_: "'-_ _ "ll_" .:_ _-_

NATIONAL ADVISO Y-- -MITT E

FOR AERDN UTIL'S

REPORT No. 610

IN

OF RELATED FOR_ARD-CAMBER AIRFOILS

THE VARIABLE-DES;SITY WIND TUNNEL

By EASTMAN N, JACOBS, ROBERT M. PINKERTON

• ln A R • : N

E

REPRINT OF REPORT No. G10. ORIGINALLY PUBLISHED NOVEMBE_

l

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l

• -_ iJ ,

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1939 == '} , _i: ll

NATIONAL TECHNICALINFORMATION SERVICE :_

U.S. DEPARTMENTOFCOMMERCE

SPRINGFIELD,VA. Z216! _ :_-;-_._Jl

!?_ S,_ Area, of wing

b Spanc Chord

b_A Aspect ratio, _ _

.... £, Angle _°f_ stabilizer setting (relative_____to thrust.:- --:-._ --"1........ line.)_"-:- - -- - ._

O Resultant moment

.... _q -Resultant ang_ar velocityVI 7-.'--- -_ . -

R Reynolds number, p where Sis alinear dimen- ::

N 0 T I C E

THIS DOCUMENT HAS BEEN REPRODUCED FROM

THE BEST COPY FURNISHED US BY THE SPONSOR-

ING AGENCY. ALTHOUGH IT IS RECOGNIZED

THAT CERTAIN PORTIONS ARE ILLEGIBLE, IT

MA K-

AS

IS BEING RELEASED IN THE INTEREST OF

ING AVAILABLE AS MUCH INFORMATION

POSSIBLE.

:T

REPORT No. 610

TESTS OF RELATED FORWARD-CAMBER AIRFOILS

IN THE VARIABLE.DENSITY WIND TUNNEL

By EASTMAN N. JACOBS, ROBERT M. PINKERTON.

and HARRY GREENBERG

Langley Memorial Aeronautical Laboratory

REPRINT OF REPORT No. 610, OB!GiNALLY PUBLISHED NOVEMBER 1937

i-b

r 7

NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

HEADQUARTERS. NAVY BUILDING, WASHINGTON. D. C.

LABORATORIES. LANGLEY FIELD. VA.

Created by act of Congress approved March 3, 1915, for the supervision and direction of th$ scientific study of the problems offlight (U. S. Code, Title 50, Sec. 15i). Its membership was increased to 15 by act approved March 2, 1929. The members areappointed by the President, and serve as such without compensation.

JOSEPH S. AMES, Ph. D., Chairman,

Baltimore, Md.

V^NNEVAR BUSH, Sc. Dr, Vice Chairman,

Washington, D. C.

CHARLES G. ABBOT, Sc. D.,

Secretary, Smithsonian Institution.

HEsav H. AR_:OLD, Major General, United States Army,

Chief of Air Corps, War Department.

GEoaas H. B_ErT, Brigadier Genera], United States Army,Chief Matdriel Division, Air Corps, Wright Field, Dayton,

Ohio.

Lr._._ J. Bazacs, Ph.D.,Director, National Bureau of Standards.

CLINTON M. HESTER, A. B., LL. B.,

Administrator, Civil Aeronautics Authority,

ROBERT H. HINCKLEY, A. B.,

Chairman, CivilAeronautics Authority.JEROME C. HUNSAKER, SC. D.,

Cambridge, Mass.SYnNEY M. KRAUS, Captain, United States Navy,

Bureau of Aeronautics, Navy Department.

CHARLES A. LINEnERGH, LL.D.,

New York City.

FRANCIS W. REICHELDERFER, A, B.,

Chief, Upited States Weather Bureau.

JOHN H. TOWERS, Rear Admiral, United States Navy,

Chief, Bureau of Aeronautics, Navy Department.EDWARD WARNER, SC. D.,

Greenwich, Conn.ORVILLE WRIGHT, Se. V.,

Dayton, Ohio.

GEORGE W. LEWIS, Director of Aeronautical Research

Joan F. VIcI'oRY, Secretary

HENRY J. E. REID, Engineer-_n-Charge, Langley Memorial Aeronautical Laboratory, Langley Field, Va.

JOHN J. lEE, Technical Assistant in Europe, Paris, Francs

TECHNICAL COMMITTEES

AERODYNAMICS AIRCRAFT STRUCTURES

POWER PLANTS FOR AIRCRAIrr AIRCRAFT ACCIDENTS

AIRCRAFT MATERIALS INVENTIONS AND DESIGNS

Coordination of Research Needs of Military and Civil Aviation

Preparalion of Research Programs

Allocation of Problems

Prevention of Duplication

Consideration of Inventions

LANGLEY MEMORIAL AERONAUTICAL LABORATORY

LANGLEY FIELD. VA.

Unified conduct, for all agencies, of scientific research on thefundamental problems of flight.

OFFICE OF AERONAUTICAL INTELLIGENCE

WASHINGTON. ]D. Co

Collection, classification, compilation, and dissemination ofscientific and technical information on aeronautics.

REPORT No. 610

TESTS OF RELATED FORWARD-CAMBER AIRFOILS IN THE VARIABLE-DENSITYWIND TUNNEL

By EASTMAN N. JACOBS, ROBERT M. PINKEBTON, and HARRY GBEENBEaC

SUMMARY

A recent investigation of numerous related airfoils

indicated that positions of camber forward of the usual

location resulted in an increase of the maximum llft. As

an extension of this investigation, a series of forward-

camber airfoils has been developed, the members of which

show airfoil characteristics superior to those of the airfoils

predously investigated.

The primary object of the report is to present fully

corrected results for airfoils in th_ useful range o.f shapes.

With the data thus made available, an airplane designer

may intelligently choose the best possible airfoil-sectlon

shape for a given application and may predict to a reason-

able degree the aerodynamic characteristics to be expectedin flight from the section shape chosen.

For airfoils of moderate thickness, the optimum camber

position was Jound to correspond to that of the N. A. C. A.

23012 section. A discussion is included concerning the

choice of the best thickness and camber for full-scale

applications depending on specific design conditions.

Data to assist in the choice of the optimum section for a

design using split flaps were obtained by testing some of

the better sections with trailing-edge split flaps.

INTRODUCTION

The well-known airfoil-section investigations in the

N. A. C. A. variable-density wind tunnel have beendirected toward studies of the effects of variations of

airfoil-section shape. Such studies are intended to

determine the range within which the best possible

section shapes for any given application will generally

be found. With the data thus made available, anairplane designer may intelligently choose ttle best

possible airfoil-section shape for a given application

and may predict to a reasonable degree the aerodynamiccharacteristics to be expected in flight from the section

shape chosen.

The first investigation of this series (reference 1)

gave comparable data from the standard large Rey-

holds Number tests in the variable-density tunnel,

which were considered as representative within the

flight range, for related airfoils covering section-shape

variations in the neighborhood of commonly used

airfoils. A subsequent investigation (references 2 and

3), covered by this report, deals with airfoil sectionsdiffering from those commonly used in that the camber

occurs farther forward, i. e., nearer the leading edge.

The desirability of this shape characteristic was indi-cated by the first investigation.

After the mean-line shape designated 230 had been

found to be near the optimum (reference 2), an airfoil

having the N. A. C. A. 23012 section was tested in the

N. A. C. A. full-scale tunnel to verify the superiority

of its characteristics over those of commonly used air-foils (reference 4). This and other tests (references 5

and 6) in the full-scale tunnel also provided valuabledata on which to base an interpretation of the variable-

density-tunnel data as applied to flight. In addition,

a selected group of the related airfoils has been tested

over a wide rahge of values of the Reynolds Number.

The results of this investigatior. (reference 6) provided

the information needed to apply the standard variable-

density-tunnel airfoil data to flight at any particular

value of the flight Reynolds Number.

Aside from the presentation of the important section

characteristics fully corrected for application to flight

at the standard value of the Reynolds Number

(effective Reynolds Number approximately 8,000,000)

for all the forward-camber series of airfoils tested, one

object of the present report is to consider possible ira.

provements of the N. A. C. A. 23012 section. This

possibility was investigated by an analysis of test

results for a number of airfoils, the shape of which

varied systematically from the N. A. C. A. 23012.Finally, several airfoils within the most useful range of

shapes were investigated to provide data for the various •

airfoils that may be chosen as most efficient in par-

ticular applications.

l

C_

f

2 REPORT NO. 610--NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

The airfoils developed in the variable-density-tunnel

investigations have been designated by numbers baying

four or more digits. As explained in reference l, ttlemaximum ordinate of the mean line is called the

"camber" trod the position of tile maximum ordinate

is Called the "position of th_ camber." The airfoils

reported in reference l were design.ated by a number

having four digits. The first digit indicated the camber

in percent of chord; the second, the shape of the meanline as indicated by the position of the camber in

tentl_s of the chord from the leading edge; and the last

two, the maximum thickness in percent of tile chord.

The extension of the investigation to the forward-

camber airfoils presented herein (including the airfoilsin references 2 and 3) necessitated an extension of the

designation numbers to cover the new mean-lineshapes. As before, the first digit indicates the relative

magnitude of the camber; but the second has been re-

placed by a pair of digits, which together indicate themean-line shape for which position of camber is one of

the parameters; and the last two, as before, indicatethe thickness of the airfoil section. The camber, the

mean-line shape designation, the corresponding values

of camber, and the position of camber for these forward-

camlet airfoils are given in the following table.

"\. Mean-line shape designation

: \ (second and third digits)

Camber\

dos!g- ",, Position of caznbe¢,

\

[ (Actual camber in percent of

chord)

3 .................................... [ _ _ [ 2.3[ 2.8 a.| [ ....4 ............................ [ .... I 3.1l 3.71 4.21---

The table thus indicates, for example, that the N. A.

C. A. 230 - - airfoil has the camber 1.8 percent of the

_hord at 0.15c behind the leading edge.

The airfoils designated by both the four and the

five digit numbers have only one form of thicknessvariation. Changes in the form of the thickness va-

riation made by altering the leading-edge radius and the= position of maximu/il thickness (see reference 7) have

been designated by appending two additional digits

: separated by a dash from the basic airfoil designation.The first of these two digits indicates the relative magni-

tude of the leading-edge radius and the second indicates

the position of the max-imum thickness in tenths of

the chord from the leading edge. The significance of

the leading-edge radius designation is given below:

0 designates sharp leading edge.

3 designates one-fourth normal leading-edgeradius.

6 designates normal leading-edge radius.

9 designates three or more times normal leading-

edge radius.

The complete system of airfoil designation is illus-trated by the following examples: The N. A. C. A. 2212

(reference 1) has a camber of 2 percent of the chord

at 0.2 of the chord from the leading edge and a thickness

of 12 percent of tile chord. The N. A. C. A. 0012

(reference 1) is a symmetrical airfoil having a thickness

of 12 percent of the chord. The N. A. C. A. 24012

(reference 2) has a camber of approximately 2 percent

of the chord (actually 2.1 of the chord, see table I)

at 0,2 of tile cord from the leading edge and a thicknes_

of 12 percent of the chord. It will be noted that theN. A. C. A. 2212 and the N. A. C. A. 24012 have prac-

tically the same camber, camber position, and thickness;

however, the shapes of the mean-camber lines, desig-

nated by the digit 2 _n one case and 40 in the other, areentirely different. Finally the N. A. C. A. 0012-64

is a symmetrical airfoil having a normal leading-edgeradius and the maximum thickness at 0.4 of the chord

from the leading edge. The N. A. C. A. 24012-33 hasthe same mean line and thickness as the N. A. C. A.

24012 but has a leading-edge radius one-fourth thenormal and the maximum thickness at 0.3 of the chord

from the leading edge.The scope of the present investigation is best indi-

cated by figure 1, which gives the profiles of the air-

foils tested. Of the airfoils of 12 percent thickness

there are included a group of increasing camber: 00,

230, 330, 430, and 630; a group of varyirig camber posi-

tion: 210, 220, 230, 240, and 250; and some variations

of camber position for airfoils more highly camberedthan the 230 series. From the results of these tests,

the camber position corresponding to the series 230,430, and 630 appeared to be best, so that in most casesvariations of section thickness are included only for

these mean-line shapes and for the symmetrical airfoils.

Some variations of thickness distribution are included,

and also some of the more interesting airfoils with a

hlgh-llft device colasisting of a 20-percent-chord full-

span split flap.

TESTS OF REI,ATED FORWARD-CAMBER-AIRFOILS IN THE VARIABLE-DENSITY WIND TUNNEL3

_. _ _ ...._ ------

0006 =33006

0009"

0012

0015

0016

0021

21012

22012

83012

24012

Z5012

23009 _ 43009=

_3012 430] 2

230]5 43015

23010

_3021

43018

43021

32012

33012

34012

0012-63

0012-64

42012

: 43012

_ 4401_

23012-34

23012-64

430] 2-A

0018 - _-_*

_3009 °

63009 _jT_O

FloOgl l.--kirfoil proflle_.

63009

63012

63015

63018

8302]

_021

63021

64021

-_L. .... :i_=_-_', :i_̧

...... REPORT NO. 610--NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

DESCRIPTION OF AIRFOILS

The thickness variations of the airfoils are given in

references 1 and 7. The cambered airfoils have mean

lines of the form given in reference 2. Profiles of all

the airfoils presented herein are shown in figure 1.The models are of 5-inch chord and 30-inch span, of

rectangular plan form, and are constructed of duralumin

as explained in reference 8.

APPARATUS AND METHOD

The variable-density wind tunnel, in which the tests

were made, is described in reference 8: Routine meas-urements of the lift, drag, and pitching moment were

made at an effective Reynolds Number of approxi-

5ta t./p_ L'vo o

Z_ 095 -_2Z.5 1.31 . L V

5.0 /.78 :_7.5 2.10 , uI0 _ 34 -2, 4I_ _R7 2. 7

3.oo.. v40 2.90 : -2. _95O Z.65 2 560 2.28 .,2. 870 1.83 ./. L_80 1.3/ .I. 't90 .72 . . ',_

L 95 .40 - . '00 I00 (06) '-.d _)

I00 0 0,,. TTg-_--2:.o%_-

and to the "blocking effect" of the model in the tunnel.These errors have since been investigated (see the

appendix of reference 6) and have been eliminated by

correcting the manometer settings used in fixing the

tunnel air speed. Other errors mentioned in reference1 have been somewhat reduced.

RESULTS

The data are presented (figs. 2 to 51) in a manner

that is a slight modification of the standard graphic

form used in previous reports. The left-hand portion

of the plot presents the test data in the usual standard

form for rectangular airfoils of aspect ratio 6. In-

cluded also are the airfoil profile, the table of ordinates,

_ _ ,o 026

i-'o 0240 _o 40 60 80 IOO

PercenlotrcJ_ol'd I .022

- )_._ -] -_--_ .azo" _--J M .44 .018

i ii - ,.8 .3e 8.olz.... ktJ _____

I ==

71"

g!,--2N. :

..... i :it :T[

¸¸...........!.....t

i i I

I iI!l I /

-i--l--

i

. . i --_+.-

..... i.__4__-

5g

48

44

4oL

3z _

zo_k

_ Ht-i-_, _<rol- t--I t

! I

" " a

_#F-

tV

..._.Om

_, _ o/.o,_t.20 o _..00_

6 u, 12 .002

.4 "_.08 0

.g .04 _ ":l

0 _-.2u

.-.3E

_-.4

. 0A_rfo;/:_.a.c.a. ooo6 _.N.:3,Zm,O00 lSize: 5"x30" Ve/.ff_./_ec.):S#.bJ- 2Pres.fst_d.o_m,):gO.8 t_e: /-4-3Rl "Where fexfed:L.M.A.L. Tesf: V._T. 7441Cor_, ecPed for fvn_eLwall effecf ] "_

J l ...... !_. zo °...... 4----.

- _+-- /6

" '- 1- Xo I /2_"

__ 8 _

.-.)V,• :q- o,

[ ] 0007c ahead oFC/4 LO_c a6ovo ct, ord .... :- _

i _-L_- '_" J-d-8A;fFo;/: N.A.C.A. 0006 R.N._F_: 8,470,O00 l

O0_: I-4-3Z Teal: V.D.T. 744J_16

"8 "-4 0 # 8 /2 16 ZO 24

= ; := Angle oF o?foch; u (degrees)

28 3g v4 -.Z

FIGVRZ 2.--N. A. C. A. 0006 airfoil.

mately 8,000,000 (tank pressure 20 atmospheres). In

addition, for most of the airfoils, measurements of lift

in the neighborhood of maximum lift were made at an

effective Reynolds Number of approximately 3,800,000,

obtained by running at reduced speed with a tank

pressure of 20 atmospheres.The discussion of precision in reference 1 poinL_ out

certain errors in the velocity measurements due to a

change in the apparent density of the manometer fluid

with a change in the tank pressure from atmospheric

0 ._ .4 .6 .8 LO /g L4 16 L8

L/H coeff;cienf, c,=

and a portion of the lift curve in the neighborhood of

maximum lift obtained at a reduced Reynolds Num-

ber. The right-hand portion of the plot presents thesection characteristics derived from the experimental

data and fully corrected for turbulence and tip effects,

as explained in reference 6.In addition to the graphic form of presentation, the

most important characteristics, fully corrected, are

presented for each section in table I. The three columnson classification are explained in references 6 and 9.

TESTS OF RELATEDFORWARD-CAMBER AIRFOILS IN THE VARIABLE-DENSITY WIND TUNNEL5

TesP: V.D.T.1136 -16

E-.4 ._ Correc/ed lO ;f)f_l/e ospecf FO_I'O

-4 0 4 8 /2 t6 20 24 Z8 3Z T4 -_., 0 .Z .4 .6 .8 1.0 /.2 /1.4 /.6 1.8Angle of Q/lock, (X (degreeS_ c,.L/f!coeff/c;ent,

FIGURE4.--N.A.C.A.O01_#drloB.

J -8)0 )e _ l

above chord T

Airfo#," N.A,C,A. O01.Z R.N._ff_: 8,370,O00

D_te. 3-9 -35 Test: V ft. T.IZ3 7 -16

6 REPORT NO. 610_NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

"P?F"_I24 '51 -i 16:Eo 3_ 6_

• :n _I-.5: '/I -_ 4. Percent of chordi _o s.:gj-._,

3oi6._oI-_o ----,

_0 5:/ -54, ---- -+-+_o 4.;el-4 75 __ -- . _ __I 7013_/j-3aj 4-1_ L L/ 80] 2.; 21-2 7,_ +_ ....

t. 1 95 _/|- 8J - - rpool:._:,!{-/,_

v :°V_Aio ! )_, tL.E.Rod.:/.58

o..,o712

.'o_.ol-{-i_F,:- o})

'_ ,2_ 8oLl_J.l1J

} ?,oo :i,

q,

-8

o 20 40 60 80 /00

iZ8 _ 6

24 t 26

zo_ 40

I_ '% eo

• O o I00

0 t_ "t

_ oa I

Pr e s. (sf"nd._lm.)."ZO.3 Do#e: 7-5-3#IWhere tesfed:L.MA.L.Te_:V.D.T.I/d_Corrected {Or fur_net-woH efltecf -.4

Angle oF offock, W (degrees)

.026

+OZ4 T

.OZZ j

.O20

•44 .018

<tz.o .40 ,,g.Oi6

L8 .36 _.014

1"6"3Z_'otz_r_'._ ._ }OlO_._._ _o_ F_,_.o_._o_eoo_L

._ ,e_ .oo4_,6 u .12 .002 +-

.4 _ .08 0 _"

o o -.z

_ -,3

=4 =Z

FIGUR_ 5.--N, A. C, A. 0012-63 airfoil.

sto.._p_::.:,.._--_0 , -- - ,

2.5' ?.4.r ._¢5' t._ i , I5_ YZ' 3._ _o -'0 i i - .024v-

/0 I ¢'2l if' '_ "4 0 20 40 60 80 / l 0

__1 ....... _f. _._. " i ®

] 75"90 t ?00- ' w D,

_-lTjlJ_]_._-_/_f .LCI_.-I ,o'_"_o}_'°oo,t-

:If l-i -='__@__, __"r_Tlii !,-T-r-_ o o i-#--_ i _IA,i(o,l. _A•C.A.OOIZ-64.RI_:301(_O001 o L

_! lA ]si,e:s"xao" VeZr_.l_;_.):70.ZJ__ ? __[_ I JPres.(st'nc_olm.):ZO.8 Det_..7-7-34 [ " _ ""l

rl'r T ]Where #ested.L IdA L Test" V.O._//50 t _ r_J/ { _ _ Correc#ed for furlnel-wo// effect. _- 4 _ -'4 _

I__-4 0 4 8 IZ /6 20 24 28 3Z _6

Amgle Of offock, _ (degrees)

F-- ----

-i

' 14-2

FIGURE 6,--N, Ar C. A. 0_1_'_ airf_il.

! i

" - i 5ZL tl, 1,,

A/rfoi/ N.A C A 0012 64[ Tes i V.O TIL_O _

Oo:e.7- 7-a4 (#ff.) R._...zssaooo] /,_Correcled #o �mr#nile ospecf re#/o - _

0 ,2 .4 .6 ._ I0 IZ 14 Z6

L/:# coeff_c:en#, qo

--7

TESTS OF RELATED FORWARD-CAMBER AIRFOILS IN THE VARIABLE-DENSITY WIND TUNNEL

b

O

28_

24 _ 26

lasso

2,2_oo02,00

_-" _

_ o._.

-4_-8

o

Dt,.0

"b

28 _ 6

24t zb

_ ,s_e4oot

_o__4 "_.

-8

[2 -4

o 20 40 60 100Percen f of chord

.026

.024 #8

.022 44

F]oua_ 7.--N. A. C. A. 0012-6_ airfoil.

'7 3 t(

_ _ o 20 40 _o 8o_18 6_[ Percent of chord

7 _/71

,r3 750[++__; __[7,#31 J_ L/ I,'o 7-; '5 7 ?51 t

'" +"+_-- F l 7--:ol 57ot _

'.81 <s81 I t[_ "_-

#./I LY/L._L_,+'/ /._Vl I',P) '. , 6)1---_- . .

' I, _ __ __._

-! i_ _ _',_./t)LO0:4[ ,_rc,o + ,+- -

__. S/ze: 5"x30" Ve/.(ff/sec.]: 68,9 -.2_ PFes.(sl'_d, olrn_:ZO.O Dole:5-/7-34

Wh_re _esIed: L.M.A.L. Test: V.O.T.I/35- -- Corre C _'_ d for fun/",_ I-woH e ffec f -. 4

0 4 8 12 /6 20 24 2,9 32

Angle of o/lock. _ (degree_)

710339 0 - 46 - 2

:026 52.024 48_0

.022 44

.020 40

•44 .018 36

z.o .4o "_-o_e 32"_ ,o"

1.8 .36 _.014 28

1.6 .32 _.012 _"

¢ z4,.4 .z8_"_ _.._ .010 20 o

1.2_ 16_

/.o_ /2 ._-k

•a{o_ _ .004 8_

.12 .002 4.60

.4 ''+.o8 o O_

+2 .04 J -. i

0 0 "_ -.2 -8

-_ -.3 -/z

Dote: S-17-34 Test: V.D.T.I/3S -t6-.4 Correcfed to /mr/nile

-:4 ":2 0 .2 .4 .6 .8 10 i..2 14 16 1.8

L,"F/ coeff/cien_, c_

Flaultl 8.--N, A. C, A. 0015 airfoil.

+7

f

//

= ?= _== ;=8 REPORT NO. 61D--NATIONAL ADVISORY.COMMITTEE FOR AERONAUTICS

Fzou_z9,--N.A,C, A.0018airfoil.

i

o

........... _ .... 4 _

.o4_ obore, : _,_ ] L ! t iJ

Do/e'8.8-_# Tesl V_ _llGl ! t

.2 .4 .B .8 /0 /2 1.4 z8 18L/f/ coefh'cient, C,o

Fmu_¢ IO.--N. A. C. A. 0021 airfoil,

52it -i-- i

48

.4 .6 .8 /.0Lift coeff;cien_, r=,

L.

TESTS OF RELATED FORWARD-CAMBER AIRFOILS IN THE VARIABLE-DENSITY WIND TUNNEL 0

.026

.024

.O2O

FIGURE ll.--N, k. C. A. 21012 airfoil.

£

B _c •o 20 40 _9 80 I00

Percent o ¢ chord

ep,

p,

,;,'---J 0

A/rfo/l: N.A.C.A.2_OI2 R.N.: 3.I50.O00

Size: 5"x30" Vel(ff./sec.): 69.1 . -._

Pres.(slhd.ohn):20.6 Dote: 4-23-34

FIGURE 12,--N. A. C. A. 22012 _tirfoil,

52

44

3z

A/_-fo#.'NA.C.A.ZZOIZ R.N.

Dote: 4-Z3-3d Test: V.D. T, IIZ5 -18C__o_re cfed fo ,'mF//nite_spec t rOf,b

0 .2 ,4 .6 .8 ZO /E' t4 16 L8

Z /ft coeff,'c;enf, C .

I0 REPORT NO. 610--NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

04:tJ

O

28 _ 0b

Z4 } 20

_gO_ 40_q o

,e eoi

_o_e<

-8

_J, - f.

Z5J [E _ • ._O/#i :0; • ._3IS1 r,5_ -._3;0] _.6,! -I. I0

J ; . _6

3hi {5) "1.17

--_. _) ?0 [O.'C. ' [- --I -

_o - .o,°,O ii:I __o 2o 40 8o 8o IOO

Percent of chord .OZ2 --

- -- .OZO --_:

L _ .44 .018 ....

I

_g_[ 0_) (-._eI-- -i .... J --t-- --F---- _ --

S/o#e of rod,us/- -- _-" -" - -- / • --

,%o_o,__! i- _ i-b -_- ,_ _2° 8o,_-

.... ir T_-___-_--,_LT,I_-7-- - -_---i_.c_j- _. _.uu,_ -

-- ti f --Nt- 4--4"- -_ ._. _, '-

-Z_i_ , _--Y - ,H o o '...:-el_--__ __! A,'r/oi/:_A.C.A.23006 t{N..:3,140,000] _ " I-_ /__ . S/ze: g'x30" VeZff/./sec.): ¢a.e__ z _ - 31-

Pre$.(st'nd, otn_):ZO,7 Do/e: Z-12-351 " _ " I..... Where teste_ L.M.A,L, Tesf: V.O.E N>291 e I--

.... Corrected for funnet-wo// effect ]-.4 _ -.4 I-

Dote: 2-/_-35, Test: V.D.T,/zzgj 16

-8 -4 0 4 8 12 16 20 24 28 32 _4 -.2 0 .2 .4 .6 .8 10 tZ L4 16 L8

Angle of ot/ock, (_ (degrees) Lift coefficient, e,,

FLOURS 13.--N. A, C. A, 2_0/)6 airfoil.

...... . .'2 .

"-" £_

TESTS OF RELATED FORWARD-CAMBER AIRFOILS IN THE VARIABLE-DENSITY WIND TUNNEL 11

FzGu_ 1 IS.--N. A. C, A. _3012 airfoil.

.OZ4

/00 .OZZ

-/Z

Oofe.Z-t#-3E 7"e_f: V.D. T.1_31 -/6Correcfed fO /'mr/nile

0, 2 .4 .6 .8 LO L_ L4 L6 L8

L ,'ft coeffict'_nt, C,o

I-3/-35Cfed /o inf/_ife

..P .4 .6 .8 1.0 t2

L H't coeFF/cien_

/

12

/ (/

REPORT NO. 610--NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

Angle of o//ock, et (degre¢_)

.026 52

.024

A/A.CA. Z3012-34 R.N -/ZOote.2-1-35 Te$f: V O. "IT.IZEI -16Corrected/o/nF,;mYe ospecf Folio

":"4 "Z 0 .Z .# .6 .B /,0 l_ /.4 L6 /.8

L iF/coeff/c/en_ c,,

F_oua • 17.--N, A. C. A. 23012-34 airfoil•

TESTS OF RELATED FORWARD-CAMBER AIRFOILS IN THE VARIABLE-DENSITY WIND TUNNEL 13

=

75 1,9 )- 3.;/ " /{.,o 6,.,,_;[ o eo 40 so 80 oo ,.,oo 44

/5' '5'['4 '411 | Pe .... to#chord , .... t]-- _..tt_tI/ tt

20:._:9,'[-5#zL ....... ,

30]: o;I.5._t- ] t t I l ff 1 1 I t 1t .OZO - 4050 '7r 5, i0- '66 _ .6 ._ Yl _ 1 270:2; "3;Y! _ , .44 o.018 i80 , L 7 t 2. 73 " - - -

9_ ,'.o[ ./ ~ 20 40 _.-0163,5]'I, - ._0 " _ "

/0_ t I( -, 6) " -- - t]

T?-£.)_od2.zT48 I I_EH.R.N. I IJ_ 6 i . ] " ' _'Slope o f radlus -- " " 13

20 _0 40 _J ' - i; .._ i _ /2l_

" ....... t i-I--I-/_'t'4 t J/t t4 Fd ,,,a oo..... fl i,Y; oo.u

o_,oo--- r tvll _/L_.!l _ - .,,-' oe o -,, .,,.-_"' , _...__.,-=__.=U_=._.,o_e .o4 j-.t

o_. '-_'_"f'Ti I I 1 I ! l ! I ! I ! o o i-z o,o,','(-_,eodo;',;/4C_ _-._ _,__ A_rfol/.'N.ACA 23015 R,N:3,170,O05 -

Ve/(ff/sec.):6_.0 ch,or_dL--4 _. __._t'__3tze:,.5"X30" --Z " 13 -- I Jl-ll/Z

r Pres.(stride/re.):206 Date: 2"15-35 " _ A,_fo/I.'tLA.C.A. 23015 R.N[EE)8,370,O00 I..... Where tested" L.M.A.L. Test." VD.T. /23_ 4 _ , Dote.'2-/5-35 Test: V.D. T.1232j _

- 8 ...... Corrected {of tunnel-we//effect "" _ -"_ i Corrected 1o/_finife os_oecf rehb ___]-'_

-8--4----0 ,_ 8 12 16 20 24 P8 32 -4 _2 0 .2 .4 .6 .8 IO 1Z 14 L6 1.8

Angle of oftock, _ [degreeS) L/ft coeff/c/ent, c%

FIGURE 19.--N. A. (2. A. 23018 airfoil.

_, _ _, __ _o oz4 .... _;;:I :_,I- 5::;_I o 2o 4o 60 8o leo _. ,4.1/.' / '8, ;/" 6. 81 Percent of chord 1 .022 I

3,_ / .5; - Z _'741'' l 01 ' . _ '7 1 "OeO :: I _

S_ :Z; -5.. 4 - _ .018 -, _ 367.) :'/,_ .,t.,_Z 2.2 .44

k 9; .3., ../.._9 .... 2.0 .40

,o _" L.E.Rod.:3-5._ll Urff._N.L H._I [/1__.t/.a .3s ._..o/4 .... ze"_ f_g#;,_:N_z°_,'_e°_,°_°°L..kl1I 1--I ,._ .se _ _ +-

c_,,_-a:o,_oslll 3,800,0004. k l I/1 l • d ÷_24,____

,..£. t-- d=_d"qq F4-F.#..l t t,_-_,-_-,-[ -.- _ < __ ZO _ _0 t l-- -- I I _ ] I --f J @ V_' [ l--f'l t t t ";4 ".0_ .ZOO _1_6 < t-b-12 -_.

12 o ] -: .6 .ooe 4

. ....... : >_" - 12

o_ -- o o -.e .... e" ¢ _ _A,_fo;/./_ACA.23018 RN:3,090.OOO I i _ o.}e_ -_t",_/._'-

u ..... _.06C e6eve chord--- _-4"_ . '] _ .Size: 5"x30'" VeZfft/sec.): 69.3_ _ Z "- -.3 4 _ , 4- .... 12

% ' ] Pres.[sFnd.otm.):20.7 Dote:8-21-35] ' _ A/)-fo,'/..t¢.ACA. 2,.7018 _.N.(Eff_.'_,I_O, O00_ -- - ]-- Where _ested:L.MA.L. Tes/: YD._. 12861 4 E _ 4 Do/e: 8-21-35 . Test." V.D.EI286_-16

-o - 1--Correcfed for /unnel-waff effect I-" _ _ Corrected to=/nf_n/feOs/}ecf rot;o-8 -4 0 4 8 12 16 20 24 28 3Z =4 -_ 0 ._ .4 .6 .R LO /._ 1.4 1.6 L8

Angle of oltocA, c_ (degrees} L/F/ coeff/c/enf, c,,

FIOVRE _O.--N. A. C. A. 23018 airfoil.

._; . : ..

14 REPORT NO. 610--NATIONAL ADVISORY COMMITTEE FOR AERONAI_ICS

k

%.O

es_ o

Z4_ 2G

40

,e_so

_ o's,oo

-8

2._]5,_41 "3,141 k, '_ /0 Illl'_'J- _ "

7._ _. 3 s.,5 ..... / " _J__,.;b,.__I,. i_] 0=%0,o" _o 8o oo ___- ......... -J.... _.... ......I,'IIL_I Z i/I Percentofchord "I .U£_ __ 44

: 2}P_._Ol emL ' ........

6_ Y._9 z_;'- ' - - 44 018_ ...... 1..'i-L_ . I_l

I0 ) 12__) -._ 2) ..... ._ _-

0 .510 e o/trod/us -- _ ''_ ElfR.N a L-I#_tO_h end of - /_ 3 0

,.U

8_6/00ll it ..... 4"J,08 0--! _ / I I I't ,,_

" " =.... _ _-_-;" - .L--I/ : ! I-4_,o _$ .z .o4 _-.I--_

oc _ _-- [,_-_AZr(ol/.'N.A.C.A.Z302/, R.N.:3,,I'/O,o00I ou " _ (:.03,' ahead ofc/4 3--4" L__f_Llsize: s'xao" VeZ(ft.heo.): 6S.Tj- a _ - 3--i i_--_'07_£_°b_oovp c_°_C_d _ L:--' I__/2

_, L____Pres.(sfnd.otm.):20-$ Dote:B-17-3E I " _ " _ _ A;_fo;I..NA.C.A.23021, R,N _',EIC,O)O t

_ _ l[_Where fesfed..L,_A.L. Test: _D.T. 1285] 4 I_ 4 _]-_ l--3_'-_Corre_,edro,- _,.,,-,,-,,,_-,.,ot/_,.,_.c,1- _ _._ ao_e.._-/z-_5 r_._:v.o._.lz_ ,=

-- Corrected to /nf/nHe aspect faith _j-.u .

Amgle of attack, ot (degrees) L tiff coe ff/cienf, c,,

FIo_ra_ 21.'N. A. C, A. 23021 airfoil.

_,,,!4;i_,,fl i i__- .oeo .... : ...... 4o i

,eil!i :,li !l FFt:ll:ti-IFtITtA- ...o,o--2 :, :

+ -I-I-t-H-_ F_--+._L-4--H- ._ff d I 1 _-__kf% _ 1- 1.zc.z4_ _.ooe

± ,_xL _ -,.o_._o_._.oo_ _ _ j,it

J_ '_j_js;_:s'_ao" w/.m.l,e_.): _.e.-.z __ -.3j_ _[IPres.(sfnd.oim):20.4 Dole:4-20-34 _ 4jJqA,7fo;/.'N/I.C.A. 2#OI2, R.N,_ _)_2i,0,0(0 t

Dole.'4-20-34 Test:_V D. T. 1123 1l llWherefes,ed:LM.AI. Tesf.'IlDT./123_,._ _-"- j_._qqCorrecfedtoinfinifeospectrot/O_- ]] Corrected For ,unnel-wall effec_ _ _L ....... _"

-8 -4 0 4 8 12 /6 20 24 28 32 -.4 _2 0 .2 .4 .G .8 1.0 L2 1.4 1.6 I,E/

An_le of aflOC_, ot [degrees) L/F/coeff_bient, C,o

, @

TESTS OF RELATED FORWARD-CAMBER AIRFOILS IN THE VARIABLE-DENSITY WIND TUN_EL-_]5

FIGrRE 2_.--N.A. C. A. Z_012airfoil.

-8 -4 0 4 8 12 16 20 24 _8 3;2 .:4:2Angle of a/lock, _ (degrees)

"/10339 O 46 - 3 Fio_a_ 24.--N.A. C. A, 32012airfoil.

16.....'_ REPORT NO. 610---NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

r-

.026 Foz4 h

.OZZ f

•OZO

0 4 8 i_ 16 20 24 Z8 3_ =4 _

An_/e of of/oct, ee (degrees)

FIGU_ 2,5.--N. A. C. A+ 3,3012 airfoil.

0o_e:2-5-35 Test: V. D. T. 1224 -/6Correcfed fo ,'nf/n/te o,.s ecf r lio

0 .2 .# .6 .8 LO I_ /.# L6 L8

L/F/ coeff/c/en#, c,°

TESTS OF RELATED FORWARD-CAMBER ,_iRFOILS IN THE VARIABI, E:_ENSiTY :WTND-TUN-I_-EI,-_-_7- "

FIGURE _.--N. A. C, A. 4,%09 airfoil.

][8 " REPORT NO. 610---NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

?U

0

Z S_ G

24 ; BO

_ 20 _ 40..q

16 _- GO

"g_12_ 8o

e _ ,oo

QZ

(o-8

-8 -4 0 4 8 I_? 16 BO _4 28 32 T4 T2

Ample oF olfocA, _ [degrees)

FIc, r3RE _,--N. A, C. A. ,13012 MrfoiI.

\q/

+

d

-t,-I;

.I-

-I

t.-.

I -

_, _ _0_Dote..2-8-35 Tesf: V.D.7T1227Correcfed fo _f/n//e oSpec/ rOtiO

._q

-!I- 48-44

- 40

-- _z8 #

- r .l

-- -,0 _

-o}

-12

-IN

0 .2 .4 .6 .El ZO /.Z /,4 L6 L8

L/'ff ¢oeff/cienf, c_=

TESTS OF RELATED FORWARD-CAMBER AIRFOILS IN THE VARIABLE-DENSITY WI_'D TUNNEL 19

:4 :-Z 0 .2 .4 .6 .8 /..0 L2 ,{.4 I.GZ /H coeff/c/enl, c,.

FIGUR_ 32,--N. h. C. A. 4_I_ airfoil.

2O REPORT NO. 610---NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

,' II0.9 . .,Y 7_.;_ 1//.9, 44; O0t'_ 113.0 56;?( i_35 -6_5:

)_ 175, . 74._if(_78 -Z4'

o

0"b

zs_

24 _ ZO

_o2o _ 4o

_4 o

KIZo 80

_ e'alOO

._. _._o_.

._.

-4_.

-8

I

-8 -4

lil i- .......',-. 44

I.S .3z 8mz",, - I L. .... I ,| _,

14 .los _OlO - i .... i.... eo._ __.z_, .z#_ _ 008

/.o_ .zoo_.oo_

.e_.m_ .004o

.2 .04 _ -.I z

AL-fo//." /q.AC.A. 43021, R.N.[ -_., !8, _ _ ,0 )0}

Dote.'8-3t-35 Test: V. D. T. 1290 j_/_-.4 _- . Co?recfed tO _finife ospecf rot/o __

0 4 8 /,2 /_ ZO 24 _8 3_ _4 -_ 0 ,2 .-I .6 .8 I0 /Z 14 16

Angle of ollock, ce (degrees) Lift coeff/cienf, c,°

Fioum_ 33.--1%'. A. C. A. 43021 airfoil,

t.o

U%.O"o

24 _ ZO

b 16....60

,_ o._.

-4_,.

-O

;:_;',;l:',-$°] 4'_-'°O+H_ _t _ - H .oz_H -:Z6 7321-_.301 _U..LL,_ ._J _l_-__ L4 L..t. i ....

95,o,I_i_I---[ 1 ,_.,;L._,-_-q-FC/_z.o .,o .-.o,_H

S;o_e of?od/usf -- V_--V-T-T]_'_I- l-- r--] _ f-t-

I I --L[ -- - lZ-, _, _ _1 "i ...... • ',5 .Z4..__.008 _"

_= _,-- -- I, Oe _0 0 kO06

' ___L_--- S,ie: E'x30" Ve/,(_JecJ: 68.2J-_ _, - 3L-[L I I Pre=.(_'_o_):ZO.O Oo_e: Z-//-SS t" $ " L[ A,'r-_o;7;_A.CA_ItZO_ _._(J;-&50&_-

7q [_L_Where_ested:L.A_A.L. TenhV.D.T.tZZa| 4 _ 41 t Oofe:2-/t-35 Test:V.D.T./ZZet,

-8 -4 0 4 8 t2 1_ ZO Z4 Z8 3Z z4 :2 0 ._ .4 .6 .8 10 tZ 14 16 1.8

Angle of ol#ock, ix [degrees} Lift coeff;cien#, c,.

FIO,VRE 34.--N, A. C. A, 44012 airfoil,

TESTS OF RELATED FORWARD-CAMBER AIRFOILS IN THE VARIABLE-DENSITY WIND TUNNEL. 21

LO

O

"b

Z8 _ Qt3

24 _ 20

20 _ 40

_ iz_ 8o

e_ ,oo

_o_.12

-8

5.1qll.O;: - .2 Q112._rl" g./

7)i,l/g.8_pk S.._ 0 20 40 GOl: 136 P " $01 Percent of chord .02_ -

3_1/_1,'1.6.e ] _ t i t -1 - F1-- .020 .......4_)1331H' ZO ' -- "51l #1,9_' ' 6. G -_,,U,o.,,,_.,.,,_1t- !t t t - _£ ..,., o,,....7} 8.0 .48 _"_',,',:::o :tt t l _t : ti=_o ,o : o,ol,o)-_ lift _ _ i&,o ,, _o,,Slope of radiu$ -' _,,|,_271 _.[T II- -[_ ^_ _ _,fhroughendof -, 4'" '_" 3L_ ,L -_--}---I16 .d_ 0012cho_d: _._7e k'.!/( 6 '11/ / I t ' , u.

.... ' t- - CJ

__ -: _.0_.zoo ¢.oo_

:! t _

• i N.ACJ62()Zl RAZ.'319O[O0_O..... : .......... 7 U._ /- $'ze : E'_ 30" Ve/.(f_.lsec.) : 68, 7 j- 2 -- - 3

l |" Pres.(st_dalm.):ZO.8 pale: lO-lO- 351 " _, "

-8 -4 0 4 8 12 16 ZO 24 Z8 32 :4 rZ

An(_le of at/ark, (Y (degrees)

FIGU_ _.--N. A. C. A. 82021 airfoil.

J

J :

1

t:i

4 t::,-I?1fJ:_:d_ }J::::?/I::_'i "

t i -l-i i-_-t;i-> _I:-"{! -I l ,.i.' P r_ __

11;i7i¢1: !]!i 77: :7I _1T21;I:lT_tAl-W._-_L_:KI-,,IMrfoiI: N.A.C.A. 6Z021 _.,_ (£ff): 8A20,O001_of_: 10-10-35 Test: V.D. T. 13111 ,_

affected to "in fr]n/fe aspect ro#;o }-'_

0 2 .4 .6 .8 /0 iZ Z4 l&Lit! coeff/c_enf,C,o

FIoU_: _,.--N. A• C. A• _ airfoil.

22 REPORT NO. 610--NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

5Z

48

4_

_o

36}3Z .

ze_L

z4 *6

12 ._L

O_-kU

o_

-8

-/6

Fmo_ 38.--N. A. C. A. 63015 alrfoIl.

TESTS OF RELATED FORWARD-CAMBER AIRFOILS IN THE VARIABLE'DENS]TY WIND TUNNEL--_-23

=4 :Z 0 .Z .4 .6 .8 1.0 lZ L4 /.G L8L /ft coefG'c/ent, Go

FIGURE 39.--N. A. C. A. 63018 airfoil.

Sta p "7 I ,wtr. _ ) ' '6 _ _"

--: - "-, '_ -r _ _ 026o - o _ ,i '[-'_r" " '

,'o1_'.! _/ _:,_l o zo 4o 60 80. /oo _15 I_ rZ ;l _'.e2] Percenf of chord .vL(-20f _: )1 4.831

I_o_lii:; _.g - - - - ozog!i!i _ .... __ .,,,,"70 _'.) *.3_ . ;01880 "/. _ 32 / - -- ._

,._; ,.o, z.o .4o _.o_s

"_ ,_z_9_i _rs.,,o,oo:ttt lFkf .... %__1tc_ord:O.el'_-'l -r_zo.,oo_T.t It It T "_ '"_. 8'"'_'128 "h o_ ! " - :. _ e,

- --I-I--- _- -_ "_ l J

I I :- t I / 1.7_,- I L#[ 1_ _ o_'_ I_o _ 4o-1-[ -_ T _T- __ I I t-I i• l.o._._oo_.oo_

,q o .... .u _,

,z{ _o : ._._.,2 .002 :

o;.;-8 G 7 _7 _- Wher-ele_fed-L.MA.L. Te.q..VD.T. IZ_q/ 4 _ 4 [

._L_[ q Correc_ed for lunnel-wal/ eftecf -" _o -" .lL

5Z

48

44

_o _,g,

28 0

._./2 k

4_OO

-/6

-8 -4 0 4 8 12 /6 20 24 Z8 3_. T4 ":g 0 .2 .4 .6 .8 /.0 L2 L4 /.6 L8

Angle Of offock, _t (degrEes) Lift coeff/c/eni; C,,

Fl_,tJ_tZ 'IO.--N. A. C. A. 6302! airfoil.

.... e24 REPORT NO. 610--NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

TESTS OF RELATED FORWARD-CAMBER AIRFOILS IN THE VARIA-BLE-'-I)E_'_N'_-TY WIND TUNNEL 25 .............: , _: 2

0

Z8 0

_4 2_

.2 8:/00

4"

"2_ -4._.

StY= )°r L_

_r.

_I _i -;:/_I 0== -,_:

0 _,"

_' 41 -- .

S "t 72 --*

/C,m '0_ (-_ -_ __L.E. Rod.: 0.00

Slope of roc/_Js

f_. OcKzh end ofcho_ de." O.305

,r

- -8 -4 0 4 8 12 16 20 24 *With _ph'f

An_/e of oHoclL _x (degrees] flap deflected GO ° Lift coefficient, C,o

F]cJUR_ 43.--N, A. C+ A. 23009 airfoil with 0.2c split flap deflected 80 °.

.024

.OZZ

.OZO

.018

.44

4Z.O .40 .,:,014

Z8 .36 ._IZM

1.6 .3Z

-.4

-I_ -8 -4 0 4 8 /Z I_ 20 24 .Wifh spHf 0 .Z .4 .6 .8 LO Zg /.4 /..6 L8 2,0 £2

Angle oF oHock, _ (degrees) flop deflecfed GO" LFH coeff/clenf, c,,

F]OI_]¢ OI.--N. A. C, A. 23012 airfoil with 0.2c split flap deflected _ .....

REPORTNO.610---NATIONALADVISORYCOMMITTEEFORAERONAUTICS

.OZ4 f

.022[

.018

,44 _.016

"_ 0/4_.0 .40 _.

1.8 .36 _.012

/6 .32 _.010

c_/.4 .28_

.024

.02Z

.SZ .020

-/2

-t6

__=

TESTS OF RELATED FORWARD-CAMBER AIRFOILS IN THE VARIABLE;DENSITY WIND TUNeFuL 27'

z$ 6/

15 9. t. 84|.$ 4/

_.( 96

"o8O _..g_ -El

f,l -

_/Ope O/ rod/usthrough end of

chord: 0305

28 0 ===

Z4 ZO -- -"_

_ /2. 8O

"g o J

4_, I

-8_ t- -

-12 -8 .-4 0 4 8 /_ /6 _0 24 *With spilt 0

Angle of oHocA, ef (degrees) f/op deflected 75 ° L/'H coefficient, c,,

FIGURZ 47.--N,A C.A. 23015airfoilwith 0.2¢splitflapdefle_cted75%

m28: ..... REPORT NO. 610--NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

ko

%.o

28_ o

/24_ 86

¢c "

.c:-4

_8"D ___

75b,,_g.I _ ,,tT_q4q-FF-==_+53.,e .to _' ,_ i L . L. '5"- -. 2,2 ] [ 4

o,,:.,. o.o o.o.o,oo. :[5 ] Zd :9 .. t3 I Percenf of chord I _ ]_0

_0 5]' Z ;5 , OC 000 - _ -.

,o /':e ':;4_ l .i __

L.E. Rod.:O.89 | l 12 i I I "k _ t I I " _" ._ _. _ _ . - --

chord: O6/0 t t. _r I ] I t I F_I 1 " q _" -

-:I_ :q:,f :E-tl.:lt41i4,2oot_ :IlLiCIt:___t:b---,i-- , :-: : - : i-I-1-!-44-i " _ _ "7<_'ff -]-Lt--T 9 Lfl t-I"F_H o o 2-_ [ : -_:_ : :: ':,._: _:_-:r__u1; 1-t I 4,_,.c._..,_oos_.k..a,bzo.oool Lg__-- " Lo.Coe'.,ohe,<_>f_/._; iv_ _I.L__.LJ_. J_Js_:s'_ao" vezm.l_.):sg._4-e _-!_ _ __:, ............. L. _L --_e

_ I jPres.(Sf'_d, ofm.):aO. 7 | _" F rA/rfo/L'/VA.C,A.4300,9"N RN.(Eff.)'8,100,O00! t_ _Tesfe_K'L.MA.L. Tesf:VO.T./388" 4tDCor/ecrea ro ,br/m're ospecr" r'or)£ ]- 0

-IZ -8 -4 0 4 8 IZ 16 _0 24 _WZlh spl;f 0 .Z .4 .6 +8 ZO /.Z /.4 i6 L8 _0

Angle or oftoc&, _ [degrees) flop deflected 75 ° L if/ coefficient, c,,

Fnotmg 49.--N. A. C. A. 43009 airfoil with 0.2c split flap deflected 75=.

0 : oIxo/,.,,!-o,lzs/,_:/I-/_15.0 | _.:.31 -/._17.517., Zl -/<I/015',; '01 - I.,I #5 19x21-/._1 _'o/t._ fl-_.,1251Y151 -_._I 3ol9.,o1-z.,t ¢o/e.,S1-3.15olz'_31-2_lSO|_.:51-z1 70 5+_o1-_+.1 801 t*.Zt-I.

"_ I _01140l-/.i19s _.cal- .:I ,l_o I ,/t)l( ./tzool-I o

_, I L.E. Rod.: 7.500 l$1o#e ofrod_"_ Ifhro(agh e_d of

,es,,o_!2*/t"6 #2_ 80

b I/t11 14

4

_e _ljltllt'4"_ L I [ L4 i

-e _ LLL IM4btT_

/i _,7_I-L'_L""_p,o_

,,,,,o,till;ii:i --I1 tII I-l_f2:_: .o_..,s_ .ooe Ip,

-l-4-tl_}_ii i i:.z/ ' _- :t/VA.C.A. 430t_* R.N: 3,120,O00 "_- _ "_.S,ze:5_x30,Vel(ft/sec):69.t:_ L> _=_,_ _ 07e obove cho -d__ ..... , ,--,_ o,'"euI:$ ;22k?°',_,o,.J:$;',.-., ,,_, .......

-12 -8 -4 0 4 8 12 16 20 24 *W,'/h soht O- _2--.4 .6 .8 /.0 ZZ L4 46 1.8 £0 2.Z 2.4

Angle of allock, c_ (degrees} flop deflecfed 75" L if/coeff/c/ent, c

FmuR_ 50.--N. A. O. A. 4,'101_slrroll with 0.2e ipllt fl-p defleet_ 75°.

TESTS OF RELATED FORWARD-CAMBER AIRFOILS IN THE VARIABLE-DENSITY WIND TUNNEL 29

lX25[346,-0.92 _-_ 0 -J---

25 _ 441 ,50

3ot9.5+ ._z - 3s

++++•+++ I+:Ii!i'- -_°_':_It: :-__ I-_ t-'J'2'l _'aToo, boo1z " _o]4 jo _ooi(io)L(.jo ) _ . ._, [ .

_ : [

[I ;"l !-1! ''i¢'A'c'A'l_3009_l R.AI.,3tlO.O00 I_L.S-I _._; .

-4". , :-I _. ....._, i'i__LJ:_P+';+'5.,0.+,.,,..,.oo.>.+,,+ _ ., _:_,<o;o+,_PPeS($#ndofm,)'Z08 9-10-35-'_ o -.+_- q.... _'T .....

-<_ il_j_ <o,-,-o_,+,,,o,-,+ooo,-+o,._-.-,-._1t _:: <-o,-,-+<,,<,,:,n,,,o,,oo.,<>oo,,-o,,oj_o-12 -8 -4 0 4 8 _ 16 20 24 28 _W/lh spli# 0 .2 .4 .6 .8 /0 /2 14 /6 Z8 20 22

Am_71e of o#/ock, _Tc_e_rees) flop deflecied 75" L if# coeff_cien4 C,o

Fmul%ll 51.--N. A. C. ,_.. 63009 aiifoil with 0.2c split flap deflected 75 °.

cHOICE OF BEST CAMBE'R I_O$ITION

The first restllts of an investigation of the effects of

placing the camber forward of normal positions were

reported in reference 2. These results showed that air-

foils with the camber well forward iiad improved char-

acteristics and that the 0.15c position was probably the

best except for the apparently high maximum lift of theN. A. C. A. 21012 airfoil. (See fig. 15 and table II of

reference 2.) Subsequently, the investigation was ex-

[_ tended to higher cambers. These'results (fig. 52) indi-

cate that. the 0+15c position is best for airfoils of mod-

erate thickness (12 percent c). Furthermore, when tl)edata for this report (including the data in references 2

and 3) were being prepared, an error was discovered in

figure 15 and table II of reference 2. The value of theuncorrected maximum lift for the N. A. C. A. 21012

airfoil plotted in figure 15 should have been 1.52 instead

of 1.62 and the corresponding value of C_,_,_ in table II

corrected for the tip effect should have been 1.57 instead

of 1.67. The basis for the qualified conclusion of reference

2 that stated the maximum lift coefficient of simple

mean-line airfoils to be unaffected by positions of cam-

ber less than 0.15c is thus removed. "The optimum

position of camber may now be definitely placed +at

0.15c; that is, the position corresponding to the mean-

line shape designation 30.

The rest of tills discussion will therefore be concerned

with the effects of airfoil shape on the aerodynatnic

characteristics of those airfoils whose camber position

Clmax

L6 -1-300 - '-

I

220 --_

.OlOe+°.,, q l

.006 .-+U

z•2E{--_ -;[--;....

1.4 .,, 8-

_ _+ ..... | .... _

__12--J ,-

I

__L- . h,

.04 .

-+-!+........7-_ LL ___

+--_ :- :I,-4-"!"""

---_,4 .... J- - + ......

t

i

r-

27#L J- '.]e .z4Comber posif/on/n?loci�on of chord

FIGuag52.--Variationwithcamber positionof maximumlift, minimum drag,andtli.eratioofmalimum]if.tto miD|ml]m{]ragforth_12p_rc_antthickairfoils+

is at 15 percent of the chord back of the leading edgeand will be concluded with a discussion of the choice

of the best thickness and camber.

.O08

.004

REPORT NO. 610--NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

Vlq T[4o

o __mF,e i -_ _i•A 230 ....

_ n 430 - --

.04 ,08 " ./_ .16Maximum thicknessinfractionofchord

FIOURZ 53.--Variatlonofminimum drag withthickness.

lii:I._-3- d._'_,,_ x_e -i

.o .04 .08 ./2 ./6 .zo

Maximum/hicknesx in fraction of chord

FlaUSE M.--Varlation of position of aerodynamic center with thickness.

-JSymmefrical seines

230 :,jo 430 ,, ....+ 6.30 i

_ iI

.o4 .o8 ./z ./8 .zo .z4Max�mum fhicknem$ /n fract/on of chord

FIOUFt¢ 55.--Variation of maximum lift with thickness,

o

VARIATION OF A]_RODYNAMIC CHARA(_TERISTICS WITH

SECTION SHAPE

The variation with thickness of the characteristics of

the airfoils reported herein agrees approximately with

previous findings, although the present results are

slightly different owing to their greater accuracy. The

added accuracy of the section characteristics is princi-

pally the result of corrections for turbulence and tipeffects (reference 6), which may also be applied to the

results presented _n reference 1. The minimum dragcoefficient increases in accordance with the relation

c_o_,=/c+O.O050+O.O033t+O.1t_ (fig. 53), where t is

the thickness ratio and k (which is approximately con-stant for sections having the same mean line) repre-

sents the increase in c_o_, above that of the symmet-

rical section of corresponding thickness. The lift-curve

slope decreases slightly for the thicker airfoils, and the

position of the aerodynamic center moves slightly for-

ward with increasing thickness (fig. 54). The pitching-moment coefficient and the optimum lift coefficient

decrease numerically with increasing thickness.

The maximum lift coefficient is highest for moder-

ately thick sections, as shown in figure 55. The greatestvalue of maximum lift occurs at a thickness near I3

percent for the symmetrical and 230 series but at alower _hickness for the 430 and 630 series.

Tests made to determine the optimum position ofmaximum thickness for an airfoil showed that the usual

N. A. C. A. thickness distribution is better than thick-

ness distributions having positions of maximum thick-

ness farther back. This conclusion is substantiated by

the results shown in figure 56.

The effect of filling out the concave portion of thelower surface near the nose of the N, A. C. A, 43012

airfoil and thickening the upper surfaces so that the

mean line is unchanged may be seen by examining thedata given in table I. The N. A. C. A. 43012 is seen to

be aerodynamically better than the N. A. C. A. 43012A.

A comparison of the results given in table I for the N,A. C. A. 23012 with the N. A, C, A. 23012-33 and those

:for the N. A. C. A. 23012-6.4 with the N. A. C. A.

23012-34 shows that the effect of decreasing the lead-

ing-edge radius below its normal value is to decrease

the maximum lift, which confirms the results of ref-erence 1.

The effects of camber changes upon the aerodynamic

characteristics of the airfoils shown in figure 1 also

agree with previous findings. The minimum drag

increases with camber. (See fig. 53.) The angle of

zero lift is proportional to camber and agrees with thetheoretical value (see reference 1) to within 0.2 ° for

airfoils of moderate thickness, The comparison of the

angle of zero lift with the computed theoretical value

is shown in figure 57. The diving moment is propor-tional to the camber and increases with a rearward

movement of the position of the camber as predicted by

.... _ . -- T

TESTS OF RELATED FORWARD-CAMBER AIRFOILS iN THE VARIA_LEU_-_-SiTY: W_ll_l) T6-NNEL_ .....

theorybut issmallerin magnitude than thetheoretical The additionof the splitflapmay be consideredas

value (fig.58). These and otherdifferencesbetween givinga maximum,liftincrement. This maximunj-lift .

theoryand experimentagreewith the findingsin refer- incrementincreaseswith thickness,as shown in figureenee I but have since been adequately explained. 60,but does not change appreciablywith camber.

(See reference 10.) CHOICE OF BEST THICKNESS AND CAMBER "

2.O I [ i Isir I [ [ Iodi_s_ In the selection of a member of this airfoil family for0 Symme#r&a/ aerie • normol L.E r

, 230 ]" ] I-- a given application, the choice of the best thicknessv 230 I _ *" _ I ....1.8 " ;'_ .... and camber to be Used depends on severalfactors,.

The Reynolds Number atwhich theairf0ilistobe used

cz=.= will be one of these factors. By means of the scale-

...... _ Thickness, p_rcen# chord

!° 9-- --° tl2"f-=_f-x 15-f'=_t- °18- -- _ 2'1.4 L.... ' CGwber position O. 15c

1.8 ....... --- _::_.=_= ...........

__ .==-==- -1.2 ..... q,,,.= _ ......_ _.._ _ ""-"_¢_'1 "-""

i _.- ..__....o--- _ _ ---._z#o---- __Z ____............

c_=._, ÷:_ =-- -----1-- + i "7- .........

28 ........................

/6O ..................... _ i ..........

.008................. _40_------'q_[._ -- "_ .o.. --- "_ ....._........ J/ =-

•006 -,_0 ./ .Z .3 .4 .5 .6 2001_-- ---- ! : ..... _ _ ......

Posit/on of maximum thickness in fracllon of chord . _ ,

FIGURZ 56.--Variation with position of maximum thickness of m_xtmum lift mini- -- -- -- I o I _ _ _ --

mum drag, and the ratio of maximum lift to minimum drag. /_0_-"'--" ..... -+ ..... + __ _

Comber position in fraction of chord + . , +_.04 .08 ._'_ .24 _ _ .........

" " /20 ..................

I) - -=-=-+ _ ..............

--_=_ _--F-_..--= .w-- _ _FIOUItg57.--Variation 0f angleof zero lift with camber IXmltlon. -- ....__ -.o-4 _ L _ ._ _ "

Comber poa+tlon in fraction of chord .0 .02 _04 .060 04 ,08 12 .16 20 24 Camb=er i_ froclion of cho?d

!o lttll [AL A I llil IJ

• : -- I FIGUttl 89.--Variation with _m_xlmum lift, minimuin drag, and-the --7

d t. _ ratio of maximum lift to minimum drag.d _ "_ effect classification given in table I and explained in

6 references 6 and 9, the variation of maximum lift andother characteristics with Reynolds Number for any

Fic_i 58,--Vm'latiot_of pitchingmoment withcamberposition, airfoilcan be found....

The maximum lift increases for moderate amounl_s of For simplicity, the following discussion is based oncamber, but this effect is less noticeable with thicker airfoil section characteristics corresponding to theairfoils (fig. 59). It may be mentioned that theln- standard conditions (effective Reynolds Number,crease of maximum lift with camber is more pronounced 8,000,000).. Such an analysis will apply approximatelyat reduced values of the Reynolds Number. (See ref- to an airplane such as a medium-size transPor t, which =erence 6.) lands at Reynolds Numbers near 8,000,000.

32

if a high cruising speed for a given landing speed isof primary importance, the ratio of maximum lift to

the drag at cruising speed cz.,.=/C4o,known as the "speed-range index," is a useful criterion of airfoil efficiency.

Z.8 • - -

Z.6_ ....

REPORT NO. 610--NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

f

__ deflec fed ___

1.6 , Withauf -_'---

c_._ ,,_

1.4 -:--

//.Z /

.8........._ due to flop.

.6

o 230 ser/e50430 .......+630 .

.4

I0 .04 .08 22 .16 .20 ._4

Maximum fh/ck/_e$s /m fraction of chard

FIGURZ 60.--Variation of maximum ll[t with thickness,

- Although other performance characteristics, such asrate of climb and length of take-off run, depend less onthe airfoil section characteristics than does the speed

range, the same criterion may also serve as a roughindication of these characteristics. In such cases, the

drag coefficient in the ratio c_,,=Jc_ should be taken ata lift coefficient corresponding to the best rate of climb

or to the shortest take-off run, respectively.

Inasmuch as the cruising speed generally occurs near

the lift coefficient corresponding to the attitude of

minimum profile drag, the ratio ct,,,_/e_o.,, may be used

as a measure of merit. The variation of this ratio with

thickness and camber is shown in figure 61, which

indicates that for thicknesses near the optimum (that

is, somewhat less than 12 percent c) the N. A. C. A.airfoils can be arranged in the following decreasing

order of merit as shown by the speed-range index:

230 series, 430 series, symmetrical series, and 630

series. For thicknesses only slightly greater than the

optimum, however, the index for the symmetrical seriesbecomes greater than for the 430 series and nearly equal

to that of the 230 series. Attention should perhaps be

called to the fact that the curves presented in figures. 61,62, and 63 are drawn to agree with cross plots of the

characteristics against thickness. Points are included

to show the experimental values.

TESTS OF RELATED FORWARD-CAMBER AIRFOILS IN THE VARIABLE-DENSITY WIND TUNNEL 33

Owing to the wide use of split flaps and other high-

lift devices in landing, the speed-range index should

preferably be derived from the maximum lift coefficient

with the high-lift device. Figures 61, 62, and 63 each

include curves showing the ratio of the maximum lift

coefficient with flap deflected to the drag coefficient with

flap neutral. The addition of split flaps does not affect

the optimum camber of the airfoils since the maximum-

lift increment is practically independent of camber at

flap deflections of 60 ° and 75 °. The addition of split

flaps will tend, however, to increase the optimumthickness of the airfoils, since the maximum-lift incre-

3.2o

285

246

2o0--

/6o

/go . .

80

4o

0

f

q

I

o S.wwmefr/co/ se_ es

i

.04 .08 32 .16

-- _ .--,_- . .

_l A , , •

\

,. i I

i

] i ,.ao .24

• 1

l

I

Moxlmum fhickn_$$ /n £rocfion of ChOrd

flG1_ax fl2.--Variatlon of ¢l-=Jc4O(ct=0.4),N with thicknes_.

ment with flaps increases with thickness: (See fig. 60.)

Thus the thickness for the highest value of cz,,Jc%,,,

for the 230 series increases from 9 to 11 percent (approxi-

mately) with the addition of the flap. (See fig. 61.)

Particular design conditions, such as high-altitude

flight, high wing loadings, and long-range flight, require

that the airplane fly most efficiently at a certain lift

coefficient that may be higher than cz=,. For such

applications the useful criterion is the ratio ct.==/cdo

where c_o is taken as the value corresponding to thiscertain lift coefficient.

A comparison of the N. A. C. A. forward-camber air-

foils, based on their drags at a lift coefficient of 0.4, is

given in figure 62. The order of decreasing merit for

thicknesses between 10 and 12 percent is then changed and

becomes 430 series, 230 series, 630 series, and symmetri-

cal series. As before, the addition of a flap will not

markedly affect the relative merit of the airfoils for any

given thickness but will increase the value of optimum

thickness for any given camber.It may also be desirable to compare these airfoils on

the basis of a cruising speed corresponding to a liftcoefficient of 0.6. The results, which are shown in

"l" , ,. i t

Syrnmetrlco/ series

oA0

* 8ooI I :l

:¢.-_

. \W/fh" a_e Spill 7o,o

de£/ecfed 75 °

//

/

\

0 .04 .08 .12 ./6 ._0 • g4Maximum /hicknemj in £rocf/on of chord

Fioux= 63.--Variation of ¢l_=Jca . with thtcknee_."_, -0.6)

figure 63, indicate that the 430 series now becomes supe-

rior to the 230 series over the entire range of thicknesses

tested and the symmetrical series becomes definitelyinferior.

Finally, structural considerations will dictate the

choice of an airfoil thickness and a wing shape that will

efficiently support the aerodynamic loads. This re-

quirement will lead to the choice of an airfoil that is

thicker, in general, than one selected solely on the basisof aerodynamic requirements. The final selection of

the best thickness and camber will resul.t in a compro-

mise between the demands of aerodynamic and struc-

tural efficiency.

r

34 REPORT NO. 610---NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

The general factors determining the choice of thebest thickness and camber have been only brieflydiscussed. The requirements of any particular airplane

design will determine exactly what airfoil will be bestsuited to that application. It should be emphasized,for instance, that for small airplanes landing at Reyn-olds Numbers much below 8,000,000, section char-acteristics should be corrected by means of the method

given in reference 6 to the design Reynolds Numberbefore comparisons to determine the optimum sectionsare made. Such a comparison will show that the

optimum camber is considerably higher at the lowerReynolds Number than that indicated by the preced-ing analysis. For most purposes, a camber of 2 to 4percent and a thickness slightly above that of themaximum speed-range index will usually be chosen.Some unpublished investigations of particular easesindicate that it is inadvisable, in any case, to depart

very much from the optimum airfoil shape dictated bypurely aerodynamic considerations unless structuralconsiderations definitely justify the departure.

LANGLEY MEMORIAL AERONAUTICAL LABORATORY,.

NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS,

LANGLEY FIELD, VA., December 5, 1936.

REFERENCES

I. Jacobs, Eastman N., Ward, Kenneth E., and Pinkerton,Robert M.: The Characteristics of 78 Related Airfoil

Sections from Tests Jn the Variable-Density Wind Tunnel.

T. R. No. 460, N. A. C. A., 1933.2. Jacobs, Eastman N., and Pinkerton, Robert M.: Tests in

the Variable-Density Wind Tunnel of Related Airfoils

Having the Maximum Camber Unusually Far Forward.T. R. No. 537, N. A. C. A., 1935.

3. Jaeobs, Eastman N., and Pinkerton, Robert M.: Tests ofN. A. C. A. Airfoils in the Variable-Density Wind Tunnel.Series 230. T.N. No. 567, N. A. C. A., 1936.

4. Jacobs, Eastman N., and Clay, William C.: Characteristicsof the N. A. C. A. 23012 Airfoil from Tests in the Full-

Scale and Variable-Density Tunnels. T. R. No. 530,N. A. C. A., 1935.

5. Platt, Robert C.: Turbulence Factors of N. A. C. A. WindTunnels as Determined by Sphere Tests. T.R. No. 558,

N. A. C. A., 1936.6. Jacobs, Eastman N., and Sherman, Albert: Airfoil Section

Characteristics as Affected by Variations of the Reynolds

Number. T.R. No. 586, N. A. C. A., 1937.

7. Stack, John, and von Doenhoff, Albert E.: Tests of 16Related Airfoils at High Speeds. T. R. No. 492, N. A.

C. A., I934.8. Jac_)bs, Eastman N., and Abbott, Ira H.: The N. A. C. A.

Variable-Density .Wind Tunnel. T. R. No. 416, N. A.

C. A., 1932.9: Jacobs, Eastman N., and Rhode, R. V.: Airfoil Section

F • •Characterlstms as Applied to the Prediction of Air Forcesand Their Distribution on Wings. T.R. to be published,

N. A. C. A., 1938.10. Pinkerton, Robert M.: Calculated and Measured Pressure

Distributions over the Midspan Section of the N. A. C. A.4412 Airfoil. T.R. No. 563, N. A. C..A., 1936.

0

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