Koenig, David G

English

NASA Technical Reports Server

‘vn --- ----; - 
wis+-- 
RESEARCH MEMORANDUM 
TESTS IN THE AMES 4U- BY 800FOOT WIND TUNNEL OF THE EFFECTS 
OF VARJOUS WING MODIFICATIONS ON THE LONGITUDINBL 
CHARACTERJSTICS OF TWO TRJKNGULARrWING 
AIRPLANE MODELS W!TH AND WITHOUT 
HORJZONTAL TAILS 
By David G. Koenig 
Ames Aeronautical Laboratory ’ 
CLASSIFICATION CEmegBt Fie’d’ caxfIf. 
https://ntrs.nasa.gov/search.jsp?R=19930088240 2020-06-17T07:47:10+00:00Z
1H 
NACA RM A54BO9 
NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS 
d 
RESEARCH MEMORANDUM 
TESTS IN TRE AMES 40- BY 80-FOOT WIND TUNNEL OF TEE EFFECTS 
OF VARIOUS WING MODIFICATIONS ON 'IRE LONGITUDINAL 
CHARACTERISTICS OF TWO TRIANGULAR-WING 
AIRPLAREMODELSWITRANDWTTHCUT 
HORIZONTAL TAIIS 
By David G. Koenig 
SUMMARY 
An investigation wae made with the obJective of emnating desta- 
bilizing changes of pitching moment through the use of ting modifications 
for two airplane models having triangular wings of aspect ratios 2 and 3. 
The models were tested with horizontal tails located above the extended 
wing chord plane as well as with the tails off. Chord extensions and 
fences, alone and in combination, were the principal wing modifications 
considered. The unfavorable stability changes through the lift ranges 
of the basic models were not entirely eliminated by the modifications 
tested. However, considerable improvement was obtafned for both models 
tith the use of a chord extension in combination tith a fence. 
INTRODUCTION 
For high-speed airplanes having horizontal tails, it has been found 
desirable for aerodynamic and structural reasons to place the tail above 
the extended wing-chord plane. However, for airplanes with low-aspect- 
ratio wings and with the tail above the wing chord plane, for certain 
tail lengths, destabilizing changes of pitching moment occur for portions 
of the lift range. This effect occurred for the two models reported in 
references 1 and 2, which were equipped with aspect ratio 2 and 3 tri- 
angularwings. An investigation was undertaken in the Ames 40- by 80- 
foot wind tunnel to study the possibility of reducing the destabilizing 
changes of pitching moment of these models through the use of wing modi- 
fications which included chord extensions, fences, and combinations of 
chord extensions and fences. 
2 NACA RM A+BOg 
. 
A secondary obJective of the investigation was that of improving the 
longitudfnal stability characteristics of the models with the horizontal 
tail removed. ; 
The complete range of wing modifications tested is shown in figure 1; 
however, only the results which indicate the general effectiveness of each 
type of wing modification are presented herein. A limited number of these 
modifications were used for the investigation with the horizontal tail 
off. 
- L 
NOTATION 
b 
bf 
bt 
C 
c 
CD 
CL 
Cm 
9 
S 
Sf 
St 
wing span, ft 
flap span (movable), ft 
hor%zontal-tail span, ft 
wing chord, measured parallel to ting center line, ft 
mean aerodynamic chord of wing, measured parallel to wing 
center 1iIEj 
cl' c2dy 
b/2 > f-t 
s, c dy 
drag coefficient, 9 
lift coeffictent, lift 
T 
pitching-moment coefficient, pitching moment qSF 
distance from moment center to pivot line of the horizontal 
tail, ft 
free-stream dynamic pressure, lb/sq ft 
total wing area, sq ft 
trailing-edge flap area (total movable), sq ft 
total horizontal-tail area, sq ft 
NACA RM A'+BOg *-- *'I# 
. 
X longitudinal coordinate parallel to the model plane of 
symmetry, ft 
Y lateral coordinate perpendfcular to the model plane of 
symmetry, f-t 
Z vertical coordinate perpendicular to the wing chord 
plane, ft 
a angle of attack of the wing chord plane with reference to 
free stream, deg 
Ef flap deflection with reference to the wing chord plane, deg 
7) 0 2x loo b 
Configuration Designation 
C midchord portion of fence 
EZ-Jm chord extension with chord extended 0.15~ and tith inboard 
end at q = 2 and with outboard end at q = m 
ES skewed chord extension 
(See fig. l(a).) 
F2,m fences at q = 2 and q =m on the tin@; placed parallel to model plane of symmetry 
LE modified leasing-edge radius 
-7 Ikueger ty-pe leading-edge flap with outboard end at q 
=2Jm spoiler on wing leadfng edge fn wing chord plane with 
inboard and outboard ends at q = 2 and m, respectively 
N noBe portion of fence 
RR wing with rounded-root plan form 
T rear portion of fence 
NACA RM A54BOg 
. 
MODELS 
The basic models used in this investigation are identical to the 
models used in the tests reported in references 1 and 2. The models 
with aspect ratio 2.and 3 wings will be referred to hereinafter as 
models A2 and A3, respectively. Drawings of the models are shown in 
figure 2 and pertinent geometric data are presented in table I. 
Airfoil sections of the wings parallel to the model plane of sym- 
metry were NACA 0005 sections modified with a straight line fairing 
from the 67-percent statton to the wing trailing edge. The wings were 
equipped with partial-span single-slotted flaps. 
The horizontal tails were installed at 0' incidence (with respect 
to the wing chord plane) on the vertical tail at 0.25 and 0.21 semispan 
above the wing chord plane for models A2 and 43, respectively. 
Details of the wing modifications investigated are presented in 
figure 3. The spanwise locations of the various ting modifications were 
set within an accuracy of O.O03b/2. Hereinafter each wing modification 
will be referred to by the notation indicated in figure 3 and defined 
in the section Notation. As indicated by figure 3(b), all fence lengths 
included in wing modifications for model A3 are thoee of 13, C, T when 
8f = 0' and N, C when Sf = 40°, For model A2, the fence lengths used 
on each wing modification for which resulta of tests are preBented 
herein are listed in table II. 
The major part of the investigation consisted of tests of the 
various ting modifications on the models with the horizontal tail 
installed and with the flaps undeflected. A few of the modifications 
were tested on the models with the horizontal tail off and flaps unde- 
fleeted, and with the horizontal tail on and flaps deflected. 
For all model configurations, force and moment data were obtained 
at O" sideslip through an angle-of-attack range of from -2O to 240. 
The Reynolds numbers of the tests were 14.6 and 12.8 million for models 
A2 and A3, respectively. The dynamic pressure was approximately 25 
pounds per square foot and the Mach number was 0.13 for both models. 
HACA RM A5&09 
RESULTS AND DISCUSSION 
Although all the wing modifications shown in figure 1 were inves- 
tigated, the results presented herein are limited to those which indi- 
cate the general effectiveness of each type of wing modification tested. 
Table III is an index to the basic aerodynamic data presented in figures 
4 through g. All pitching-moment data presented in figures 4, 5, 6, 
and 9 are referred to a moment center located at the quarter-chord sta- 
tion of the mean aerodynamic chord. The data were corrected for wind- 
tunnel effects and support-strut interference. 
Typical variations of dCm/dCL with CL for various types of wing 
modifications are presented in figure 10, for models with tail off and 
on. Since the stability changes due to wing modification were slight 
with the tail off as compared to those with the tail on, the effects of 
wing modification for the models with the tail on may be attributed to 
changes in the pitching-mament contribution of the horizontal tail. 
From figures 4 and 10 it may be seen that with the tail on, the 
most effective of the wing modifications tested did not completely elim- 
inate the reduced stability shown by the basic models at high lift coef- 
ficients. However, for the lift range from approximately CL = 0 to 
CL = 0.9, the destabilizing changes in dCm/dCL of 0.23 and 0.20 for 
the basic models A2 and A3, respectively, were decreased to approximately 
0.10 for both models by the most effective chord-extension fence combi- 
nations. These improvements in stability are also demonstrated in fig- 
ure ll in which are presented tail-on pitching-moment characteristics 
based on moment centers which produce a static margin of 0.06~ (at 
CL = 0). 
Ames Aeronautical Laboratory 
National Advisory Committee for Aeronautics 
Moffett Field, Calif., Feb. 9, 1954 
1. Graham, David, and Koenig, David G.: Tests in the Ames 40- by 
80-Foot Wind Tunnel of an Airplane Configuration With an 
Aspect Ratio 2 Triangular Wing and an All-Movable Horizontal 
Tail - Longitudinal Characteristics. NACA RM A5lB21, 1951. 
2. Koenig, David G.: Tests in the Ames 40- by 80-Foot Wind Tunnel 
of an Airplane Configuration With an Aspect Ratio 3 Triangular 
Wing and an All-Movable Horizontal Tail - Longitudinal and 
Lateral Characteristics. NACA RM A52L15, 1953. 
6 
TABlYE I.- GEOMETRIC DATA 
NACA RM A54B@J 
Wing Model A2 Model A3 
Area,sqft................. 312.50 
Span,ft . . . . . . . ...= . . . . . . . 25.00 'ii-:: 
Mean aerodynamic chord, ft . . . . . . . . . 16.67 13:65 
Aspect ratio . . . . . . . . . . . . . . . . 2.00 2.99 
Taper ratio . . . . . . . . . . . . . . . . l 0 0 
Airfoil section parallel to model center 
line . . . ..*............. NACACOO5 NACA 0005 
(modified) (modified) 
Fuselage 
Length,ft ................. 56.16 56.16 
Maximum diameter, f-t ............ 4.49 4.49 
Fineness ratio ............... 12.50 12.50 
Vertical tail 
Exposed area, aq ft . . . . . . . . . . . . . . 
Aspect ratio of plan f&a, extended to 
52=53 52.53 
model centerline . . . . . . . . . . . . . 1 1 
Taper ratio . . . . . . . . . . . . . , . . , . 0 0 
Airfoil section parallel to model center 
line . . . . . . . . . . . . . . . . . . . NACA 0005 NACA 0005 
(modified) (modified) 
Slotted, trailing-edge flaps 
Chord .................... 0.2084c 1.96 ft 
Sf/S (total movable} ............ 0.200 o.llg 
b-f/b (total movable) ............ 0.528 0.622 
Horizontal tail 
St/S ................. :-. . 0.200 0.199 
bt/b .................... 0.632 0.516 
2tE (for moment center at 0.25F) ...... 1.337 1.735 
Aspect ratio ................. 4.0 4.0 
Taper ratio ................. 0.50 0.50 
z/(b/2) ................... 0.25 0.21 
NACA RM A+BOg 
TABLE II.- MODEL A2 -FENCELENGTHSUSED 
FOR VARIOUS KNG MODIFICATIONS 
Fence Wfng 
lengths modification 
Horizontal 
tail 
~ F30; F40; F50; F30,50 
I F30,so %o+loot Fao 
I 
on and off 
On 
Off 
on 
on 
on 
0-n 
on 
on 
4:: 
4o” 
00 
O0 
O0 
O0 
O0 
4(a,b: 
t- 
4(c) 
A.2 
A3 
A2 
A3 
i22 
A3 
0 
0 
0 
4: 
!PABLF III." IND~ToBAsIcAER~cDA~ 
Wing modification 
Pitching-moment characteristics 
-+ 
L - . 
7(a) A2 
7(b) A3 
0 Off and on Basic; EEX+IOO; Fao,so; E503100, F40; RR; RR, Ism+so 
0 Off and on Basic; E4eoj Fz4,*; E4-, FS;?; LF,,; LE 
Drag characteristica 
Off and on haic; E5c+100; Fao,so; Eso+loo, F40; RR, mu, %~GTJO 
Off and ou Basic; E4-j F24,a E+w9 F& IJ'+sj I3 
on E4w100, Fao; Eswooj F40; Fao,so 
NACA RM A$BOg 9 
I 09 50 
b 
I 
/LQmy&..e”d f &oercy;o;dhmda’ 
Chord exf enslons 
fences 
7? 30,40,50 
I 
I 
I 
50 
b I 
h 
Sk8wed 
W/r/, LE. spd/BI 
Root rounding 
A/f chord exf8ns/ons, /5-percent extended chord. 
- 
Chord-extension -fence comb/notions 
(a) Model with aspect ratio 2 wing. 
Figure l.- The wing modifications investigated. 
10 
/S-percent extended ’ chord 
Chord extensions 
Sing/e ’ Double 
Fences Modified L.E 
I 
I 
I 
NACA RM A54Bw 
Chord-extension -fence c ombinations 
(b) Model with aspect ratio 3 wing. 
Figure l.- Concluded. 
c 
NACA FM A54BOg 11 
I 
I 
Model A2 
t 
Model A3 
Dimensions shown in feef 
unless ofberwise nofed 
=Q&z7 
Figure 2.- Geometric details of the basic models. 
12 -,. NACA RM A54BOg 
Mode/ A3, E40r80 
are Note: Except for ,& chord exfenshs 
designated as E&, iu’fi the Moati 
end af p I and the outboard end 
of +m. 
--I 4./7ff I- 
Model A2, Es 
Faired paru//e/ fo 
Profile of wing mo.ved 
forward u distance, x Typica/ secfion, pufu//e/ to 
mode/ plane of symmetry 
(a) Chord extensions. 
Ffgure 3.- Details of wing modifications investigated. 
NACA RM A5hBClS' 13 
S/of lip of TE. f/up 7 
n - =a consfunf 
’ fo 
e f 
7:E porfion, T = 
L.E porfion, N - 
Nofe: For mode/ A2, Nor T were removed 
for some configufufions. 
For mode/ A 3, a// fence configurutions 
wifh 8~ 00 inchded Ai, C., uf~d 7: 
For bofh mode/s, &f= 40 “I T wus removed. 
For both models, Fz of F~,,indicates 
fences uf 7 =I or 7s 2 und m. 
(b) Fencee. 
Figure 3.- Contfnued- 
14 NACA RM A$BOg 
center /he 
0.6 
Or-dinofe, 
ff .2 
0 
I I I I 
0 .2 .4 .6 .8 10 
xl?, ff 
Sect/on A-A 
L.E s~oi/er. Sect/on perpendicuhr to 
busic wing L. E 
Section 6 -B 
-L.ER, o.o/ 
of basic 
wing chord 
(c) Root rounding and spoiler detaili -for model A2. 
Figure 3.- Continued. 
NACA RM A54BOg b 15 
Cenfer of L.E. ufc of 
fee-stream section 7 
Secfian A-A 
Fairs info busic 
This secfion is fypicaf for wing 
Ypper 
-0.49 
./I 
.60 
BUSiC 
wing 
I 
L owef 
-0.49 
d.06 
4.48 
J-48 
-1.45 
4.49 
-1.64 
-/.80 secfions pafdef fo mode/ p/une of 
symme fry from fusefuge fo g-40. 
1 8.001 
Ffom 4=40 fo 7 =50, L.E rudius reduces Dimensions &own 
fo fhaf of basic wing secfion. In percent chord 
v 
Modified L-E: 
(a) Details of leading-edge flap and modified wing leading edge for 
modelM. 
Figure 3 .- Concluded. 
I I III III II II I Ill I I I II’1 
I i 11 1 iii I I ii II I i i i i I i i I 
l2- I I I I I I I I I I I I I I I I I I I I l I I I 
II 
-+ + 
I I I I 
LO. 
Y78 .w 8 8 is 8 -.04 49 y/2 -.I6 90 524 ~28 
Cm s! 
(a) MdelA2; wing mcdlflcatione, E and F. 
2 
Figure 4.- Pitching-manent characteristics of the model.a with the flaps undeflected; 
horizontal tail on. 8i 
.8 ’ ’ ” ’ ’ ’ ’ 
(b) Model A2; wing mcdifications, E, I?, and RR. 
Figure 4.- Continued. 
P 
co 
8 09 -.04 -.#? -.I.? -.I6 -20 
Cm 
(c) Moael A3; all ting modifications. 
Figure 4. - conchaea. 
. 
.8 
I I I I I I I IA Ii7 1-Y I I I/I I4 I I I 
Cm 
(a) ModelA2. 
Bigure 5.- PitchFng-moment characteristic6 of the moclels with the flaps undeflected; 
horizontal tail off. 
. . 
.6 
i 5 -.w 43 -.I2 
Cm 
(b) Model A3. 
Figure 5.- Concluded. 
I 
l . 
Cm 
figure 6.- Pitching-moment characteristics of the modele tith flaps deflected kO"; 
horizontal tail on. 
.8 
.6 
.4 
21 
I 
. 
0 
-.2 i 
-4 
I I I I I I I I I I I I I I I I I I I I 
0 0 0 4 8 12 I6 
a 
(a) Model A2. 
Figure 7.- Lift characteristics of the noaels with the flaps undeflected. 
. . . 
/4 
I.0 
.8 
.6 
.4 
.2 
0 
-.2 
-4 4 8 12 16 20 24 e23 
ca 
(b) ModelA3. 
Figure 7.- Concluaea. 
12 
+ 
.I2 .I6 
CD 
--I 
(a) Model A2. 
Figure 8.- Drag characteristics of the models with the flaps undeflected. 
. I I , 
.- 
* I 
, 4 
.8 
CD 
(b) lkdel A3. 
figure 8. - concuded. 
00 A0 
0 0 .I .2 .3 
. 
Cm 
Figure 9.- Effect of fence length on the characteristics of model 42 
with horizontal tail on; 6f = 0'. 
0 I , 
NACA RM A54EO9 27 
I.2 
.8 
.4 
0 
I.2 
.B 
.4 
0 
0 4 52 0.3 0.4 0 4 -.2 -.3 -4 
I.2 
c, - 
M 
i-2 /. 2. I 
.8 - .8 - . 
 
 
.4 
0 
 - .4 - 
o- ’ 
I I 0 0 I I  
0 -./ ./ 72 -.3 74 0 -.I 72 0.3 -.4 
Gm 
--TgGig~~ 
7q 
(a) Model A2. ) 
7 
0 -.2 -.3 -.4 0 -./ 0.2 -. 3 -.4 
Figure lO.- The variation of dCm/dC~ with lift coefficient for various 
ting mcdificatione. 
28 NACA FtM A54BO9 
.8 
.4 
0 
-0 -J 72 0.3 0.4 
0 -./ 72 -.3 74 
(b) Model A3. 
Figure lo.- Concluded. 
a8 
CL 
.6 
.8 
CL 
.6 
-.2 
./6 .I2 .08 m 0 -04 
Cm 
-.2- 
.08 04 0 44 48 -.I2 -.I6 
Cm 
(a) Mel A2. (b) MlelA3. 
Figure IL- Effect on the pitching-mmen t characterlstice of the mcdele of a chord extension 
In combination with a fence; ac&c 
LL(cL4 
= -atic'; hor3.eorltal tail on. 


Tests in the Ames 40- by 80-foot wind tunnel of the effects of varying wing modifications on the longitudinal characteristics of two-triangular wing airplane models with and without horizontal tails

Tests in the Ames 40- by 80-foot wind tunnel of the effects of varying wing modifications on the longitudinal characteristics of two-triangular wing airplane models with and without horizontal tails

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server