3 . . copy No. . -

- - R M No. A8J2 1

RESEARCH MEMORANDUM WIND-TUNNEL INVESTIGATION OF HORIZONTAL T A U .

IV - UNSWEPT PLAN FORM OF ASPECT RATIO 2-

AND A TWO-DIMENSIONAL MODEL

By Jules E. Dods, Jr.

.. ." .

A m e s Aeronautical Laboratory Moffett Field, Calif.

NATIONAL ADVISORY COMMITTEE - FOR AERONAUTICS

WASHINGTON December X, 1948

By Jules B. Ikds, Jr.

The results of a wind-tunnel investigation of the lowaped aerodynamic characteristics of a horieontal-tail model of aspect r a t i o 2 having an "unswept " p h n f o m l and of a two-dimsnsioml model are presented. These data supplement previously reported results of t es t s on =wept and swep-ack llhodels of aspect ratios 3, 4.5, - 6.

The twc-dimansiond model, which has the stme a i r f o i l section as d l t h e models tested in this series (RAW &AOlO), provides data which can be used as the basis f o r comput-lng the the- dimsnsional lift; and hinge-mmnt prsslaters by the l i f t m u r f a c e - theory procedure.

Test results m e presented for the M e l s with esd without standard roughness applied t o their leading edges, w i t h sealed and unsealed radius-nose,eleVstors, esd for a Reynolds n&er ranging from 3.0 t o 7.5 x 10 . The testa included msasuremsnts of the model l i f t and pitching mnent, elevator hinge mane&, and pressure difference across the elevator nose seal.

The major effect of standard l e a d w d g e roughness wa8 t o increase (positively) the rate of change of hi-msnt coefficient with angle of attack of the model of aspect ra t io 2. Removal of the elevator nose seal reduced the lift effectiveness of the elevator f o r the tw~inrsnsional model. I?o significant scale effects were encountered for eikher -el through the Reynolds number range investigated.

c . 1-

2

A systematic investigation of the crmtrol-swface chcracteri6- t ics , pa3cticularl.y the hinge-mmnt paramsters, of horizontal-tail eurfaces has been mdertabn by the RACA to provide experimental results for a comparison with those parameters computed by lirrting- surface-theory procedures.

Ekperimentcil reaulta obtained from w i n d ; t u n n e l tests of unsuept and 35O 6wept-back plan-.iorm mdels of aspect ratfos 3, 4.5, and 6 are presented tn references I, 2, bnd 3. me present report extends the experimental data to include an aspect ratio of 2 and, in addition, presents section data which are neceesary for the Ufting-surface-itheory computatfons. A comparison of the experimsn- tal and theoretical results for the wwept and the swept+aok plan forms of aspect ratios 3 and 4.5 bas been presented ip reference 4.

The coefficients and eymbols used throughout the repart are def fned ES follows:

.

mACA RM no. A M 2 1 3

8 A

b

C

- C

ce

H

h

L

2

M

9

R

s

se

v

aspect ratio ( SP/S 1 span of the model, feet

chord of the model, feet

*O

root-me-qusre elevator chord aft of .the hinge line measured pixallel t o the plsne of symmstry, feet

chord of the eleva-&or aft of the hfnge line maswed perpendicular to the hinge line, feet

hinge moment, foot-pounds

section hinge moment, faot-punds ,

lift, pounds

section lift, sounds

pitching mazqsnt about a lateral axis through the 0.25F point , f oo+pounds

first naomsnt of the elevator area sft of the hinge line about the hinge line, feet cubed

free-stream m c pressure (&v.) , pow per square foot

Reynolds number (pW/p)

axea of the elevator aft of the hinge line, square feet

velocity of air, feet per second

4 NACA RM No.

a corrected angle of attack, degrees

a0 corrected section angle of attack, degrees

6,

P abeolute viscosity, slugs per foot-rsecond

#

elemtor deflection (positive when trailing edge of elevator is down) lllsasured in a plane normal to the hinge line, degrees

P deneity-of air, slugs per cubic foot

Parameters

I

elevato-ffectivenss parameter

4

NACA RM No. A 8 J 2 l 5

The &wept horizontal t a i l model tested in this investigation had an aspect ra t io of 2 and a taper rat io ( ra t io of t i p chord t o root chord) of 0.5. The 0.7hhord line (elevator hinge line) was perpendicular t o the simulated plane of symmetry, result- in 13 16.7' angle of sweepback of the 0.25-chord line, as shown in figure 1.

The two4imensional model had a chord of 3.5 feet, and spumed the Tifoot dimension of the 7- by 1Mwt wind-tunnel t e s t section.

Both models were equipped with a sealed radiusinose O.3khord elevator. The airfoil section which was parallel t o the a i r stream was the same as for the models of references 1, 2, 3. The slight discrepancies between the model coordinates and the tnre NACA 64A010 coordinates (table I) are not considered important.

The gaps between the elevators and the shrouds and the gaps between the elevator noses and the balance plates (seal gap) are shown in figure 1. The elevator nose gaps were sealed over the complete span of both models. In addition, the elevator of the twdimensional model was sealed a t e i ther end and the elevator of the model of aspect ra t io 2 w a s sealed at the inboard end and at the outboard hinge bracket (8wercent span). The. inboard hinge bracket of the model of aspect ra t io 2 and the two hinge brackets of the twdimsnsional model were located outside of the air stream. Pressure orifices were located in the balance cha&ers enclosed by the shrouds both above and below the nose seal at several spanwise stations.

outboard of the hinge bracket. . The orifices at gl-percent span of the model of aspect ra t io 2 were

The t i p shape of the model of aspect r a t i o 2 was formed .by rotating the t ip airfoil section parallel to the .undisturbed a i r stream about a line inboard of the t ip, a distance equal t o ' the praxim t i p ordinate.

Photographs showing the models mounted in the wind tunnel are presented in figures 2.and 3.

TESTS

The tes t s were conducted in the Amss 7- by l M o o t w i n d tunnels. The model of aspect r a t i o 2 was mounted' on a turntable flush w i t h the floor (fig.2), an3 w a s tested with a dynamic pressure of 28 pounds

6 AACA RM No. A 8 J 2 1

per square foot, corresponding t o a Reynolds nmiber of 3.0 x 10 '. A limited tumunt of h t a was also Obtained a t R e y n o l d s numbers of 5.0 and 7.5 X lo8. he t w d i m S n s i o n a l model ( f i g . 3) w a s tested at m c -pressures of 22.5, 40, 57, and 75.5 pound^ per square foot1, resulting in Reynolds numbers of 3.0, 4.0, 4.8, and 5.5 x lo8. All tes t s were co-ucted with the models in the smooth condition with the elevator sealed unless otherwise speclfied. For those testa with leading-edge rougbnssa, standard ro~@ness was applied as defined in reference 5.

Model lift and pitching mmnt were meaeured by =ana of the wlnii-turmel balance system. Elevator hinge moments were measured by means of resistsnc&ype torsional strain gages. €Yeesures above and below the elevator nose seal in the balance chamber were m~asured by the use of a manamster connected t o the orifices Fn the elevator balance chaaiber.

All coefficients and the angle of attack have been corrected for the effects of the tunnel walls by the methods of referencee 6 and 7. The corrections listed below were added to the data:

where

hxor j e t - b o q correction t o angle of attack

4 2 stmamline-curvcbture correction to angle of attack

he sues ~f the d p a m ~ c pressure of 40, 57, and 75.3 pounds per square foot are the t e s t m c pressures corresponding t o a Reynolds nuniber of 3 .O x 10' f o r the models of references 1, 2, asd 3.

mcA RM No. mu 7

Ern, 4 c o ~ o t i o n t o pitch-nt coefficient

%, Ache correction t o hbgg-moment cdeff icient

R = u Y czu uncorreotsd lift; coefficient

unaarrected section pitch-nt ccref f i o i e n t

RESUlXS ABD DISCUSSIOX

The results of t e s t s of the d e l of aspect ratio 2 are presestea in figures 4 t o 9 and those for the two-dimensional model are presented in figure$ 10 ta 18.

The variati- of lift , -nt, and pit-nt coaf f i- cienta w i t h augle of attack are given in figure 4 for the model of aspect ra t io 2 and in f igq 10 for the tu-aeional model a t a Reynolds n m e r of 3 .O X 10 . H-nt cueif iciercts are ale0 shown as a. function of the elevator angle for various angles of attack in figures 5 and II. Additional data obtained for ghe two-dlmsnaiondl model at.Reynolds nunibers of 4.0, 4.8, and 5.5 X 10 are presented in figures 12, 13, and 14. 'phe variation of the pressure coeffi- cient acrosa the elevator nose seal w i t h angle of attack ia preagnted in figures 6 and 15. The effect8 of variations of the Reynold8 nuniber, standard lead-dge roughness, and removal of the elevstdr nose seal on the lift and hing-mnt coefficients are shown in figures 7 t o 9 for the model of aspect ra t io 2 and in figurea 16 t o 18 for the two-dimensianal model.

Effectiveness and Hinge-Xonnmt Pmmneters

The 1FfGeffectiveness and the hinge-mament p8ramsters are listed in table 11*. AB shown in the table, ch,: for the model of aspect ra t io 2 was -0.0002, and the sectlon was 4 . 0 0 5 ' 7 3 the value of % (-0.0072) for the d e l of aspect ra t io 2 was l i k e wise lower than the corresponding section c~~ (4.0ll4). The elewtorceffectivenese psrarrYstcr age was higher for the model of

-0

e

~~~~

2The parameters f o r the tw&imsnsianal model are'presented for R, 4.0 x lo6 in table 11. These values ure essentially the as those obtained at R,' 3.0 X lo6 fo r the model in the smooth condition w i t h the elevator sealed.

c

8 NACA I??; No. Am21

Stat ic Longitudinal Stabili ty

'Phe variation of pitching+mmnt o w f f i c i a t with angle of attaok (fig. 4( c ) ) indicates that the &el of aspect r s t i o 2 YBB stat ical ly unetable I ( ~ I C d d . t x ) , ~ , ' = 0.00233y measured through eero angle of attack, but that the static longitudinal stability increased a t the a t a l l , as would be predicted fromthe results of reference 8. The twe-dimens iaasl model was margimllg unstable [ ( d d d a o ) 8 e + = 0.00041 as shown in figure 10( c ) . No data were obtaineU for the tw&irnsnsianal model beyond the stall became

occurred a t t.he stall. the nsodel Was not d € ~ € i i ~ e d tQ W i t h s t a n d the 8ev8re buffet- which

Scale Effect

The effects of variatiom of the R e p l d s number are shown in figure 7 for the model of aepect ra t io 2 and in figure 16 f o r the twcmU.nn3nsional model. Data for he model of aspeot r a t i o 2 Were obtained for s Reynolds nuniber range from 3.0 t o 7.5 X 10 ', and the range for the twdimensidnal &el was from 3 .O t o 5.5 X 10 .

The lllaximum lift coefficieat of the model of aspect ra t io 2 increased slightly with increaaing Reynolds nuniber, but there was no change in the lift or h-nt parameters (memured through eero angle of attack).

A small increase in the l w u r v e slope ( A c z , = 0.002) was

mssured for the twdimsneional mdel a t the highest Reynolds number. The rate of change of -merit cwfficient w i t h angle of attack c h was comtant over the Reynolds nuniber range, but there was a small irregular variation in the rate of change of hinge-momsnt ' coefficient with elevator deflect Ian cue.

Effect of Stnnrlard Raughnees

XACA RM No. A M 2 1 9

Normally, the effect of standard roughness is t o increase the lift coefficient by an‘increase in the angle of s t a l l . Hawever, the angle of stall f o r the model of aspect r a t i o 2 was in i t ia l ly so large (low-aspect-dtio effect) that standard roughness was practically ineffective in increasing the angle of stall beyond that of the model in the smooth condition. For th i s reason, only nominsl Increases in the maximum l f f t coefficient were obtained.

The value of ch, was changed from 4.0002 t o 0.0006 by r o u g h ness, and %, xa8 changed from -0.0072 t o -0.0070. The elevatoz- effectiveness

standard effect on any t o -0. 0108a. measured.

+xmeter cr$, was uric-.

roughness on the tw&imensional model had no apmciable petrsmeter except cbe , which was changed from -0.0114 The effects an the lnaxiwun lift coefficient were not

Effect of Removing Elevstor Nose Seal

The ms j o r effect of reimving the elevator nose seal ( e e l s in smooth condition) was t o reduce the lif’t-effectlveness parameter czse of the two-db3nsional model. AB shown in table 11, cz6, was reduced from 0.065 t o 0.063 for the t w d i m n s i o n a l model, but w a s unchanged f o r the naodel of aspect ra t io 2. me 1ift-c- slope was unchanged for the model of aspect ra t io 29 but the mimum lift coefficient wgs reduced. (See fig. 9( a). ) !Phe lil3-curve slope of the twMimsnsional d e l was reduced from 0.108 t o 0.104. H‘!hg.ment parameters (measured through zero angle of attack and zero elevator defleotion) were relatively unaffected by remod of the seal for either model. However, for large elevator deflections the hinge moments were somwhat increased, as shown in figures g(b) ana 18(b).

CONCUJSIONS

The results of testa conducted t o evaluate the low-speed a e r e dynamic characteristics of an unswept horizontal t a i l model of aspect r a t i o 2 and a two-dimensional model having the same airfoil section indicate that:

3The values of the lift and h i n g e a m n t parameters presented in table I1 were derived from large-scale p lo t s of the data.

10 NACA RM No. A&

1. No significant acale effects were encoptered for either model for Reynolds numbers from 3 .O to 5.5 X 10 .

2. The effect of standard l e a d w a g e roughnees on the model of aspect ratio 2 was to change Q+,, from 4.0002 to 0.0006. The elevato-ffectivenese parameter was unchanged.

3. Removal of the elevator nose seal reduced the lift-effectiveness parameter cz8, from 0.065 to 0.063 for the two-dimsnsioaal model.

Amea Aeronautical Laboratory, ' National Advisory Committee for Aeromutics,

Moffett Field, Calif.

Conversion Factors for HFnge4oment Coefficients

Because several methods are in me for the conversion of hinge momnta to nondimsnsional coefficient form, factors relating the various msthods are presented. To obtain the hi-ment coeffi- cienta for one of the l i s t ed msthods, multiply the value of the hinge-moment coefficients of this report by the corresponding factor i n the following table: '

1 Aspect ratio 2 model Equations for hing-nt coefficients

Conversion fact or

1.000

9 983

983

Note: The factor for the t w & h n s i o n a l model is unity for all the equations.

mAcA RM Ho. A 8 J U 11

1. M s , Jules B., Jr.: WindJlhnnel Investigation of' Horizontal Tails. I - U1~8wep-b and 35O Ewept-Back- Plan Forms of Aspect Ratio 3. NACA RM No. A7K24, 1948.

2. Doda, Jules B. , Jr.: WinaJJhgnel lhveatigation of Horizontal Tails. LI - Urnwept azld 35 Sweptrsack Plas Forms of Aspect Ratio 4.5. NACA RM No. A8Bl1, 1948.

3. Dods, Jules B., Jr.: Wind4ungel Bvestigation of Horizontal Tails. III - Unsuept and 35 SweptrBack Plan Forms of Aspect Ratio 6. IXACA RM No. A8H30, 1948.

4. Jones, Arthur L., and Sluder, Lo=: An Application of Fallmer's Surface4oading Mathod t o Prediotions of H i n g e 4 b m e n t Faramters for Swept-3ack W a s . KA(2.A TN No. 1506, 1948.

5. Abbott, E-a H., von Doenhoff , Albert E., and Stivers, Louis S., Jr.: Summary of Airfoil. Eata. NACA ACR no. L%!05, 1945.

6. Swanson, Robert S . , and Tol l , Thomas A. : Jet+oundary Corrections for ReflectiowPlane Models in Rectaagulaz W i n d Tunnels. NACA Rep. No. 770, 1943.

7.. Allen, H. Julian, and Vincenti, Walter G. : W a l l Lnterference in a ~ ~ F m e n a i 0 1 1 a l 4 ' l o w Wind Tunnel With Consideration of the Effect of Compressibility. KACA Rep. No. 782, 1944.

8. Shortal, joseph A., and Maggin, Bernard: Effect of Sweepback and Aspect Ratio on Longitudinal Stability Characteristics of Wings at LQW Speeds. mACA Tm No. 1093, 1946.

12 NACA RM No. A m 1

TABLE I .- COo19D- FOR TBE NACA &A010 AIRFOIL AM) THE WDFU TESTED

[All Dimensions in Percent of W i n g Chord]

Upper asd Lower Surfaces

Stat ion

'0 .!x -75

1.25 2.50 5.00 7.50 10.00 15.00 20.00 25.00 30 .oo 35.00 40.00 45.00 50 .oo 55.00 60.00 65.00 70.00

80.00 85.00 90 .oo

75 -00

95 00 100 .oo

NACA &A010 ordinate.

c

0 .804 969

1.225 1.688 2.327 2.895 3 199 3 813 4.272 4.606 4.837 4.968 4.995 4.894 4.684 4.300 4.0U 3 597 3.=7 2.623 2.103 1.582 1.062 -541 .021

Model ardfnste

0 .81g 987

1.247 1.696 2 333 2.780 3.202 3.816 4.280 4.610 4.842 4.950 4 975

4.672 4.373 4 .OU 3d594 3 0131 2 637 2.120 1.595 1 . o n 553

0

4. sa9

LE. radius 0.68p T.E. radius 0.023&

%ame for botli the HACA 6 k A O l O section and the models.

EtACA RM No. Am21

I Paramter Model smooth; I elevator

sealed

Model Condition

Model with standard roughness; elevator

sealed -

Model smooth; elevator seal

removed.

I cha

Aspect ratio 2; R , 3.0 X 10'

-0.0002

-m72 .

.Ob0

.029

- 0 73

TwcAiimensioml; R, 4.0 X lo6

-0.0057

-. 0114

.lo8

.065

-. 60

4.0002

-. 0074

.040

.029

- 0 73

4.0057 4.0057

-.0108 -. 0112 .lo8 .lo4

4 -. 60 -. 60 -qpjg7

8

. . . . . .

-

Aspect mtio 2 Two-dimsnsiona/

fiper mtio a5 - Ele wtor area 3.025 #"? Z142 ft ' C 3.293ft 3.500fi

A M /OD83 ft ' 23,807ft'

5 02?0 ft 1.050 ft -

Drawing djmensions In inches

(6) Two-dimens/onal.

Figure 1.- Plan forms of the unswept hodzontal tail model of aspect mtio 2 and the tm-dlmemhnal moM.

G

. ..

?

. . . . . . . ..

(b) Three-quader r e a Hew.

Figure 3.- !Che two-dlnemional model mounted in t h e 7- by la-fwt wind tunnel.

. . . .. . . . . . .. . . . . .. .. " ' ' I

Fjgure 4.- Lift blnge-moment andpjfcbing-momenf coeffldents forthe model of ospeef rafio 2. R. 3 . 0 ~ 1 0 . 6

22 NACA RM Mo. A8J21

,%) Hhgs-moment coefficfant.

. . . . . .

f i g m 4.- Conchded.

24

-24 -20 46 -/2 -8 -4 0 4 8 E/eVUtOf d8f/@CtiOfl, 88 d8g . - . .....

f igure 5.- Variotion o f hinge-moment coefficient with elevator def/ection for vorious ong/es of uttock for the mode/ of ospect ratio 2. 6 3.0 x 106:

RACA RM no. A8J21 25

6

$ % cr,

LO

.8

.6 r

4

.2

0

4

.2

0

72

4

.2

0

:2

-I

- . 6 ~ " " " ~ " ' " " ' i " ' ' ' -4 0 4 8 12 16 20 24 28 32 L ~ , ~ A ~ A /

%**/

Angle of aftack, (I, deg

(0) 8, = 6: O,*- 4:

Figure 6.- Variation of pressure coefficient across e/evotor nose sea/ w angle of attack for the mode/ of aspect rotio 2. R, 3.0 x /Ob:

Vfb

26 NACA RM No. A m 1

. ..

"-

.. , -

NACA RM No. A-1

(01 Lift coeff.c/enf.

Figure Z- Comparison of fhe /iff and hinge-momenf coefficients for various va/ues of the Reyno/ds number f o r fhe mode/ of aspect ratio 2.

28 NACA RM No. Am21

.24

.20

. /6

. /2

& -08 4. C

. 0 4 g % 8 0

E e -.04 8 , & -.08

-. /2

-%

0

$

-. /6

-20

-.24.

-4 0 4 8 /2 1 6 20 24 28 32 Angle O f aftock, deg "537

(&,I Hingemoment coefficient

Figure z- Concluded.

NACA RM No. Am21 29

116

1.4

.8

O" .6

7 2

-4

-.6

-.8

-110

Angle of attack, Q, deg =-z57

f a / Lift coefficient.

Figure 8.- Compurison of the /iff and hinge-moment coefficients for the mode/.of aspect rutio 2 with andwithout /euding-edge roughness, RJ 3.0 x IO'.

-

30 NACA RM No. A-1

. 2 0

. /6

. /2

08

. 0 4

0

- .04

-. 08

-. /2

-. /6

720

-24

~ 2 8 I l l l l l l l l l l l l l t l l l l I

-4 0 4 8 /P 16 PO 24 28 32 Ang/e of attack, 0, deg v

fb) Hingmoment coefficient.

Figure 8.- Concluded.

EACA RM No. Am21

2 E Q, .6

4

0

-A

-.6

-8 -4 0 4 8 /2 / 6 20 24 28 32 Angle of oftack, a, deg

=-Ev

(0) Lift coef ficienf.

F igure 9.- Comparison o f fhe /iff ond hinge-moment coef- f icients for fhe mode/ of uspect ra t io 2, wifh and wifhouf elevafor sea/. e 3 . 0 x / 0 6

32 NACA RM No. A8J21

.20

. /6

. /2

.OB

e-

'(z -.04

B F -.08 9, I h

8 0

$ -./2

-. 16

-. 20

-.24

-4 0 4 8 12 1 6 20 24 28 32 Ang/e of attack, a, deg

" .- . . . -.-

(b) Hingemoment coeffkient.

figure 9- Conc/.ded.

NACA RM No. A8321 33

1. 0

.8

.6

Q" . 4

-. 6

-. 8

-/.O

"1.2

-/. 4

F i g u r e 10.- Secfion / iff8 hinge-moment, and.pifching-momenf coeff icienfs of the NACA 64A0/0 uirfoi/. 4 3 0 x / O 6

34 RACA FM no. A8J21

c

Section angle of attock,a,, deg -5%7

(b/ Hinge-moment coefficient.

35

.24

.20

. /6

. /2

.08

.04

0

-.04

-. /2 0 4

Section m g / s of

b 6 6 4 d 2 0 0 a - 2 0 - 4

0 - 9

v - / 5

A - 6

D - / /

8 /2 /6 24 ottuck,a*, deg

(e) Pitching-moment coe f ficien t.

Figure 10. -Conc/uded.

36 mAcA EM No. A-1

.36

.32

.28

.24

8 " .20 a?

C

. / 6 B 0 c,

-.04

0.08

-. /2

-. /6

E/evator def/ecf/on Se , deg =ZP-

Figure /I.- Variation of section hinge-moment coefficient with elevator deflection for various ongles of attack o f the NACA 6 4 A 0 / 0 uirfoil. R, 3.0~106

MclCA RM No. Am21 * 37

1. 2

1. 0

.8

.6

-. 6

-. 8

. -1.0

-1.2

-1.4 -12 -8 -4 0 4 8 12 /6 20 24

Section angle o f ottock,cr,, deg = - 3 7 *

(a/ Lift coefficient.

Figure /Z.- Section lift, hinge-momenf, and pifching-momsnf coefficienfs o f the NACA 64A0/0 akfoi/. 4 4.0 x/O6

Section angle of aftack, cr,, deg

{b) Hinge -moment coefficient.

IUCA RM No. A8J21 39

.20

. I6

./2

.08

.04

0

=* 8 -.04

3 -% Q

0.08

-. /2

(‘c) Pitching-moment coefficient.

figure 12.- Conc/uded.

40 RAGA RM Mo. A0J21

Section ongh of otfock,ao, deg ===a37

(a/ Lift coefficient.

Figure 13: Section lift, hinge-moment ond pitching-moment coeff ic ients of the N A C A 6 4 A O l 0 a i r f o i l . e 4.8 x t 0 6 .

NACA RM No. A8J21

A 6 6 4 d 2 0 0 u - 2 0 - 4 A - 6 v - 9 D - / / v - / 5 v - /7

I t

12 16 2 Section angle of a t t o c k , ~ ~ , deg -

fb/ Hinge-momen f coefficient. ,

Figure f3.- Con finued.

42 NACA RM no. A m 1

.20

4

.04

I cn

-04 c,

Q -\

-. 16 -8 - 4 0 4 8

6 6 4 d 2 0 0 - 2

0 - 4 A - 6

v -15 P - / 7

D 3

Section mg/e of otfack,ao, deg

"7 [c) Pitching-moment coefficien f.

i

RACA FM No. A-1 43

1. 2

1. 0

.8

.6

Q- . 4

-2 -%

4

C

.2 0 0 Q O

Q -2

8 -.4

%

Q

-. 6

-. 8

4-0

-/.2

Section angle of affack,aor deg "237

(a) Lift coefficient.

Fiqure 14.- Section hft hinge-moment and pitching-moment coefficients of fhe NACA 6 4 A 0 / 0 airfoiL 4 55xI06

. _

- - KACA RM No. A8J21 45

-20

1 6

s 12

-08

.04

0

0.04

-.08

-8 - 4 0 4 8 12 Section ungle of uttuck,ao, deg

(c) Pitching-moment coefficient.

figure 14.- Conc/uded.

46 NACA RM No. Am21

Section ung/e o f uttuck, a,, deg "

Figure 15.- Vuriution of pressure coefficient across e/evafor nose s e d with ung/e of attack of the NACA 6 4 A 0 / 0 uir foil 6 4.0 x /06

NACA FM No. Am21

0

-.6 0 Y

C

-/.6

-/.8

-20

./2 -8 - 4 0 4 8 /2 /6 20 24 28 32 Section angle o f uftack,a,, deg

T

Figure 15- Conchdea!

48 WCA RM No. Am21

Section ong/e of uffock,ao, deg v tu) Lift coeff/c/ent.

Figure 16.- Comparison of fhe section /iff und hinge- moment coefficients o f the NACA 6 4 A 0 / 0 oirfoi/ ut various Reyno1ds numbers.

IPACA RM No. A-1 49

Section ung/e of uftuck,ao, deg "

fb) Hingemoment coeff/cient.

,Figure /6.-Conc/uded. .

NACA RM No. A-1

1.2

.8

3 -.z C

CI

G -. 4

-. 6

-. 8

-/ .O

4.2

4 . 4 -8 - 4 0 4 8 /2 /6 20 24

Section ongh uf ottock,%, deg v (a) Lift coefficient.

Figure /Z- Compurison of the section /if/ ond hinge-momenf coefficients of the NACA 6 4 A 0 / 0 uirfoi/ with andwithout /eacting-edge roughness. R, 4. OIX lo6.

NACA RM No. A8J21

.28

.24

-k

.08

-.08

-. I2

.8

.6

.2 e -2 s o Q,

8

-.8

Figure 18.- Comparison of the section lift und binge-moment coefficients of the NACA 64A0/0 d f f o i / with and without elevator sea/. R,. 4. o x 106

. MCA RM No. A8J21 53

.28

.24

.20 8

\ 8 .08

$ -.04

9.08

-. /2

Unsealed

-8 - 4 0 4 8 12 16 20 Section ungh o f attack,^^, deg

v (b) Hingemoment coefficienf.

Figure 18. - Concluded.

. ..

. .

4 ._.

1