Scale and turbulence effects on the lift and drag characteristics of the NACA 65₃-418, a = 1.0 airfoil section

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Material Information

Title:
Scale and turbulence effects on the lift and drag characteristics of the NACA 65₃-418, a = 1.0 airfoil section
Alternate Title:
NACA wartime reports
Physical Description:
9, 13 p. : ; 28 cm.
Language:
English
Creator:
Quinn, John H
Tucker, Warren A
Langley Aeronautical Laboratory
United States -- National Advisory Committee for Aeronautics
Publisher:
Langley Memorial Aeronautical Laboratory
Place of Publication:
Langley Field, VA
Publication Date:

Subjects

Subjects / Keywords:
Reynolds number   ( lcsh )
Aerofoils   ( lcsh )
Aerodynamics -- Research   ( lcsh )
Genre:
federal government publication   ( marcgt )
bibliography   ( marcgt )
technical report   ( marcgt )
non-fiction   ( marcgt )

Notes

Summary:
Summary: An investigation in two NACA wind tunnels has determined the effect of Reynolds number and stream turbulence on the lift and drag characteristics of a low-drag airfoil, the NACA 65₃-418, a=1.0 section, particularly at low Reynolds numbers, to give an indication of the performance of low-drag wings in low-scale tests. The results are correlated with similar data for the same airfoil section in the NACA two-dimensional low-turbulence pressure tunnel to provide data over a range of Reynolds number from 0.19 to 9.0 x 10⁶. Large increases in minimum drag coefficient were found as the Reynolds number decreased. This effect was particularly marked at Reynolds numbers below 1.5 x 10⁶. At Reynolds numbers below 1.5 x 10⁶, stream turbulence had little effect on the drag characteristics of the NACA 65₃-418 airfoil section when compared on the basis of test Reynolds number but, at higher Reynolds numbers, stream turbulence had a detrimental effect on drag. Large decreases in maximum lift coefficient were found with decreasing Reynolds number; most of this decrease was encountered at Reynolds numbers above 2.0 x 10⁶. Marked differences in maximum lift were apparent between the results obtained at high and low turbulence. When compared on the basis of effective Reynolds number, however, fair agreement was reached between the data obtained under both turbulence conditions.
Bibliography:
Includes bibliographic references (p. 8).
Statement of Responsibility:
by John H. Quinn, Jr., and Warren A. Tucker.
General Note:
"Report no. L-138."
General Note:
"Originally issued August 1944 as Advance Confidential Report L4H11."
General Note:
"Report date August 1944."
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 applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 003605349
oclc - 71123894
System ID:
AA00009422:00001

Full Text

ACR No. L4H E




NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS





lWAlR'TIME RE PORT
ORIGINALLY ISSUED
August 1944 as
Advance Confidential Report LHEll

SCALE AND TURBULENCE EFFECTS ON THE LIFT
AND DRAG CHARACTERISTICS OF THE
NACA 653-418, a = 1.0 AIRFOIL SECTION
By John H. Quinn, Jr., and Warren A. Tucker

Langley Memorial Aeronautical Laboratory
Langley Field, Va.


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-
vlously4held under a security status but are now unclassified. Some of these reports were not tech-
Snically edited. All have been reproduced without change in order to expedite general distribution.
L 138
DOCUMENTS DEPARTMENT





































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/scaleturbulencee001ang




-I / -



.lACA ACR io., r4H111

IJATIOIAL ADVISORY COIMTTTEE FOR AERONAUTICS


ADVANCE COI,7IDEIITIAL REPORT


SCALE AND TURBULENCE EFFECT'. 01.1 THE LIFT

AITD DIRA CHARACTERISTICS OF THE

HACA 653-L.-1, a = 1.0 AIRiFOIL SECTION

By John H. >uinn, Jr. and. Y.arren r.. Tucker


S tUI.T A R Y


An investizatic.n in two IACA wind tunnels has decer-
mined the effect of Re;,T ol,.:-- nuLi'.)oer ad stream turbulence
on the lift and drag characteristics of a low-dr.g air-
foil, the HCA 6- 1, a = 1.0 section, particularly
at low .Re-:nolds numbers, to give an indication of tha
Performance of low-drag wings ifn low-scale tests. The
results are correlated with similar data for the same
airfoil section in the IIACA two-dimensional low-turbulence
nressuire tiutel to provide da4a over a range of Re"-nclds
n. ouTber from 0.10 to 9.0 x 100.

Large increases in minimum. drag coefficieni-t .v-Ere
found -as the Reynolds number decreased. This effect was
particularl.- marked at Reynolds numbers below 1.5 x 106.
At Rerynolds numbers below 1.5 x 10 stream turbulence had
little effect on the drag characteristics of the
HACA 657-4.19 airfoil section when compared on the basis
of test Re.ynolds nu.-ribev- but, at higher Re,'nolds numbers,
stream turbulence had a detrimental effect on drag.
Large decreases in maximum lift coefficient were
found with decreasing Reynolds number; most uf this
decrease was encountered at Reynolds numbers above
2.0 x 10'. Marked differences in maximum lift were
apparent between the results obtained at high and low
turbulence. Vfhen compared on the basis of effective
Reynolds number, however, fair agreement was reached
between the data obtained under both turbulence condi-
tions.








2 CONFIDENTIAL NACA ACR No. i)H11


Considerable variation of lift-curve slope with
Reynolds number was found. Results at low and high
turbulence differed as much as 6 percent but yielded
the same value of lift-curve slope at a Reynolds number
of approximately .0O x 10 At Reynolds numbers higher
than 4.0 x 100, no scale effect on the lift-curve slope
was observed over the range tested.

In view of the large variations in the lift and
drag characteristics found for the NACA 65 -Ii18 airfoil
section over a range of Reynolds number from 0.19
to 9.0 x 10 it is thought that the use of low Reynolds
number test data relating to low-drag airfoils is
unreliable either to estimate full-scale characteristics
or to determine the relative merits of airfoil sections
at higher Reynolds numbers.


INTRODUCTION


Investigations of scale effect on the lift and drag
characteristics of low-drag airfoil sections have regu-
larly been made at Reynolds numbers above 3.0 x 100
and at low stream turbulence in the NACA two-dimensional
low-turbulence pressure tunnel (designated TDT). It is
well known that other invest --tions of low-drag-airfoil
characteristics are carried out in tunnels with higher
turbulence levels at lower Reynolds numbers than the
investigations in the TDT. Proper interpretation of
these data obtained at lower' Reynolds numbers and at
various degrees of stream turbulence is difficult because
of the unknown stream turbulence effect and scale effect
at low Reynolds numbers on the characteristics of low-drag
airfoils. Extrapolation of thes3 data to higher Reynolds
numbers and low turbulence (flight conditions) is
unreliable for this reason.

The purpose of the present investigation was to
determine the effect of Reynolds number and stream
turbulence on the lift and droj characteristics of a
low-dr-, airfoil section through a range of Reynolds
number below 5.0 x 106. Models of the UaCA 65 -1l8,a= 1.0
airfoil section having chords of 6 and 2). inches were
tested in the NACA twro-dimensional low-turbulence tunnel
(designated LTT), which has a stream turbulence of only a


CONFIDENT TRIAL







TA.CA .CR IT.-,. 1411 COTTFIDEi7TIAL 7


-" -''.:n-':r- td.ths of 1 pr-rc nt lThii tii.rIbul.-nce is c*onr-'- i. -
"':*." l,, o.' the le'el a1 t .';ic'h an-; chn e would be noticee-
r e :- t i Re;nold. n ifber o01 -, s. ier- r'
-. ':- .-. r:-'or._..? of Fe-"nold '. iLu be- r' f'rc 77
'- ., 0'". cd.ls of t'ic sDIie section having 1 -h Dor c 's
S ... :,J L in es wer E t ested- i-, the L..-.L 7- *, 1.,i,- ..
-, (': ? ated 7 b'y 10 tin 'l ) wi hich h s a, thrS Lr ". .".
.t.'.r of 1. a detr.iined fro.- thh.a're tests. 'The test
: --1 i-i 1 : b r-s- from 2'. to 0 -. .< 1C ,


i ODE LS Ali] ,',"'D3


Oirrr n.ts for the I'" '.-. -, 9 = 1. 0 -.ir ,oil
.ection i a-r: -.r. sent-edr in t,-ble I. The ,i o,':],- ha' -i-g
icr i. cf ,'L ,', ., ,:. n s .* 1 -: :...n .- :tru .--
tion ar f'L e ,_eor ti : -, '>ti,,- The thors 1:-,'.1:. d
in. r: eerei-er? 1. Thle c-in: o--chord -c:le1 ''zs b iit cf '-.1 :1
_i I:'. '>i alic"' -"'v :a rol .'i-"J b, ;.. '!-]- to -,.:v ,n -.i'",-
d. -n a .".:. 11 r 1,c,:t -u f1 ..

q i-- n l'i.-cho,'d micdei.1 :' I' t. e td f' n.: 1 ,u pr' -
.;:e. c.1 r, nrd .troshere the '.T;'1 t FR ;,- m Cl.
nu:nb:-l o'- .77, .1, :.. s a d i10 The jT,-
,ode.. l ov*v-: t^ .. te.; t s- r i .i *,r.e '.'-i T. he L ..7T -
'..'-.-,: ,'!-,.: nu'rb:r.: from 0'.c f. to 2. x IC The -i- nci-
chor' ..:'.cdel was -!m1 ilar ly teo ted in i-th L'T. for a range
t -. -ol numb-er fr-or,. C'. to '* L.. 10 -id in
th iD'T foor. a range from 0.. t .0 C. '.

a t: e TDT and L'I', drag '.us me isuL-red b- the v, ake-
sur- e:v methodd ar d. lift w.s ac' raie.Cd -, int-er-rat ,i": th='
,-'re- ...s -Zlonr the floor -and ce,-i. i the tun.i--l tst
sec'c ea-'- use the TDr acinr LT r' have test sections ''i
thin 2:,. e .e, the tune l-wall .corre cc ions to lift and
'i --. for ea-ich rno:lel were t he sa. ie i:n oth tunnels T'e
,.:r.el-w ll orr.e cti on' f or- the '-in.jC -cho.rd riod el v;'re
o''t -d from the same basi c'n. ziJ'r-at ion- that *:er
u':ed t determine the .crrecti.;on LC the ;..-inch-chord


tn the 7 by 10 tunnel, the ',. -ls s.ua nne.'d the test
section except for a .small iearanc'e at each end. They
'.'.re ".-i 'd1- attached to thle baltnce fra e l :, tori-:ue tubes


COIFITDEIT'IAL






I.ACA ACR No- L1.H11


extending through the tunnel walls. This installation
is thought to approximate closely twvo-dimensional flow
and therefore to make it possible to obtain section
characteristics.

In the 7 by 10 tunnel, lift characteristics were
obtained from force measurements on the tunnel balance
system. Drag characteristics were obtained by the wake-
survey method. Lift coefficients have been corrected
for effects of tunnel-wall interference by using the
experimental correction explained in reference 2. The
drag coefficients were corrected for tunnel-wall inter-
ference by using the same considerations from which the
corrections were obtained for the TDT and LTT data-


TRZTLTS AND DISCUSSICA


A ccmrarison of lift data obtained in the LTT and
TDT at a Reynolds number R of 2.77 x 106 is presented
in figure 1. The LTT data were obtained at atmospheric
pressure and a Mlach number of 0.1?L, whereas the T'." data
2
were obtained at a tunnel pressure of 1 atmospheres and
a '.ach number of 0.150. ThV curves are in good agreement
both in respect to slope and maximum lift coefficient; it
is therefore improbable that any ."ach number effect on
maximum lift coefficient, which m it have been expected
from the results presented in reference 5, exists in the
LTT data at this Reynolds number.

Lift data from the LTT and TDT are presented in
figures 2 to 4 and from the 7 by 10 tunnel, in figure 5.
It may be noted in figure 4 that tests of the 6-inch-chord
and 24-inch-chord models in the LTT at Reynolds numbers
of 0.66 and 0.68 x 106, respectively, are in good agree-
ment.

At values of the lift coefficient above 0.9, a jog
in the lift curve (figs. 2 to 4) is encountered. This
jog is due to a region of laminar separation on the upoer
surface just downstream of the leading edge. The jog
becomes more marked as the Reynolds number decreases and,
at the lowest Reynolds number, the jog in effect determines
maximum lift. It may be seen in figure 5 that no jog in the
lift curve is found in the results from the 7 by 10 tunnel.
CONFIDENTIAL


COFFI TDETIAL








tIACA ACR ITo. LHi{ll CONFIDENTIAL 5


The absence of the jog rin these curves indicates that,
at the point. on the airfoil where laminar separation
occurs in the LTT, the flow is already turbulent in the
7 by 10 tunnel because of the high turbulence lev,-l.
A detailed investigation of this separation effect is
reported in reference 1!.

Dr-ag data are presented in figures 6 and 7. It may
be nnted in figure t that the extent of the low-dr:ag ran-ge
increases progressively as the Feynolds number is decreased.
The high values of the drag coefficients at low Reynolds
nunl.ers sppFar to be connected with a region of laminar
separation just downstream of the point of minimum c:res-
sure. Little is known of the laws governing the e:-xtent
and quantitative effect of this local region of separated
flow except that both ths extent of the region and the
drag increase as the Reynolis3 number is decreased.

It may be noted in figure 7 that, for the higher
test Reynolds numbers, minimum dra.' occurs in the 7 by
10 tunnel at a lift coefficient of about 0.5 instead
of at the design lift coefficient of O.h.. Because of the
difficulty of nreasuring drag by the wake -survey method
in the 7 by 10 tunnel, drag data were obtained for only
a limited range of lift coefficient.

Curves that show the scale effect on rmaxirLum lift
coefficient are presented in figure '. The test results
from the 7 by 10 tunnel are plotted against both test and
effective Pe7nold3- number r. (ffecti ve Reynolds numbn er -
Test tevnol,ds number x Turbulence factor.) The LTT
and TDT results are plotted against the test Reynolds
number vhi.ch, of course, would be equal to the effective
Reynrolds number since the stream turbulence is only a
few hundredths of 1 percent. Large decreases in maximum
lift coefficient are apparent with decreasing Reynolds
number, particularly above an effective Reynolds number
of 2.0 > 100., Figure S indicates that, below a Reynolds
nn-umber of 100, the data from the 7 by 10 tunnel are in
fair agreement w'i th the data fromr, the TDT and LTT when
plotted against test Reynolds number. Above a Reynolds
number of 100, the data from the 7 by 10 tunnel are in
good agreement with the data from the TDT and LTT when
1StLted against effective Reynolds number, It is seen
that the- rate of increase in max-.imunr lift coefficient is,
greatest at a Peynolds number of approximately 5.0 x 106,
r'or other low-drag airfoils, neither the value of the
Reynolds number at which this rapid increase takes place
nor its quantitative effect is known. It is therefore
thought that extrapolation of low-scale data or data which
do not determine this characteristic should be avoided.
CO NFIDENTI AL







NACA ACR No. L41HII


Various curves of drag coefficient against Reynolds
number are presented in figure 9. The results obtained
for the NACA 657-418 section in the LTT and TDT show that
for this airfoil the drag does not follow the law for the
variation of either laminar or turbulent skin friction
over a flat plate. T1,ir Ium drag coefficient increases
progressively as Reynolds number ir~ases; this effect
is particularly marked at Reynolds numbers below
1.5 x 106.
r
At Reynolds numbers below 1,5 x 10, LTT and TDT
results are in fair agreement witn results from the
7 by 10 tunnel when compared on the basis of test
Reynolds number. At a Reynolds number of about 1.5 x 106,
at which local separation effects are dcreasin and
reasonably low drag is found on the HACA 65 -41i section
in the LTT and ITT ', the results from the 7 by 10 tunnel
as plotted against Res Reynolds n-umber are starting to
diverge from the LT n res' t. As the Rernolds
number i>coscs the K It a e level of the
7 by 10 tumrjno r-c-es th i ra a. tio)n point toward the
leading edge ar.d icreases the drag over the values
obtained in streams of low turbulence.

A curve of dr,-" coefficient at the design lift coef-
ficient for the i. CA 0012 '-:. fcil section is presented in
figure 9 for comi,)jrison. This curve represents the
average of several rest results in the LTT. It may be
noted that, at Reynolds numbers below 1.5 x 106, the lcw-
drag section no longer shows a lower drag than the con-
ventional section.

Scale effect on lift-curve slope and on the angle
of zero lift is shown in figure 10. Data obtained in the
LTT at Reynolds numbers of 0.96 and 1.57 x 106 are not
presentaii since sufficient data were not taken to define
the slooe accurately. Although the scale effect on the
angle of zero lift is small, considerable variation of
lift-curve slope with Reynolds number is found. In the
Reynolds number range from 0.20 to 53.0 x 106, there is
at first a divergence and then a convergence of the data
obtained under the two turbulence conliticns; the maximum
difference between the two curves is apprc:.: -itely 6 per-
cent at Reynolds numbersof approximately 10 At Reynolds


CONFIDENTIAL


CO:FI DEITTAL









'TA .CR U7.-o Lr-l 111


ni -,ers above ID.0 x 106, the slopes appear to be the S. .?
*under the different turbulence conditions, and their'
seems to be no further scale effect for the range tested.
at a Reynolds numibeir of aoproxiimstely 10, it may be
- s, red that the variation of lift-curv\- sloo-e with
F.e ynolds number becomes small under the high-tu.rbulence
condition. It seTims reasonable to e-pect. ho ever, that
the Re:nolds number above which the changes in lift-
curve slooe becor'e unimoortant depends considerably on
tht particular airfoil section ard turbulence character-
istics or the air stream. The data presented in fig-
ure 10 further emphasize the unreliability of using data
at low Re-Tolds numbers to predict full-scale chisrater-
i s t i s


COIfCLUTDIIHG REM':LRKS


Large increase in minimrui dra.Q coefficient were
founCi as the e'.n-olds number decreased ; this effect was
particularly r .i.arked i. t Re nclds numbers belcw 1.5 x 10 .
At Reynolds numbers below 1.5 x 100, stream turbulence
had little. effect on the drag ch.&racteri stics of the
FIkA 655-'41 a = 1.0 airfoil section when compared on
the basis of test Reynolds nur'iber but, at higher Re:,nold3
numbers, stream turbulence had a detrimental effect on
. rag.

Large decreases in maximuia lift coefficient were
found with decreasing Reynolds ninumber; most of this
necre.ase was encountered at Reynolds numbers above
2.0 x 100. Marked J.ifferences in maximujn lift were
apc-arent between the results obtained at high and low
turbulence. When compared on the basis of effective
Reynolds number, however, fair agreement was reached
between the data obtained under both turbulence condi-
tions.

Considerable variation of lift-curve slope with
Reynolds number was found. Results at low and high
turbulence differed by as much as 6 percent but yielded
the same value of lift-curve slope at a Reynolds number
cf approximately 4.0 x 106'. At Reynolds numbers higher
than 4.0 ) 100, no scale effect on the lift-curve slope
was observed over the range tested.
COTFIDE'HTT LL


COITFIDETIAL









NACA ACR No. ILH11


in view of the large e variation in the lift and drag
characteristics fomnd for the 1LACA 655-)..18 airfoil
section over a ranre of Reynolds number from 0.19 to
9.0 x 10 it is felt that the use of low Reynolds number
test data relating to low-drag airfoils is unreliable
either to estimate full-scale characteristics or to
determine the relative merits of airfoil sections at
higher Reynolds numbers.


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





-F-ZR'CES


1. Jacobs, :--tman N., Abbott, Ira F., and Davidson,
SMilton. Preliminary Low-LDrig-Airfoil and Flap
Data from Tests at Large Reynolds Numbers and
Low Turbulence, and Supplement, YACA ACR,
March q192.

2. Wenzinger, Carl J., and Harris, Thomas A.: Wind-
Tunnel Investigation of an '..C.A. 25012 Airfoil
with Various Arrangements of Slotted Flaps.
NACA Peep. No. 661I, 1959.

3. Stack, John, 7:ii uk, Henry A., and Cleary, Harold E.:
Preliminary Investigation of the Tffect of Com-
pressibility on the Maximum Lift Coefficient.
NACA ACR7, Feb. 1945.

4. von Doenhoff, Albert E., and T-tervin, Neil: Investi-
gation of the Variation of Lift Coefficient with
Reynolds Number at a Ivioderate Angle of Attack on
a Low-Drag Airfoil. NACA CB, Nov. 19.2.


CONFIDENTIAL


COfrPIDEl.TI AL







L.CA AC? I". rJ rH 1
I.. ,- I T I I


Ti.LE- I

, -D AT .?:r T'T- -AC C i.c, a = 1.. A;IRF IL S-CTI9

ll szt--tions an,. or:linates givenn in ;:e-rent ohord

',O'-er suri'fi.ce Lo'?.er si.urface

3:ation I OCl: int--e SacJ cn O'rcd.na se

0 0 "3 -
.27,. 1. ,o .712 -1.213
,5 5 1 .72 "c7 -1 'i
.'7,. 2j.2c 1. '7 -1.7 01
2.1,:i1 5.10- 2.,19 .56o0
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7.123 ., ) 7.. 77 -4. ,70
S.61, 6..4i, l0.5,l .L lo
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19 .671 I ? .0 ,,! 2 ,2 9 ,.. ,7I
2. .716 1 9.i1 a .2;5 -o.5 ,
o. 7 3 10. C 50.2;,2 -('.61n
"'. 1.1 50P.11. -_._ '2
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1 .7i 1 77.' 3 .'. -1.572


a I


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L.0.1 1 .1i,8 5I.9_9 -5.-14
0.0 .4+o Sq10 C6 .12




.. is i o f. tirnu end of'-
SO. 1.j 7 %1o "69 ^.IC 11,d
7j,.1 i .15 7 .TOA6 -2.AT I5,
C0.1- 7 .2 T?.-, P -1.7A5

90-" 9q2 2.5S0 .0It.Q' -.282
95. +I I 1.12 i 0 9L. .11
I'-.-000 1 0 100. C,0 0,

L.E. rea-lins: 1.96. Slope of ra.,:dius thrTulh end of
i chord;: ,.1.!0 .



NA"ITOTAL ADVISORY
CO,', I"-..-n ._ FP _, AE.O.IA.TICI S


T0 FTTDEVTIAL


COJFTIDE.TITAL.







IJACA ACR NC. L4H11


Tunnel Tunnel pressure Mach
1.6 (atm) number
o LTT 1 0.194
+ TDT .150
3






r-
t -



4 .4
I /



0

-.4
r--I--


-1.24
-24


Section angle of attack, ao,


NATIONAL ADVISORY
COMMITTEE FOR AERONAUTICS


deg


Figure 1 .- Lift characteristics of 24-inch-chord model of NACA 655-l18,
a = 1.0 airfoil section in NACA two-dimensional low-turbulence tunnel
(designated LTT) and NACA two-dimensional low-turbulence pressure
tunnel (designated TDT). R = 2.77 x 106. COIiFIDFIJTIAL


CO.NF IDENTIAL


FIG. 1








NACA ACP NO. L4H11



1.8 I


COIIFI DFNT IAL


Sercion single of0 struck, o,, deg


CONFIDENTIAL


(a) Model having 6-Inch chord in LTT.
Figure 2 .- Lift characteristics of the NAC4 65,-L18 airfoil section.


FIG. 2a








;JACA ACR NO. L4H11


CONF IDENTICAL


-d -L h .
,-. t ij..- a pi e af att ., E.1, qa

'oI Model having -a-Inch chord In LTT.
P1F ure 2 .- Continued.


12 16 zo



CChF IFEIJNTIAL


PIG. 2b








NfACA ACR [10. L4 H 1


CO F I DENJTIAL


FIG. 2c


-8 -4 0 4 8 12 16 20
SectIc.n a ngl of atct.cK, 3o, dtg

CONFIDENTIAL
(c) Moael having 2l-lnch chord In TDT.
Flsrure 2 .- Concluded.


1.L




1.2




1.0




.8

I,












.2




0
-.2
4-2








[iACA ACFP I1 L4H11


CONJF IEllITIAL


-8 -L 0 4 8 12
Angle of attack, ao, deg

P1gure 3 .- Lift characteristics of the NACA 6534-i8 alrfo11
action; 6-inch-chord model In TDT.

COl F IDF ETIAL


FIG. 7


.8





.4



.6


0





-.2
-.


16 20







rJACA ACR N'iO. L4H11


12 16 20


Angle of attack, o deg


CONFIDENTIAL


Flaure 3 .- Concluded.


COJF'IDEDT TIAL


FIG. 2 .,









IJACA ACR iJO. L4H11


iff, rn i


In. I


S '. x ,
.'I: J t. LIT


CONFIDENTIAL


Ft gLre 4 .- Ll f .n: rir c .erL tic: of tr.. N. iT A r't -l 8 r rl.:.l ;; t i 7 .:. r, rcr. rr ugr, tre retire
r r.ng of F '.n-, i.1 s.3 'r.r i ,r.F rer .


1.ec .r. arngi" .:.' arirtacl%, 30, a)ig


CONFIDENTIAL


FIG. 4








IJACA ACP. NO. L4H11




1.8


CON F IDEITIAL


CO H P I DE T IA L


Section angle of attack, co, aeg


Figure 5.- Lift craracterl3tLcs of tre UICA 653-18 alrrCll seeelran
in trne LMIAL 7- b7 10-foot turrnel ideslgnasd 7 oy 10 tunnell.


FIG. 5


Modal







NJACA ACR NO. L4H11


.032





.028


.024


.020




.016





.012





.008


.004


Section lift coefficient, cL
CONFIDENTIAL

Figure 6.- Drag characteristics of the NACA 653-418 airfoil section in
the LTT and TDT.


CONFIDEN TRIAL


FIG. 6







NACA ACR NiO. L4H11


Model


+ 0.19
o .57
.56
a .75
*v .75
Z 1.50
0 2.2.L
> 2.99


.020


.016




.012


.008




.004


x 10


12-inch chbrd


48-inch chord


Section lift coefficient, c,


CONFIDENTIAL


Figure 7 .- Drag characteristics of the MACA 653-418 airfoil section
in the 7 by 10 tunnel.


CONFIDENTIAL


FIG. 7








NACA ACR NO. L4H11 FIG. 8




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NACA ACR NO. L4H11 FIG. 9








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NACA ACR NO. L4H11 FIG. 10




IO
0
,-
x

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o :





00.0 4 5
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UNIVERSITY OF FLORIDA
I I I I ll IIIIIII IIIII
3 1262 08103 273 1



UNIVERSITY OF FLORIDA
DOCUMENTS DEPARTMENT
120 MARSTON SCIENCE LIBRARY
PRO. BOX 117011
GAINESVILLE, FL 32611-7011 USA












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