<%BANNER%>
HIDE
 Front Cover
 Main
 References
 Tables and figures
 Back Cover


FDLP



Wind-tunnel investigation of aileron effectiveness of 0.20-airfoil-chord plain ailerons of true airfoil contour on NACA ...
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/AA00009394/00001
 Material Information
Title: Wind-tunnel investigation of aileron effectiveness of 0.20-airfoil-chord plain ailerons of true airfoil contour on NACA 65₂-415, 65₃-418 and 65₄-421 airfoil sections
Series Title: NACA WR
Alternate Title: NACA wartime reports
Physical Description: 9 p., 8 leaves : ill. ; 28 cm.
Language: English
Creator: Braslow, Albert L
Langley Aeronautical Laboratory
United States -- National Advisory Committee for Aeronautics
Publisher: Langley Memorial Aeronautical Laboratory
Place of Publication: Langley Field, VA
Publication Date: 1944
 Subjects
Subjects / Keywords: Aerofoils   ( lcsh )
Aerodynamics -- Research   ( lcsh )
Genre: federal government publication   ( marcgt )
bibliography   ( marcgt )
technical report   ( marcgt )
non-fiction   ( marcgt )
 Notes
Summary: Summary: An investigation was made in the NACA two-dimensional low-turbulence pressure tunnel to determine the aileron effectiveness of 0.20-airfoil-chord plain ailerons of true airfoil contour on the NACA 65₂-415, 65₃-418, and 65₄-421 airfoil sections. The aileron effectiveness parameter (change in section angle of attack with aileron deflection at constant lift coefficient) decreased very slightly with an increase in airfoil thickness from 15 percent to 21 percent. At higher deflections of the ailerons and higher section angles of attack, the increment of section lift coefficient due to aileron deflection was more appreciably reduced with an increase of airfoil thickness than was the aileron effectiveness parameter.
Bibliography: Includes bibliographic references (p. 6).
Statement of Responsibility: by Albert L. Braslow.
General Note: "Originally issued August 1944 as Advance Confidential Bulletin L4H12."
General Note: "NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution of advance research results to an authorized group requiring them for the war effort. They were previously held under a security status but are now unclassified. Some of these reports were not technically edited. All have been reproduced without change in order to expedite general distribution."
 Record Information
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 003806709
oclc - 124096817
System ID: AA00009394:00001

Table of Contents
    Front Cover
        Front Cover 1
        Front Cover 2
    Main
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
    References
        Page 6
    Tables and figures
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
    Back Cover
        Back Cover 1
        Back Cover 2
Full Text
. ,- .
.fj^cu L-flZ


--U*


CB No. L4H12


NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS






WATRTIMi'E REPORT
ORIGINALLY ISSUED
August 1944 as
Confidential Bulletin L4H12

WIND-TUNNEL INVESTIGATION OF AILERON EFFECTIVENESS

OF 0.20-AIFOIL-CHORD PLAIN AILERONS OF TRUE

AIRFOIL CONTOUR ON NACA 652-415, 653-418

AND 654-421 AIRFOIL SECTIONS

By Albert L. Braslow

Langley Memorial Aeronautical Laboratory
Langley Field, Va.




^ r ^ -y,, -t - : ,. . ,-r4 f ... ..... :.- .

..NACAA-
'

'S .**.*


A':.
* 2i


WASHINGTON

NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution of
advance research results to an authorized group requiring them for the war effort. They were pre-
viously held under a security status but are now unclassified. Some of these reports were not tech-
nically edited. All have been reproduced without change in order to expedite general distribution.


L 178




































Digitized by the Internet Archive
in 2011 with funding from
University of Florida, George A. Smathers Libraries with support from LYRASIS and the Sloan Foundation


http://www.archive.org/details/windtunneang







".CA CB No. L4H12

NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS


CONFIDENTIAL BULLETIN

WIND-TUIT'EL I TS'"STIGATION OF AILEROI EFFECTIVENESS

OF' 0.20-AIRFOIL-CHORD PLAIN AILERONS OF TRUE

AIRFOIL CONTOUR ON NACA 652-415, 653-418

AND 654-L21 AIRFOIL SECTIONS

By Albert L. Braslow


SU] :.T ARY


An investigation was made in.'the NACA two-dimensional
low-turbulence pressure tunnel to determine the aileron
effectiveness of 0.20-airfoil-chord plain ailerons of
true airfoil contour on the NACA 652-415, 65 -418, and
6541-21 airfoil sections. The aileron effectiveness
parsmeter (change in section angle of attack with aileron
deflection at constant lift coefficient) decreased very
slightly with an increase, in airfoil thickness from 15 per-
cent to 21 percent. At higher deflections of the ailerons
and higher section angles of attack, the increment of
section lift coefficient due to aileron deflection was
more appreciably reduced with an increase of airfoil
thickness than was the aileron effectiveness parameter.
The slope of the airfoil section lift curve cz was

substantially the same for the three airfoils tested.


INTRODUCTION


The use of low-drag airfoils has led to increased
wing-tip thickness ratios for the purpose of improving
the aerodynamic characteristics of the wing. Without
causing much increase in drag, these larger tip thick-
ness ratios of low-drag wings increase the low-drag
range, improve stalling characteristics, and decrease a
shift in span load distribution when compressibility
conditions are encountered. This trend toward the use


rl '









2 CONFIDENTIAL NACA CB No, L4H12


of thicker outboard low-drag airfoil sections has led to
the desirability of securing data regarding the effects
of thick airfoils on aileron effectiveness.

The purpose of this investigation was to determine
the aileron effectiveness of 0.20-airfoil-chord plain
ailerons of trueairfoil contour on the NACA 652-415,
653-L 8, and 65 -h21 low-drag airfoil sections. Tests
have been made in the YACA two-dimensional low-turbulence
pressure tunnel at a Reynolds number of approximately
6 x 10 and a :Sch number less than 0.15. Lift measure-
ments were :jrde at ailleron deflections through an approxi-
mate range from -200 to 200.


S SYo. ..DL AND COEFFICIENTS


The symbols and coefficients used in the presenta-
tion of results are as follows:

Qo airfoil section angle of attack

cz airfoil section lift coefficient

c airfoil chord.

? reynolds number

Acz cz with aileron down minus c, with aileron up

ba aileron deflection with respect to airfoil
cla= (6ce/zao)5a=Oo (measured at ao = 0)

C1 a= (bo/a)ao=00 (measured at 5a = 0)


(6ao/66a)c, aileron effectiveness parameter c


DESCRIPTION OF MODELS AND TEBT ,IETHTODS

The three models, of 2h-inch chord, were constructed
at the Langley ..--Yrrial Aeronautical Laboratory and had
CONFIDENTIAL


! ....


--










NACA CB No. LL4H12


IACA 652-1 5, 653-418, and 654-421 airfoil sections; the
ordinates of these airfoil sections are presented in
tables T to TII. The models were constructed of laminated
mahogany, painted with lacquer primer surface and sanded
smooth, and were equipped with 0.20c plain *ailerons of
true airfoil contour made of solid dural to minimize span-
wise deflections of the aileron under load. The aileron
gaps were sealed with modeling clay for all tests.
Drawings of the ailerons are presented in figure 1.

The models spanned the rectangular test section, and
section lift coefficients were obtained with a manometer
arrangement that integrated the lift reaction of the
model on the floor and the ceiling of the wind tunnel.
Section lift coefficients and angles of attack were
corrected for tunnel-wall effects according to the
following formulas:

c = [1- 2p(Y + ) 7~ c

ao = (1 + Y) ao

where

cL' airfoil section lift coefficient measured in tunnel

ao' airfoil section angle of attack with respect to
free-stream tunnel ai'r

p factor dependent on airfoil shape

Y factor dependent on ratio of airfoil chord to
tunnel height

o factor allowing for interference of model on
static-plate pressure; dependent on size and
location of model

The values of I 2p(y + o) y were 0.975, 0.973,
and 0.971 for the NACA 652-415, 653-418, and 654-L21 air-
foil sections, respectively. The quantity 1 + y was
equal to 1.015 for all three airfoils.


CONFIDENTIAL


CONFIDENTIAL










NACA CB No. L]H12


RESULTS AND DISCUSSION


Plain-airfoil section characteristics of the three
airfoils tested are given in:-reference 1. The section
lift coefficients presented herein may differ slightly
from those in reference 1 as a result of improved cor-
rection factors used for the present calculations.

Aileron effectiveness is measured by the change in
section angle of attack per unit aileron deflection at
a constant c7. The value of this parameter varies
with aileron deflection and usually becomes smaller with
larger deflections. As the aileron deflection is decreased,
the effectiveness approaches a limiting value equal to
ca I c/ or (6ao/66a)c which is used herein for

purposes of comparison.

Lift characteristics of the airfoil sections tested
are presented.in fi 'res 2 to ) for several aileron
deflections approximately from -20o to 20. The varia-
tions of c C and (6ao/6a)c with airfoil

thickness are presented in figure 5. The value of cL,
for the three airfoils tested remained substantially
constant; the values ranged from 0.112 for the 15-percent-
thick airfoil to 0.111 for the 21-percent-thick airfoil.
The. value of (ao/65a)c decreased very slightly from
0.479 for the 15-percent-thick airfoil to 0.l66 for the
21-percent-thick airfoil. The average 'value of
(6ao/66a)c for the three airfoils tested is approxi-
mately 36 percent of the value predicted from thin-airfoil
theory (reference 5) and is 5 percent greater than the
value obtained on the NACA 0009 airfoil as presented in
reference 2 (also shown in fig. 5).

A more pronounced effect of airfoil thickness on
aileron effectiveness occurs at the higher aileron
deflections and section an-les of attack at which the
air flow over the aileron has separated. At the higher
section angles of attack, the increment of section lift
coefficient due to total aileron deflections of 100,
150, and 200 decreases with an increase of airfoil
thickness as shown by the curves of Ac, plotted against
ao in fi r--s 6 to 8. For a total aileron deflection
COIT DE!TTiAL


CONFIDENTIAL










NACA CB Fo. LlT12


of 150 at a section angle of attack of 120 (fig. 7),
the Ac, available for the 15-, 18-, and 21-percent-
thick airfoils is about 56.3, 50.3,and 44.5 percent,
respectively, of the theoretical value, of Ac,. The
theoretical value of Acn was calculated by using
thin-airfoil values of 2Tr/57.3 for the lift-curve
slo"e c7 and 0.55 for ('a ,/6a)c obtained from
reference ~.


CONCLUDING ?EMvARKS


The aileron effectiveness parameter (change in
section angle of attack with aileron deflection at
constant lift coefficient) decreased very slightly with
an increase in airfoil thickness from 15 percent to
21 percent for the VACA 652-415, 653- ,18 and
65 -L.21 airfoil sections. At higher deflections of the
0.20-airfoil-chord ailerons and higher section angles of
attack, the increment of section lift coefficient due to
aileron deflection was more appreciably reduced with an,
increase of airfoil thickness than was the aileron effec-
tiveness parameter. The slope of the airfoil section
lift curve cZ was substantially the same for the three
a
airfoils tested.


Langley Ternorial Aeronautical Laboratory
National Advisory Committee for Aeronautics
Langley Field, Va.


CO IDEFTIAL


'COFITDEFTIAL










NACA CB No. L4H12


REFER TEN-S


1. Jacobs, Fastman N., Abbott, Ira H., and Davidson,
'ilton: Preliminary Low-Drag-Airfoil and Flap
Data from Tests at Large Reynolds Numbers and Low
Turbulence, and Supplement. NACA ACR, March 1942.

2. Ames', ''ilton B., Jr., and Sears, Richard I.: Deter-
mination of Control-Surface Characteristics from
":ACA Plain-Flap and Tab Data. iACA Rep. N1o. 721,
191.

5. Glauert, IH.: Theoretical Relatoionships for an
Aerofoil with Hinged Flap. R. &8 IT. No. 1095,
British A.R.C., 1927.


COITFIDE rTIAL


COI'FTDE NTIAL









ITACA CB No. L4H12 CONFIDENTIAL


TABLE I.- ITACA 652-415 AIRFOIL
tStations and ordinates given
in percent of airfoil chord]


NATIONAL ADVISORY
COMMITTEE FOR AERONAUTICS


CONFIDENT AL


Upper surface Lower surface
Station Ordinate Station Ordinate

0 0 0
.312 1.216 .688 -1.016
.541 1.181 .959 -1.201
1.017 1.,93 1.485 -1..65
2.231 2.677 2.769 -1.955
L.697 5.865 5.305 -2.601
7.184 .795 7.816 -3.099
S.632 5.575 10.518 -5.507
L.697 6.81 15.530 -4.149
1. 726 7.807 20.27 -4.625
2L.764 8.547 25.256 -4.967
2.8 07 9.000 30.195 -5.202
.854 9.455 5.146 -5.355
'.905 9.637 0.097 -5-553
.L.953 9.617 5.0L7 -5.237
o.0oo0 9.371 50.000 -4.957
5. ok3 8.908 5h.957 -L.52
68.079 8.25 539921 -35.97
5.:o6 7.45 6..894 3.558
7. 12 6540 69.876 -2.652
,5. 151 .550 7.869 -1.950
i:.12 6 .47 9.874 -1.265
S. 1o 3.320 :.891 -.628
O.080 2.175 89.920 -.107
Sol,.oo 1.057 94.960 .207
10C o 100 0

L.E. radius: 1.505
Slope of radius through L.E.: 0.168









NACA CB No. L4H12


TABLE II.- NACA 655-418 AIRFOIL
[Stations and ordinates given
in percent of airfoil chord]


NATIONAL ADVISORY
COMMITTEE FOR AERONAUTICS


COIDFIDEi TIAL


Upper surface Lower surface

S t tion Ordinate Station Ordinate
0 0 0 0
.278 1.418 .722 -1.218
.503 1.729 997 -1.449
.973 2.209 1.527 -1.781
2.11 5.104 2. 19 -2.5360
L.639 L.481 5.561 -5.217
7.1253 5566 7.877 -5.870
q.619 6.478 10.381 .1lo
1L.636 7.9bl2 15.564 -5.250
19.671 9.061 20.52 -5.877
2)4.716 9.914 25.284 -6.
29.768 10.556 50.232 -6.6
53.125 10.9 4 5. 175 -6.82
.988 11.140 o o0116 -6.856
4L.915 11.091 45.057 -6.711
50.000 10.774 50.000 -6.362
55.051 10.19L 54.94c9 -5.818
,:.o941 9.408 59.90 -g.24
65.126 8.454 668 -4.7 4
7n.146 7.568 69 8 -3.80
75.157 6.18-20
c'o.147 4.927 79.855 -1.743
85.127 3.68 84.875 -.946
-'0.092 2.350 89.908 -.282
5.0o46 1.120 9..954 .144
10,1 0 100 0

L.E. radius: 1.96
Slope of radius through L.E.: 0.168


CO'TFTDEI;TIAL









IJCA CB No. L4H12


TABLE III.- NACA 654-4L21 AIRFOIL

[Stations and ordinates given
in percent of airfoil chord]


Upper surface Lower surface

Station Ordinate Station Ordinate

0 0 0 0
.216 1.609 .754 -1.409
.468 1.950 1.052 -1.070
282 1.565 -2.054
2.14 35.507 2.866 -2.763
SL. 5.079 5.41 .15
7. ''2 6.528 7 -4 632
.557 7.562 10.L4,? -5.294
.451.6 9.051 15.424 -6.559
19.i6 10.500 20.584 -7.116
2.. 668 11.267 25.552 -7 687
29,729 11.972 50.271
z54716 12.4 5 5.204 -851
1.i5 12.6 o 40.15 .356
L.54 12.549 45.066 -8.169
c: .~ 2.145 50.000 -7735
5. -59 11.456 54.94 .076
*.l8 10.525 59-892 -62
L.k5 9.470 64.855 290
70. 6 8.157 69.832 269
75.175 6.862 7e.825 -3.222
',..lo7 5.581 7 ,.855 -2.197
.5.ci3 .957 8 .857 -1.245
,:.103 2.511 89.8 7 4
-.051 1.176 94.99 .088
100 0 100 0

L.E..radius: 2.50
Slope of radius through L.E.: 0.168


NATIONAL ADVISORY
COMMITTEE FOR AERONAUTICS


COI FIDE 'TIAL


CONFIDENTIAL









NACA CB No. L4H12


-415 AIRFOIL


NACA 653-418 AIRFOIL


NACA 654-4I2 AIRFOIL


NATIONAL ADVISORY
COMMITTEE FOR AERONAUTICS


Figure 1.- Sealed-gap 0.20c plain ailerone of truck airfoil contour on
NACA 652-415, 653-418, rni 654-421 airfoil sections.


CONFIDENTIAL


CONFIDENTIAL


Fig. 1


L.E. -------.0c









NACA CB No. L4H12


CONFIDENTIAL


4




-1






O 21 ---
-- -- o





F1tr 2- L 110 25'-he nA--A-6i-i-


-1 _o 01o:r























_b sal--- -gap SO.0t ai n an le o o .t r_ __e a io ilnoe_..-, 6 -6
1- A-





appox.); es D 605.
-- i--- -
r - : _-t i ,





-I-4
sci ;-gl-e oatk---- -- -- -- -
(apo .) -e- 65--



CON I DENI





... ___- _ _! _ _


Section angle of attack, ao, deg 1 - _

Frgre 2.- Lift charaoteristice of an HACA 652-415 airfoil section equlppeid
with sealed-gap 0.20c plain aileron of true airfoil contour; R, 6 x 100
(approx.); test, TDT 605.
CONFIDENTIAL


Fig. 2








NACA CB No. L4H12


. .i. I
- -,-I ___ ;_ -


71-
i-V-' ~-


+E4'F "Ri T TN-W F


-P

S a T
S---0 5
1a 0 --
1 :- :,L

0 -19 55' -
PFT i I"
L^^rs^ 2;
j *ft-- v -^, B5'
c^^ -i--gr0 5


,tflriLt H iL


*. -4 . < ,/I


v ** J -T


attack, a aeg


Tv I AW 4I V 'T7 ,I


-_-, Section angle of


Figure 3.- Lift characteristics of an NACA 653-418 airfoil section equipped
with sealed-gap 0.2Qc plain aileron of true airfoil contour; R. 6 x 106
(approx.); test, TDT 629.
CONFIDE ENTIAL


1+miE


0
0 .0 00'-
t- 50 00'-
X 10 00'-
0144 55'-
020 10'-

- 3
.-_ 4J


421


i-t
I-

S-^
a











7LIf-
-a-t-


T--
'- i-


4 r


1 i LLT


. i
~42 ~^ ~.


I' '


-~~-FtF~---C-L-CLC--' ' '-C--C-C' '-


CONFIDENTIAL


Fig. 3


i i.j








NACA CB No. L4H12


CONFIDENTIAL


I I


_ -_LLLJL-


- -. -
0 000
a 5J -

S : -.-- ---
o- O 00 1
,.l~ ~ 0 I 1 50' -- F

-- -- o -15 2 0o0' . ..
q- -_- --- 20.- 05'
--.
c -- r


t ---/- ---
-7
^j. -- -- ^ j ^ ^ ----t---- -------












1. II -
li --A t ,- - ,
-- - ^ -^ ? 1 -' ^^ -f ^ - - - -- i--- --






.-- L 4 ^ _i ^ L L .....L~ -s .. .,--A '-;. ._ _-. _.. _-.. ..


t_ Section angle of attack, 0, deg
.. _i.. L A i r I I -_-i_i .i _iL_-_ .-__.__,
Figure 4.- Lift characteristics of an NACA 654-421 airfoil section equipped
with sealed-gap 0.20c pLain aileron of true airfoil contour; R, 6 x 106
(approx.); test, TDT 615.

CONFIFETiTIAL


Fig. 4


7 -


4


I


J--t
Ij t-


I


I








i.-CA CB No. L4H12


o NACA 652-415

+ NACA 653-418

x NAcA 654-421


.0600


0
0
II
01





j-o .
o0




0

CO
I,


2o 1o.


1200


9 12 15 18 21
Airfoil thickness, percent chord


Airfoil thickness, percent chord


9 12 15 18 21
Airfoil thickness, percent chord CCNFIDENTIAL


Figure 5.- Variation of a (o and



So B with airfoil thickness for NACA 652-415,


653-418, and 654-421 airfoil sections equipped with
sealed-gap 0.20c plain ailerons of true airfoil
contour; R, 6 x 10 (approx.).


1'
'C. <''


CONFIDENTIAL


Fig. 5









NACA CB No. L4H12 Fig. 6



--71----


U / _- -






I I
-a a
N _o


zI




/ I r


Cek
| 0 4 *r
CM 4-3
\ 0




/ -

S4 o
I/ 00
aa

'; 0 43 0) 0
43l 4)
0

aC'I -
c; '0


S(0 I (I 1




2 0 00
I_ - 0 I -0 O H



1i i


rrx


0 0o




(T O [ Uf 1









NACA CB No. L4H12


u1 cu o o
'0 NO 0:d 0



o":F uT uoT08oe'Jp uojoae "'oqJ u om senp
'0ov '*u ToTJJ80oo J uoT oT'1.oe Jo .Uneme.zoi


> e


0

1 r



IC




*4
s s




.o oe




0 O i0
o to












o O'o o
o o


to g,4 o
4
N
'0








to
*q *

a 0
ur




0d
A 0
M o c p





* T (3



* E


Fig. 7









NACA CB No. L4H12 Fig. 8




,4








I-e-


4 '.
S o I 4 -
4 E
IL 0 cz





















fo o
Si o o
--- --- -- .- o t) H


V0 4





CO












Ir'
Cu



S t o




o o" s
-----------------------------------------------------~ ~





rd O


04 x
00
------- ----------------*J H







A 0__




o ,ueo eOO uo oe o me-
-^w ----


S.d 3
-_KL---------o -'

















'81 7 1UOTOTJ9oO i%.rr uojoea qo uge ooi






1
it








UNIVERSITY OF FLORIDA






'"'T. -- ... T" : A


I-'!LLE. FL 32611-7011 USA
G C,'ILE FL 132'1 -7,0 1i L, SA