 6 1 . 854 1. 140 1. 140 1. 140 1. 140 1. 24 1. 256 1. 2 6 2 1. 255 . 3 0 1 3 . 3059 . 2966 . 2846

s

. 0 1 1 0 5 . 0 1 1 1 6 . 0 1 2 3 5 . 0 1 3 6 4 . 0 1 1 9 7 . 0 1 3 1 . 0139 . 0 1 5 4 . 0 1 3 . 0 1 2 9 2 . 0 1 3 8 . 0 1 5 0 6 . 0 1 3 6 . 0 1 3 5 5 . 0 1 4 0 5 . 0 1 6 7 . 0 2 0 1 . 0206 . 0 2 1 9 . 0 2 2 7 . 0 2 2 5 . 0252 . 0 2 4 6 . 0 2 3 3 . 0 1 1 6 4 . 0 1 2 3 . 0 1 4 4 . 0 1 8 0

c

M c / 4 . 0 6 6 3 . 0 6 8 3 . 0 7 3 0 . 0 7 9 9 . 0 6 4 1 . 0 6 4 6 . 0 6 7 7 . 0 7 5 2 . 0 7 5 2 . 0 7 5 4 . 0 7 9 3 . 0836 . 0 7 6 5 . 0776 . 0 8 1 7 . 0 8 6 8 . 0 9 8 5 . 0 9 5 8 . 0 9 8 1 . 0 9 6 2 . 0 9 1 . 0 9 5 3 . 0 9 0 3 . 0 9 8 5 . 0 6 1 7 6 . 0 6 3 8 . 0 6 9 . 0 7 7 4 C X I O ^ - . 263 17. 03 1 9 . 4 3 2 7 . 30 - . 4 8 4. 80 1 1 . 20 2 6 . 5 0 - 1 . 075 5. 31 9 . 4 0 1 3 . 60 - . 5 2 1 . 7 5 5. 36 1 1 . 90 - . 22 - . 6 0 - . 6 3 - 3 . 8 8 - . 16 - 1 0 . - 8 . 4 - 7 . 87 - . 6 1 7 1 0 . 3 4 2 1 . 7 2 6 3 1 . 87 C j ^ l 0 3 0 3 . 11 3 . 71 5. 17 . 117 1. 235 2. 65 4. 84 - . 0 1 3. 63 6. 96 9. 50 0 3. 47 6 . 0 3 9. 46 . 022 4. 57 8. 70 12. 14 0 3. 6 6. 4 10. 10 - . 0 5 1 1. 238 2. 27 4. 352 C X I O ^ y 1.307 - 1 9 . 0 - 3 5 . 4 0 - 5 0 . 3 0 - . 194 - 1 6 . 3 5 - 3 1 . 10 - 5 4 . 5 0 0 - 8 . 54 - 2 2 . 3 0 - 3 7 . 0 0 0 - 9 . 5 - 1 9 . 0 - 3 3 . 50 - 1 . 0 0 - 2 . 50 - 1 0 . 0 0 - 2 0 . 30 - . 4 9 - 3 . 15 - 9 . 7 5 - 2 0 . 12 1.826 - 3 3 . 7 - 6 1 . 65 - 9 9 . 2 8 L / D 4 8 . 4 0 4 7 . 4 0 4 2 . 50 3 8 . 6 0 4 3 . 50 3 9 . 20 3 6 . 80 3 3 . 50 6 7 . 20 6 7 . 10 6 3 . 0 0 56. 80 6 7 . 0 0 6 4 . 50 6 1 . 30 5 1 . 10 5 6 . 80 5 5 . 4 0 52. 10 5 0 . 20 5 5 . 10 4 9 . 90 5 1 . 3 0 5 3 . 90 2 5 . 90 2 4 . 90 2 0 . 6 0 1 5 . 8 2 1 1

(19)

T A B L E 2 SIDESLIP T E S T S (contd. )

1 CASE

1 a= 2°, YEP's ^ = 0° 3° 60 9° a = 2°,iYEP's ^ = 0° 3° 6°

1 9°

o = 5°. YEP's ^ = 0° 3° 6° 9° 1 a= 5°,iYEP's^=0° 3°, 6° 9° a = 8°. YEP's ^=0° 3° 6° 9° a = 8°.iYEP's ^ = 0° 3° 6° 90 a = 8°. iY Wingtips

A=o

a = 8°. Y Wingtips

A=o

\ 6.C 25"

f

^'L = . 508 . 508 . 508 .4904 . 522 .5187 . 5129 . 5014 . 8083 . 8148 . 7982 . 7685 .83 . 8334 . 830 . 8123 1.0234 1. 01 1. 008 1. 000 1.1024 1. 1062 1.0986 1.0947 . 6682 . 6804 ^ D ! . 0126 .0136 . 016 . 0185 .0117 .01274 .01525 . 0184 . 0149 . 0157 . 0175 .0200 . 0161 . 01706 . 019 . 0214 .0198 . 0201 .0243 . 0232 .0235 . 0251 .0254 . 027 . 0589 .06 •*-^Mc/4 .0625 .0647 . 0679 . 0761 . 0594 . 0605 . 0643 .0739 . 0663 .0686 .071 .0786 .060 .0614 . 0641 . 072 . 0742 . 0747 .0781 . 0827 . 0600 .0602 .0634 . 0678 . 0406 .0337 C ^ X I O ^ -.041 15. 90 29.47 -. 68 4. 69 12. 714 28. 40 -.44 -. 06 6. 22 13. 38 - .67 1.21 5. 37 18.05 -. 78 . 04 1. 06 4. 94 -. 212 . 80 1. 327 5. 00 0 0

c^io'^

-. 023 3. 621 6.61 . 0752 3. 71 6. 40 -. 122 4. 64 7. 37 10. 49 3. 40 6. 24 10. 89 -. 524 5. 80 9. 78 14.83 . 063 4. 21 9. 59 14.66 . 093 . 181 C XIO^ y 2 . 2 1 -26.12 -54. 14 -92. 98 . 576 -30.13 -58. 37 -100.80 2. 95 -16.21 -41.62 -73. 23 1.24 -22. 27 -43.68 -81. 216 .52 -8. 22 -30.02 -56.30 . 196 -15. 57 -36.10 -67. 30 . 44 . 576 L/D 40. 30 37. 40 31.80 26. 50

44. 6 1

40. 7 33.60 27. 25 54. 20' 51.90 45. 60 38. 40 51. 50 48. 90 43.70 38. 00 51.70 50. 20 41.50 43. 15 47. 0 44. 10 43. 30

40. 5 1

11.35 11.34

(20)

X

w

V. !? 'O 1—1 l U •5*< ^.^ _o 1 p 'O J l U G X !

w

W

u

co CM t -+ CO 0 0 • * l ' l > o CD cn CO i n o , - 1 CM r H O i n o C>J _ i n co o CM CO

w

,^ o o Ö "b co o co II • « • CM CM T - l T H + r-f—1 T H l ' en o CM 1 i n ^ i n o t—1 T H O ^ i n r H H-> cn 0)

1

I-H Cd cn 13 G «lev i n CO o 1-1 + [ > i n i H 1 CM CO r-r H 1 0 0 • * LO o CM i H t H o ^ CO i n i H CO X ) o XI r.jtM H | N ^ I > ^ 1-H + CM co o t H 1 t H CO CO CM CO i n i n o t -T H O cn cn co 10 PH G CM II " o 0 0 O CO 11 •©• 1-H CD cn o TjH T:|< + 1-H -f-i n CD CO i n ' ^ 0 3 r 1 -* 00 cn o en t H t-H CM cn co co - ^ i n o o co cn i > co 1-H 1 - . o o i n ( M e n 0 3 CM 0 0 to • a to W " | ( N ^ I > •* 1 - H -1-CD CD CO 1 ' i * 1-H 1-H 1-H i n cn •* o 0 3 I > t H o en CM co -O G XI « I N > H > H > H rHlCMrHJN CM r H O CM + 0 0 CD 1 CO i n t -^ • * 0 3 i n o i H t n CM o cn 0 0 co to PH 0 i n II 0 "cD CM O CO II -©• cn ^ co + CM i n ^ 1 [ > co CM c~ •^ OO ^ _o CO CO 0 0 o co r H i n co x) o X3 H|CV >H 0 3 i n 0 3 r H + i n O O 1-H •* CO ^ 'S* co co o i - H en M o i n co CD tn P H W l x t > o ^' -t-co co CD CD l' ' i ' O o CD i n o ^ O en co co O o 1 - . i n tn P H W rnlN H N i n CD t ~ o co + 0 0 CM CM 1 c-i n CD co CM c-o CD i n "* _o co • * 0 3 cn P H W t^ O eo 11 ö " i n co o CD 11 -e-0 -e-0 0 3 0 3 co r H + • * cn i - I 1 T H O i n 1-H t - H r H i n O i n i n o CD ^ t -cn 1 3 o . Q I H | M i» CD • ^ 1 CD CO c^ cn co + + co c^ 1-H c o co" CM 1 1 r H cc • * CM 0 3 0 0 CD CO CO i n i > i n o o CO r)< CD i n • * i n o o ^ cn c- eo cn t -EP' s i bod s >^«ÏN r^|N O CO O CO -t-CD CM" 1 i n • * l O CD 0 0 co 00 o CO '^ "* o o o 1 *** [0 PH w •^ o co " o " II 1 •©• CM co r~ + CM i r -i - H CD cn o co i n o i n T H i n o CO co co cn T) G XI « | C ^ cn co 0 3 1 - H -1-CM eo t H i t - H • * CO t -co 1 - H 0 3 o CD i n • * o c-CM O i H CO PM W co CO i n -1- r-1-H' 1-H ^ 1-H cn CO co O i n co i n o 0 3 0 0 i > co • ü G X I r.|<M > ^ >H >H •* CO cn 1 - H + CO 1-H 1 CM 0 0 CO i n i n CD o CO i > co o 0 0 rj< c-co P H W >H o i n 11 Ö G " II CD O CO + t -•* • * l' i n i n i n ^ ' ^ i o co CM co o '^ i n co 13 o XI HlC^ co co o CM + (S) • * t H c^ i n •>!< i n • * cn CD o i n r -co o i n • * r-co P H W 'ï' CM CO -1-0 -1-0 CD l ' 0 3 CO Xt< CO co • * o i n 0 0 co o -* i n cn 13 G XI HcH H « H | C 1 i n co OO , - H + eg i > cn i ' 0 0 CD •*" CM i n i n o 0 3 i n i H O o c q '^ to P H w >H o -CM 11 o II co O i H + CO CM CO 1 CO en CO 1-H cn i n ^ o 0 0 CD 1-H o r H 0 3 CO to G XI H|<V cn 1 CM i-H CD c n •*' +" i H 1 -f-i n T}< CD CD 0 3 CM 1 1 CM T»< cn i n c~ co' CM CD 1-H I C - 0 0 i n ^ o o 0 3 0 3 i n c -r H i H o o CM C -CO O • * CO t n - S P H ^ w •^ H | ( M >^ >^ >^

(21)

TABLE 3 BANK TESTS (contd. ) 3 C A S E 4 = 4 ° , a = 0 ° . Y E P ' s Y i b o d s i Y i b o d s 4= 2°, a = 0 ° , Y E P ' s Y i b o d s i Y i b o d s ^ = 2 ° , a= 2°, Y E P ' s Y i b o d s i Y E P ' s i Y i b o d s (j>= 2 ° . 0 = 5 0 , Y E P ' s Y i b o d s i Y i E P ' s i Y i b o d s 4=2, Q= 8°. Y E P ' s Y i b o d s i Y E P ' s i Y i b o d s <^= 6 ° 1 4 ' , 0 = 8 ° Y E P ' s Y i b o d s 6*^26' i Y E P ' s i Y i b o d s <j,= 6 O I 8 ' , Q = 5 ° . Y E P ' s Y i b o d s 6 ° 2 0 ' i Y E P ' s i Y i b o d s b 0 2. 1 1

1

0 2 5 "

r

4. 0 2 5 " a t l o w e s t t i p ( ^ L . 209 . 146 . 1 5 1 . 1 8 1 . 125 . 129 . 4 2 1 . 2 8 8 . 4 1 8 . 2 8 9 . 8 2 1 . 5 8 1 . 8 1 7 . 569 1. 12 . 84 1. 14 . 836 . 8 8 7 . 6 6 5 . 8 8 4 . 6 6 1 . 6 6 8 4 . 4 9 5 . 6 6 3 . 4 7 3

S

. 016 . 0 1 0 7 . 0109 . O i l . 0 1 0 5 . 0 0 9 9 7 . 0156 . 0 1 6 2 . 0 1 5 7 . 0162 . 0 2 7 5 . 0 3 1 . 0 2 7 7 . 0 3 4 2 . 0 4 3 . 057 . 0439 . 0574 . 0502 . 0616 . 05 . 0 6 1 4 . 0 3 1 . 0 3 5 3 . 0 3 0 9 . 0 3 5 1

"Slc/4

. 0 5 7 1 . 0 5 3 2 . 0 5 4 3 . 0 5 4 1 . 0 5 1 1 . 0 5 2 1 . 054 . 0 4 3 . 0 5 4 3 . 0 4 5 . 0 7 3 8 . 0 4 3 7 . 062 . 05 . 107 . 0 6 2 . 1186 . 0 7 1 4 . 0 5 0 5 . 0 3 2 1 . 0 5 6 6 . 0 4 0 5 . 0 4 8 3 . 0 3 7 3 . 0 5 2 8 . 04

-S

8. 9 4. 17 - 1 . 6 0 7 4. 6 - 1 . 0 0 8 - . 765 2 1 . 33 . 6 7 3 2 1 . 16 . 67 4 6 . 18 3 . 724 4 4 . 92 2 . 0 8 6 1 . 92 6. 545 6 4 . 22 9. 28 4 8 . 16 5 . 0 2 4 7 . 7 4 . 93 4 0 . 08 6. 23 4 0 . 28 6. 273 ^ N - . 57 - . 191 - . 127 - . 477 - . 02 - . 0 1 8 7 - . 409 - . 0 1 2 6 - . 4 4 1 - . 0136 +. 313 - . 578 - . 4 1 6 - . 4 2 6 - 1 . 9 5 7 - . 797 - 1 . 21 - 5 . 39 - 4 . 6 1 - . 735 - 1 . 93 - . 64 - 1 . 3 7 6 - . 237 - 1 . 44 - . 28 -HC y + 8 . 25 + 1. 44 + 1. 4 1 + 6 . 22 + 1. 0 0 8 +. 7 6 8 -(-10. 7 1 +. 223 + 12. 21 +. 1187 + 1 3 . 8 5 + 2 . 3 3 6 + 1 5 . 1 7 + 2 . 093 + 1 1 . 87 + 3 . 78 + 9 . 41 + 1. 42 + 3 9 . 4 + 4 . 37 + 3 7 . 3 4 + 2 . 64 + 3 2 . 5 4 + 1. 75 + 3 4 . 7 5 + 1 . 4 2 1

(22)

TABLE 3 BANK TESTS (contd. ) ^ 1 0 ^

' r " \

CASE 9= 6018', a = 2 ° . Y E P ' s Y i bods 6°20' i Y E P ' s i Y i bods (^=4. a = 29 Y E P ' s Y i bods i Y E P ' s i Y i bods <^= 4, a = 5 ° . Y E P ' s Y i bods i Y E P ' s i Y i bods 9 = 4 . a = 8 ° . Y E P ' s Y i bods i Y E P ' s i Y i bods (/I = 2 ° , a = 8 ° , Y E P ' s Y i bods i Y E P ' s i Y i bods <i>= 20, a = 5 ° , Y E P ' s Y i bods i Y i E P ' s i Y i bods </>= 2 ° . o = 2 ° , Y E P ' s Y i bods i Y E P ' s i Y i bods ^ 4 . 0 2 5 " 1 ^ L . 4 0 7 . 287 . 4 0 . 281 . 4 3 . 287 . 4 2 . 3 . 691 . 665 . 715 . 5 . 921 . 7 . 93 . 425 . 986 . 696 1. 00 . 7 . 7 5 . 5 . 737 . 49 . 4 . 291 . 428 . 29 ^ D . 019 . 0192 . 0189 . 0187 . 0181 . 0 1 8 5 . 0 1 7 5 . 0 1 8 9 . 0292 . 0348 . 0292 . 0353 .046 . 0 5 9 4 . 0 4 6 7 .0606 . 0 4 6 4 . 0 6 0 5 . 0 4 4 5 .0606 . 0284 .0346 . 0 2 9 3 . 0 3 5 1 . 0 1 8 1 .0169 . 017 .01824 " ^ M c / 4 . 0 5 0 7 . 0444 . 054 . 0 4 8 . 0506 . 0437 . 0542 .0466 . 0527 . 0384 . 0553 . 0 4 1 4 . 0588 . 0371 . 0654 . 0447 . 0696 . 0404 . 0792 . 0455 . 062 . 041 . 0 6 6 .0459 . 057 . 0456 . 057 . 0485 - ^ 1 21. 33 2. 58 19. 67 1. 11 24. 51 2. 96 22. 13 2. 134 37. 07 3.54 35. 08 4. 34 4 8 . 5 9 4. 36 4 4 . 4 5 3. 81 39. 65 4. 2 36. 1 4.22 33. 45 4. 19 31. 55 4 . 4 20. 90 2. 73 18. 28 2. 43 1

c

-. 946 -. 286 - 1 . 234 -. 032 -. 849 +. 272 - 1 . 234 +. 30 - 1 . 1 5 7 +.2735 - 1 . 262 +. 557 - 3 . 0 5 3 -. 079 - 2 . 49 -. 705 - 2 . 1 -. 127 -. 705 -. 323 -. 955 -. 073 - . 6 -. 288 - . 8 7 +. 031 -. 928 - . 0 4 0 4 +C y + 2 3 . 1 8 + . 8 7 1 + 2 3 . 8 1 + . 3 9 4 +21. 88 +. 244 +22. 18 - . 38 + 2 8 . 7 4 +.464 +30. 24 +. 209 +30. 13 +2. 4 +34.66 +4. 72 + 17. 24 +3.087 + 15.65 +4. 08 + 16.04 + 1. 5 + 18. 91 + 1. 853 + 15. 94 +. 202 +16.53 +. 134

(23)

TABLE 3 BANK T E S T S (contd. ) ^ , . 3 1 CASE 4= 5 ° 3 7 ' . a= 0°. Y E P ' s Y i bods i Y i bods (?= 5 ° 3 3 ' , a = 2°, Y E P ' s Y i bods i Y E P ' s 1 i Y i bods 4= 5 0 3 3 ' , 0 = 50, Y E P ' s Y i bods i Y E P ' s i Y i bods 4= 5 ° 3 3 ' , a = 8 ° , Y E P ' s Y i bods i Y E P ' s 1 i Y i bods 1 <(,= 4 0 3 ' , a = 8 ° , Y E P ' s Y i bods i Y E P ' s i Y i bods 4= 4 ° 3 ' . 0 = 5 ° , Y E P ' s Y i bods i Y E P ' s i Y i bods 4= 4 ° 3 ' . 0 = 20, Y E P ' s Y i bods i Y E P ' s i Y i bods h o 6 . 0 2 5 " at lowest tip ^ L . 271 . 17 . 1708 . 4209 . 278 . 401 . 277 . 665 . 4 1 . 6 5 . 453 . 888 . 632 . 857 . 63 . 866 . 633 . 855 . 6 2 4 . 666 . 458 . 653 . 451 . 4 2 4 . 2 8 . 4 . 265 ^ D . 0147 . 0123 . 0125 . 0197 . 0193 . 0194 . 0194 . 0301 . 0 3 5 8 . 03 . 0353 . 0442 . 0584 . 047 . 0582 . 046 . 058 . 0466 . 058 . 0309 . 0351 . 0309 . 0348 . 02 . 0193 . 0194 . 0192 " ^ M c / 4 . 0606 . 0547 . 0563 . 056 . 0472 . 056 . 049 . 053 . 039 . 0565 . 0395 . 0484 . 0478 . 0536 . 0382 . 0483 . 0328 . 0519 . 048 . 0525 . 0 3 8 5 . 0567 . 0433 . 055 . 0476 . 0567 . 0337

-S

3 1 . 4 8 1. 342 1. 114 18. 66 1. 772 15. 87 1.76 29. 84 2. 49 26. 91 3. 044 35. 69 3. 96 34. 8 3. 016 + 3 9 . 0 1 3. 90 30. 99 2. 97 28. 72 2. 58 24. 4 2. 88 17. 8 2. 58 14. 94 2. 32 ^ N - 1 . 4 8 - . 0 7 3 - . 155 - 1 . 72 - . 0 3 5 - 2 . 0 - . 063 - 2 . 67 - . 181 - 2 . 8 7 - . 2 2 5 - 3 . 3 7 - . 3 7 - 3 . 5 - . 4 0 8 - 2 . 6 2 - . 10 - 2 . 6 4 - . 226 - 2 . 0 4 - . 132 - 2 . 3 7 - . 2 2 3 - 1 . 312 - . 0 4 - 1 . 57 - . 0 4 2 +C y +22. 45 +. 599 +. 752 +31.05 +. 452 +30.25 +. 763 +45. 05 +2. 13 +46. 08 + 2. 11 +50. 06 1 +3. 24 +50. 3 +3. 56 +42. 83 +2. 73 +42. 24 +3. 07 +35. 875 - 2 . 28 +38. 21 + 1. 661 + 26. 79 +. 491 + 25. 21 +. 605

(24)

TABLE 3 BANK TESTS (contd. ) ^ , . 3 — — — ^ — . — . ^ P\ i u r " s j C A S E Lp= 2°. a= 2°. YEP's Yi bods iY EP's iYi bods i^= 2"=. a= 5°. YEP's Yi bods iY EP's iYi bods 0 = 2 ° . o = 8°. YEP's Yi bods iY EP's iYi bods

K

6. 025" ^ L . 448 . 285 . 433 . 288 . 7 . 472 . 757 . 472 . 937 . 656 . 944 . 647

s

.0182 . 0187 . 0174 . 0188 . 0275 . 035 .0262 .0348 . 0373 . 0587 .041 .0578 "^Mc/4 . 057 ^' . 0507 . 058 . 05 . 0557 . 0386 . 0594 . 0429 . 0571 . 0625 . 0397 - « 1 15. 82 1. 82 22. 83 2. 032 25. 74 1. 51 22. 10 2. 654 34. 14 1. 127 27. 49 2. 03 ^ N -1. 17 -.04 -1. 39 -.04 -1. 306 -. 058 -. 937 -. 142 -2. 08 -. 063 -. 742 -. 245 +C y +20. 12 +. 556 + 17 +. 787 +26. 97 + 1. 22 +27. 36 + 1. 25 + 24. 38 + 2. 0 +24. 86 +2. 48

(25)

FIG. 1. C L O S E D CONFIGURATION USING " H A L F CLARK Y " ENDPLATB^S h = 2 " , a = 6 ° , Z E R O S I D E S L I P AND BANK

P

FIG. 2. C L O S E D CONFIGURATION USING CLARK Y E N D P L A T E S hp = 2 " , a = 6 ° , Z E R O S I D E S L I P AND BANK

(26)

FIG. 3. BANKED CONFIGURATION WITH CLARK Y ENDPLATES h = 4", a = 0«, ;3 = 0°. 4-^6° LIFT L SIDEFORCE Y 1 PITCHING MOMENT M YAWING MOMENT N ROLLING MOMENT i /_t-*-_DRAG D

(27)

FIG. 5(a). STRUT W A K E O N WING U P P E R SURFACE _{FIG. 5(b) E F F E C T OF PARTIALLY SEALING T H E} T O P OF THE STRUT ON THE W A K E O V E R T H E WING UPPER SURFACE

(28)

1-6 1-2 l O l U 8 •6 /

RIGID STRUTS CALCULATED Ql = l 9 0 2 / ° , / s = 12'' IH= 2 025, <^= i/r=0° CLARK Y ENDPLATES (CLOSED CONFIGURATION) 4 6 0^° lO hp»6 0 2 5

FIG.6. COMPARISON BETWEEN ESTIMATED STRUT FLEXIBILITY CORRECTION TO FLEXIBLE STRUTS LIFT CURVE

AND THAT MEASURED FOR RIGID STRUTS.

» CLARK V ENDPLATES o HALF CLARK Y ENDPLATES * CLARK Y W I N G T I P BODIES o HALF CLARK Y WINGTIP BODIES • REF 2 FLAT ENDPLATES » REF 6 BASIC WING Vc •= 2 2 %

I I I

FIG. 7 (c) LIFT CURVE

hp= 4 0 2 5

FIG. 7(a) FIG. 7(b)

(29)

F I G . 7 ( d ) POSITION O F TRAILING V O R T I C E S 5 " A F T O F WING TRAILING E D G E . C L A R K E Y

a = 6 ° , p - <> = 0 W I N G T I P BODIES, hp = 4 '

(30)

O I 0 2

FIG. 8 (a)

VARIAnON OF LIFT WITH HEIGHT ABOVE GROUND

12

\& «

2

-« CLARK Y ENDPLATES » CLARK Y WINGTIP BODES o HALF CLARK Y WINGTIP BODIES a HALF CLARK Y ENDPLATES • REF 5 No ENDPLATES OR ^

WINGTIP BODIES

'12

OS •10

RG. 8(b)

VARIATION OF LIFT WITH HEIGHT ABOVE GROUND.

hp = 2- 02S FIG 9(a) DRAG CURVE. -10 -OB Itf 06 -0 4 0 2 -a hp = 4 0 2 5 » CLARK Y ENDPLATES » CLARK Y WINGTIP BODIES o HALF CLARK Y WINGTIP BODIES Q HALF CLARK Y ENDPLATES

'>P-602S" FIG. 9(b) 8 10 - 2 0 DRAG CURVES 2 RG 9(c) 10

(31)

'12 •lO -oa 11? 0 6 0 4 • 0 2 « CLARK Y ENDPLATES 4 CLARK Y WINGTIP BODIES

0 5 . c - 2 " h ^ L « - 8 ' • < - 5 ' • « . 2 10 _os "P/r 10

FIG. IOCQ) FIG. 10(b)

VARIATION OF DRAG WITH INQDENCE AND HEIGHT ABOVE GROUND.

•10 • 0 8 0 6

!<?

• 0 4 • 0 2

o HALF CLARK Y ENDPLATES a HALF CLARK Y WINGTIP BODIES

0 5 10 <x-2° 1 — • " _{- - >} « C . S ' ^ - 2 OS 10 "P/B "P/b FIG: 10(c) FIG. 10(d)

VARIATION OF DRAG WITH INQDENCE AND HEIGHT ABOVE GROUND.

12 'O6 I1P06 0 4 • 0 2 t i p . 2 0 2 S » CLARK Y ENDPLATES » CLARK Y WINGTIP BODIES o HALF CLARK Y WINGTIP BODIES o HALF CLARK Y ENDPLATES

FIG.II(a) 6 _ B 1 0 1-2 1 4 U^ DRAG CURVES. I>p>4 0 2 5 " / FIG.Il(b)

(32)

•12 r •to os II? o* 0 4 h p - 5 025 » CLARK Y ENDPLATES » CLARK Y WINGTIP BODIES D HALF CLARK Y ENDPLATES o HALF CLARK Y WINGTIP BODIES

8 l O 12 C L FIG. 11(c) DRAG CURVE 2 0 hp = 2 0 2 5 IQ 12 1-4 FIG. 12(a)

VARIATION OF PITCHING MOMENT WITH LIFT. ^ - 05 lo - l O L 1 0 1 2 >• CLARK Y ENDPLATES ' CLARK Y WINGTIP BODIES

" HALF CLARK Y WINGTIP BODIES

o HALF CLARK Y ENDPLATES

• i p - ó 0 2 5

FIG. 12(b) FIG 12(c) VARIATION OF PITCHING MOMENT WITH LIFT

os

U.2'

CLARK Y ENDPLATES HALF CLARK Y ENDPLATES

FIG. 13(a) FIG. 13(b)

(33)

""/s icj o os IC 0 os lO 1 1

^.^=rz

"y^

-/

CLARK Y WINGTIP BODIES

O r — 2° ~^:

'•1

7

os :==" / "% •lO i -"=^7^*^ /

HALF CLARK Y WINGTIP E

FIG. 13(c) FIG 13(d)

VARIATION OF PITCHING MOMENT WITH INCIDENCE AND HEIGHT ABOVE GROUND.

CLARK Y ENDPLATES HALF CLARK Y ENDPLATES

Sf

t

•OS 10 o OS ID

FIG. 14 (a) FIG. 14(b) CENTRE OF PRESSURE SHIFT DUE TO HEIGHT ABOVE GROUND.

CLARK Y WINGTIP BODIES HALF CLARK Y WINGTIP BODIES

)?1"

34 32 •30 ' k - i " - • < - S " 0 5 ••P/B FIG. 14(c) •OS lO "P/E FIG. 14 ;d) CENTRE OF PRESSURE SHIFT DUE TO HEIGHT ABOVE GROUND.

(34)

CLARK Y ENDPLXTES I20 lOO 8 0 H ^ ^ O 4 0 2 0 'P/K= 039 o 2 4 6 B 1 0 12 1 4 1-6

FIG. 15(a) VARIATION OF LIFT/DRAG RATIO WITH LIFT OOEFRQENT AND HEIGHT.

3 0

20

10

CLARK Y WINGTIP BODIES

- I L _ •«P/5--039 - " ? € = 077S "P/g =1145 I I o 2 4 -6 _ 8

RG.I5 (b) LIFT/DRAG RATIOS ( C O N T D )

1 0 1-2 l ^

100 r

HALF CLARK Y ENDPLATES

8 0 -60 Je 4 0 P t = 0 4 0 5 •"?/£= OSOS S/fe= I20S 20 1 0 12 •2 4 •ó •e

FIG 15(c) LIFT/DRAG RATIOS (CONTD)

16 3 0 20 10 8 6 4 2 O '02B h p t = 0 8 3 4 •>p/^.- 1665 « •<?/(•= 0 4 0 5 | "> PRESENT TESTS ' •'(jfj= 080S> HALF CLARK Y ° V = I205J "WINGTIP BODIES • REF S BASIC WING Vc " 12% • REF 6 BASIC WING Vc = 2 2 %

O 2 •6 _ 8

C L

1 0 1-2 1-4

(35)

d . DEPTH OF ENDPLATE AT QUARTER CHORD C/4

llP O'

083 « i l l CLARK Y ENDPLATES

•167 " ill CLARK Y ENDPLATES •085 o 2// HALF CLARK Y ENDPLATES •167 o 4 / / HALF CLARK Y ENDPLATES •lO • REF 5 FLAT ENDPLATES

•>p-6 0 2 5 "

4 _ -6 •8 1 0

OUT OF GROUND EFFECT

FIG 16. FIG.I7. DRAG CURVES FOR PARALLEL ENDPLATE CONFIGURATION.

.IP IS

•f/c - 0 8 3

CLARK Y ENDPLATES ^ p / g - 1145 HALF CLARK Y ENDPLATES " p / ^ - 12 » FROM REF S •'fc " lO "p/^» 113

FLAT ENDPLATES

O/c- 167

CLARK Y ENDPLATES Xp/r- 1145 HALF CLARK Y ENDPLATES ""p/^- 12 FROM REF 5 «1/^ • 15 V / ^ " 113 FLAT ENDPLATES

4 _6

C L

10 12 FIG. ISCa) FIG. 18 (b)

LIFT/DRAG RATIOS FOR PARALLEL ENDPLATE CONFIGURATION. q.

•4 6

h p - 6 025

FIG. 19.

OS3 « 2 MRALLEL CLARK Y ENDPLATES 167 » 4 ' PARALLEL CLARK Y ENDPLATES OB3 o 2' PARALLEL CLARK Y ENDPLATES 167 o 4" PARALLEL CLARK Y ENDPLATES

D 2 / ^ ^ OUT OF q. 4 6 n" " GROUND •8 1-EFFECT FIG. 20.

(36)

1-2 ia' 6 FROM REF 2 FLAT ENDPLATES <l/c- 083 HALF CLARK Y ENDPLATES d/c - • OB3 FLAT ENDPLATES VE 0 - 3

FIG.2I. VARIATION OF LIFT WITH HEIGHT ABOVE GROUND (PARALLEL ENDPLATES)

• PRESENT TESTS <l/c - • 167 e PRESENT TESTS <l/c« 0 8 3

1

. • 4 . -' -' p - 2 02S" CLARK Y ENDPLATES \o' . ^ - 8 ° ' ' p . 2 0 2 5 HALF CLARK Y ENDPLATES

2 4 6 8 lO 0 2 4 6 8

FIG 22(a) FIG 22(b) VARIATIONS OF LIFT WITH SIDESLIP AT CONSTANT INCIDENCE.

4

10-l<p-4 0 2 5 CLARK Y ENDPLATES -r- ^.S' '>p.4 025 HALF CLARK Y ENDPLATES

« — ^ . 8 ' '

4 6 8 10 2 4 6

FIG 22(0) FIG 22(d) VARIATIONS OF LIFT (CONTCI)

(37)

•>p-6 0 2 5 CLARK Y ENDPLATES

• • p s S O i S " HALF CLARK Y ENDPLATES

l O lO" 6 •2 -l i ^ e <.o' 4 6 FIG 22(,e) 8 lO VARIATIONS OF LIFT. P - O U p . 2-025 /B"9J ^ ' o X h p . é 02S FIG. 23 (a) 4 6 FIG 22(f) FIG. 23(b) LIFT CURVES. h p - 2 0 2 5 CLARK Y ENDPLATES FIG. 24(a) HALF CLARK Y FIG. 24(b) VARIATIONS OF DRAG WITH SIDESLIP AT CONSTANT INCIDENCE.

(38)

•ip-4 02S

CLARK Y ENDPLATES HALF CLARK Y ENDPLATES

FIG.24'(c) FIG 24(d) VARIATIONS OF DRAG (CONTD)

''P-602S '

CLARK Y ENDPLATES HALF CLARK Y ENDPLATES

FIG. 24(«) VARIATIONS OF DRAG h, - 2 0 2 5 " 3 0 CLARK Y ENDPLATES O 2 4 6 8 10 12

0 2 4 10 12

FIG. 25(a) FIG. 25(b)

(39)

•"p " 4 025

CLARK Y ENDPLATES

6

^ . t - 8 "

FIG. 25(c) FIG. 25(d) VARIATION OF LIFT/DRAG RATIO CONTD

h. - 6 025

4 6 8 0 12 0 2 4 6 8

^'' f>° FIG. 25(e) FIG. 25(f)

VARIATION OF LIFT/DRAG RATIO.

02 0 4 0 2 ' 4 f>' 6 8 IC lO - 0 8 - 2 0 CLARK Y ENDPLATES . o<-a° ,c - 0 2 - 0 4 - 0 6 - 0 8 - l O - 12 ^• 2 4 6 8 C " ^

--'t

^ - 2 '

^ 5

-h p . 2 0 2 5 '

FIG 26(a) FIG. 26(b)

(40)

o O - 0 2 - 0 4 - 0 6 D -• 2 4 5 8 IC CLARK Y ENDPLATES •lO'r " - . < . S°

.5 lo

h.-4 025

FIG. 26(c) FIG. 26(d) VARIATION OF PITCHING MOMENT (CONTD)

h p . 6 02S

FIG. 26(e) FIG. 26(f) VARIATION OF PITCHING MOMENT

g

•<-o'

^ - 5 °

h p . 2 025

FIG. 27 (q) FIG 27(b) ROLLING MOMENTS DUE TO SIDESLIP

(41)

<K=S°

l>p . 4 0 2 s ' '

FIG 27(c) FIG. 27(d) ROLUNG MOMENTS DUE TO SIDESLIR

FROM REF 5 , ^ - 2

FLAT ENDPLATES

l i p > 6 0 2 S

FIG. 27(e) FIG 27(f) ROLLING MOMENT DUE TO SIDESLIR

l<p m 2- 0 2 S

i j

CLARK Y ENDPLATES

Fia28(a)

FIG28(l})

* - 5 "

— 2

(42)

hp = 4 025

FIG.28(c) FIG.28(d) YAWING MOMENTS (CONTD)

•>p=6 025

RG.28(e)

/ « r - 8°

• « r . s "

« • 2

-HALF CLARK Y ENDPLATES

FROM REF 5 .< - 2 FLAT ENDPLATES N i / i = 0 II O 2 4 6 FIG 28 (f) YAWING MOMENTS ^ • 2 02S' ^ ^ . . CLARK Y ENDPLATES \ K . 2° HALF CLARK Y ENDPLATES

FIG29(a) FIG 29(b) SIDEFORCE DUE TO SIDESLIR

(43)

hp . 4 02S

V = S °

O

FIG. 29(c) FIG. 29(d) SIDEFORCE DUE TO SIDESLIR

FIG. 29 (e) FIG.29(f) SIDEFORCE DUE TO SIDESLIR

\o' « 4'2 ho-207S ^.A' h o » 2 l 3 5 " ^ • 6 ° 3 o ' t i o " 2 2 " • • 2 ° ) 1 . 4 » l WINGTIP ;.6'3o'r°»'" tio-HEIGHT OF WING '/4 AT LOWEST TIP nG.30(a) PLANE ( V I E W F R O M F R O N T ) LIFT CURVES RG30(b)

(44)

I o icr' <*-=2° 1^,-4 118* « - ^ * = 4 ° h o - 4 2 0 5 ' » ^ ^ * - 6 V . h o = 4 - 3 l 7 ' • ^ - 4 ° » 2 ° \ WINGTIP •P'b'te' / B O D I E S l O CLARK Y ENDPLATES 4 6 a' FIG.30(c) CLARK Y ENDPLATES I L RG SO (e) - J ID LIFT CURVES. * » 2 ho = 6 1176 » 5 ° 3 5 ' h o = 6 - 2 9 7 " = 4 ° h o = 6 - 2 0 5 " * - 2 ° * = 5 ° 3 5 ' » 4 ' WINGTIP BODIES * - 2 h o - 4 0 7 7 6 ^ = 4 ° h o = 4 l 2 5 ' * = 6 ' ' 2 0 ' h o - 4 l 8 7 ' ( p - 4 ° » 2 ' ' \ WINGTIP * = 6 ' ' Z O / B O D I E S

HALF CLARK Y ENDPLATES lO FIG. 3 0 (d) * » 2 h o - 6 0 7 7 6 * - 5 ° 3 s ' h o = 6 167" • * « 4 ' ' h o - 6 1 2 5 ' * " 2 ° , 1 WINGTIP * " 5 3 5 » 4 f BODIES _l lO LIFT CURVES.

_| lO FIG. 3 0 (f) h o > 2 0 2 5 NOMINAL 0 6 OS 0 4 0 3 0 2 : : = ^

°'t

CLARK Y ENDPLATES 4 6 FIG. 31(a) lO DRAG CURVES. 6 3 0

(45)

h o - 2 025 NOMINAL 0 6 OS 0 4 ' 0 2 0 6

HALF CLARK Y ENDPLATES

4 6 FIG. 31(c) - ^ ' CLARK Y ENDPLATES 4 6 FIG. 31(e) FIG. 31(d) DRAG CURVES. h o - 4 02S NOMINAL

CLARK Y WINGTIP BODIES

4 6

FIG. 31(f) DRAG CURVES

iJ^

l>o>4 02S NOMINAL

't

4 6

FIG. 31(9)

o - o o

/ • - 6 ° 2 0 . 4 »

HALF CLARK Y WINGTIP BODIES

10

FIG. 31 ( DRAG CURVES

(46)

lio-6'025 NOMINAL - 0 2 01J-CLARK Y ENDPLATES _J L_ 2 4 6 8 10 • . S ' 3 S . 4 " » 2 ' FIG. 31(1) FIG.3l(j) DRAG CURVES. h o - 6 0 2 5 " NOMINAL 0 6 OS 0 4 0 3 o - c ' .0 * - S ° 3 5 t 4 '

'i

_{4 6} FIG.3l(k) •-5'3S;4'>i2° FIG. 3I(<) DRAG CURVES q. 6 q. 6 ho-2025 NOMINAL •10 * - 6 ° 3 Ö > WINGTIP BODIES ƒ - 06 [- / > ENDPLATES <t>'2 ho-2^025 NOMINAL FIG. 32 (a) HALF CLARK Y FIG. 32 (b) WINGTIP BODIES ENDPLATES

(47)

q. 4 6 8 I O 12 1 ; 1 1 h o - 4 0 2 5 NOMINAL C 2 -• >: 4° > ENDPLATES I

ƒ

FIG. 32(0) - l O q. •2 4 6 -1 1 r ho = 4 025" NOMINAL 8 1 0 12 4 •> WINGTIP BODIES * . 2 " ' , * - 6" 20' HALF CLARK Y FIG. 32(d) ,^.4<> > ENDPLATES * - 2 - > , • 0 4 •08 • 1 2 ' -q. 4 6 1 0 12 —1 1 h o - 6 0 2 5 NOMINAL • - 2 " , , ^ . 4 ' ' '> Wir;GT|P BODIES = 5° 35 * = 5°35 AND ^ • 0 2 -S ENDPLATE-S FIG. 32(e) / -' - 1 0

y

^ ' — ' • ) . 1 0 1-2 h o - 6 0 2 S NOMINAL <*- 5 35 * - 4 ' ' ^ WINGTIP BODIES HALF CLARK Y FIG. 3 2 ( f ) 5" 35 AND 4 " • * a -h o - 2 025 NOMINAL

• FROM REF S BASIC WING

FIG. 33 a)

CLARK Y ENDPLATES

FIG. 33(b) ROLLING MOMENTS DUE TO BANK.

h o - 6 025

(48)

lu

h o - 2 0 2 5 NOMINAL

FIG. 33 (d)

ho=4 025 NOMINAL HALF CLARK Y ENDPLATES

FIG. 33 (e)

ROLLING MOMENTS DUE TO BANK.

" 0 - 6 025 NOMINAL FIG. 3 3 f 4 • « - 5 " *• ^

h o - 2 02S NOMINAL h o - 4 0 2 5 NOMINAL ho . f t o2S NOMINAL CLARK Y WINGTIP BODIES

FIG.33(g) FIG.33(h) FIG.33(i) ROLLING MOMENTS DUE TO BANK.

— • K - O " O lu h o - 2 0 2 s NOMINAL FIG.33(j) h o ^ 4 0 2 5 NOMINAL HALF CLARK Y WINGTIP BODIES

FIG. 3 3 (k)

ROLLING MOMENTS DUE TO BANK

e

••a».<-5°»8°

h o - 6 0 2 s NOMINAL

(49)

FIG. 34(a)

hos4 02S NOMINAL

CLARK Y ENDPLATES

FIG. 34(b)

YAWING MOMENTS DUE TO BANK.

'<o.6 025" NOMINAL FIG. 34(c) o<-2 «C.5° o<-a h o - 2 02s NOMINAL FIG. 34(d) 4 1 r

5N

V _{' c<.5*}o<.2 h o s 4 0 2 S NOMINAL HALF CLARK Y ENDPLATES

RG.34<e)

h o - 6 025 NOMINAL FIG. 3 4 ( f ) - 5 <-ho»2 025 NOMINAL FIG. 34(9) 4 ^ ^ \ ot-8" ho =4 025 NOMINAL

CLARK Y WINGTIP BODIES

FIG.34(h)

ho = 6 025 NOMINAL