•
Gil
RO S
REPORT OS
YlIND TUNNEL TESTS
ON
G-Z AIRSHIP MODEL 6R012S
VJITH PROTUBERANCES
by
DANIRL GUGGENHEIM AIRSHIP I NSTITUTE
AKRON, OHIO
J anuary S, l9S4
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Page
1
1
2
2
2
3-4
5
TABLE OF CONTENTS
Introduction
Summary
Apparatus and Suspen~ion of Model
Calibration
Teat Procedure
Sketches of Model Suspension and Spoil ers
Photorraphs of ?fodel Suspended at 50 Pitch
Test Results
Data. Sheets
Con~lusions
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D
FL
RI
q
CB
K
L
SYMBOLS
Drag force of model in direction of wind tunnel
jet axis - mm preaeure he d.
Lift force ncting on front fitting of model in
direction normal to wind tunnel jet axis - mm pr eesure
head.
Lift force noting on rear fitting of model in direction
normal to wind tunnel jet nxie - mm pressure head.
Velocity head of '\vind tunnel jet (See page 3)
Center of buoyancy of model.
Distance of CB from bow fi ttin1~ on :model.
Distance of CB from stern fitting on model.
Other symbols are given on p~ges 5-4.
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INTRODUCTION
Page 1
In order to determine the effect of a protuberance on the pitching
moment of an airship when placed on the airship's surface in the
region of the bow, the Goodyear-Zeppelin Corporation requested wind
tunnel test~ to be made for them by the Daniel Guggenheim Airship
Institute. The reeults of this investigation, covered by G-Z test
specification R-33-10, are given in this report.
The proposed test specification R-33-10 is as f ollowss
R-33-10: "This test is to consist of standard three component
mee~urement~ of a 4 foot conventional air~hip model
supplied by us. It is of wood, solid, and has detachable
fins. The model bears our number 6R0123. The
3 component mea~urementc are to comprise angles of
pitch of approximately -so, _30, oo, +30, +Go, +90,
+120, eaoh at say 4 different speed~ (perhape 50,
70 , 90 , 110 mph). The te~t i~ to be repeated in the
follov~ng conditions of the model: a) without fins,
b) with standard fins, c), d), e), f), g), h) vnth
small protrusions in the bow region in various po~itions.
The protrusions have been prepared by us.
Only one of the tests tmder c) to h) will be extended
over the whole range of angl es of pitch nnd speed.
The otherr 'rleed be tested only under oo, 30, and so
pitoh and for two epeeds only (say 70 and 110 mph).
"If the movement to obtain differ ent angles of pitch
is complicated, it may be feasible to try any one sngle
with various protrusion positions firEt.
"The moment is the mo.:!t important measurement, more
important than drag and lift. A wire suspension tare
test is desirable for zero And. so angle, but ~ot necessary
to be exceedingly accurate. This test can be
begun any time now."
SUMMARY
The effectiveness of the protuberance was found to be negligible
for oo and 120 pitch of the model, eo that further investigation
was not considered worthwhile .
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APPARATUS
Page 2
D SUSP SlON OF MODEL
The model was tested in the vertical wind tunnel of the Doniel
Guggel'.lheim Airsl1ip Institute. 1 Suoponeion fittings, shown in
sketch #2, were attaohed to the bow and stern of the mode1,
and tl1e model wna hung in the tunnel as shown in eketch # 1 .
Forcee were measured by hydraulic gages connected to the suspenoion
wir es. Two sets of wires ,.,ere attached to the rear
lift fitting to prevent the model from oscill ating during tests.
Air speed wns meaeured by a micro.manometer oonneoted to the statio
ope11ings in the jet diffuser. These readings wetr e corrected
to the air-peed at the model.
C}..L IBRA.TI ON
After tl1e model ha.d been properly ligne in the tunnel, it
s necessary to calibrate the hydraulic gages. This prooedure
wns carried out in th a rae manner oa desoribed in teet report 01.
C ro wos taken to covor the range of forcer; enoountered in the
tests e the oelibration curve deviated negligibl y from a
etraiyht line function in each case, the de.ta were expressed
ln term~ of a factor (kg/l mm). Calibrations were repeated for
ea.oh angle of pitch of the raodel .
TEST P OCEDURE
The model was first tested without protubere.nces and at i20 pitch.
Thon spoiler :/fl was attached to the model in different loca-tions
from the nose of the model and ot various angles of inclination
to the model ' s surface.
The model was aet at o0 pitch, and the s me test procedure wn~
repeated. Tare dr g of the wire~ was obtained by duplicating
the Tlire suspension system.
1 "Deecription of tho In~titute" by Dr Th Troller - The Daniel
Guggenheim Airship Institute Publioation #1 - 1933.
•
(
•
I
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I
;
f
....--
- -
-
' -
2 '1'
.. ,j .....
I -ir ~ -
mr:1 ~
-
'I~
0\
r
I • '
' l
c
I
"\
-; .. I - - -I ' ' 8
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-
- -
D. --
• r. - ..,., 1': .
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0 2.
(.. •
/( ,_ z~
~3 I
--~-------;t-
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RO 3
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I.
Photograph 1
..
'
/
'TITH RE.AR FINS :NO REAR FI NS
.JO DEL AT 6 o PITCH
PROTUBb.'RArCES Siroi:rr ON LEE11~ARD SIDE
I
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Page S
TEST RESULT.>
•
It we.a desir ed to express the effeotiveness of tho protuberances
as a ratio of the moments produced by them to the moments oomputed
by l~unk' a formula.
If? is this ratio --- Ma/ut
Ya --- measured moment due to protuberance
t --- thooretioal or Hunk's moncnt
where Mt : q x sin 2 oc.. ( ~ - k , ) x Volume
~ --- dynamic head
(1)
fX.. --- angle of pitch
\oll.:i..~e --- .023 m
(k ~ - k,) --- ooeffi cie~t of additional mass of ellipsoid = .873 aJ
S"C• +120 Pitch Spoiler
!Et - qo x .406 x
qo - 1.03 q
1 t - . 00842 q
..
1
.873 x . 023 = .00816 qo
q0 --- a·t ... odel q --- measured
r m .65 x cos 12° = . 634 m
f • .55 X OOB 120 = .538 m
d • .• 65 x sin 12° - . 135 m
Ma = FL x CF x f - RL x CF x r - ~ x CF x d
= FL x .00266 x .538 - RL x .0105 x .634 - D x .00833 x .136
Clf' --- Calibr ation actors (kg/mm) (See Tests f' l2-lc , 2o , 3o)
a ) "Fluid Dyne.mies for Airornft Designers u - pg 35 - Me.x }.funk.
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RO 3
. 17 FL - . 79 RL - .134 D
q
Page 4
Values of a r e f ound in teEt - 12 A, B and show v ery little change for
the differ ent looations of protuberancee.
(2) at o0 Pitoh - Spoiler #=2
Ma = FL x CF x .55 - RL x CF x .65
= FL x .00286 x .55 - RL x . 1111 x .65
= .)0157 li'L - .00723 3.L
CF --- Calibration Factors (kg/mm) (see Teat 11-0 - 2o)
•
•
,6S
l r
-+--
The moment Ma was correoted for existing asymmetr ies by eubtracting from
it the moment measured on the hull when the protuberancee were absent .
This is designated as lla (corrected).
I t was deoided th~t the corrected Ma at o0 pitch should be ~t lPast as
large as the measured moment for 30 pitch, or considered as 1/4 Ma at
120 pitch, to warrant further wind tunnel investigations of the protuber
ances. This comparison is shotn.i. in Teet 0-A, B. The moments a r e
seen to be much smaller at oo pitch.
On the test sheets it will be noticed that the l ift ~nd dr ag forces (FL,
RL, D) arc recorded as pres~ure heads, mn of alcohol, rather than in
terms of grams. This was done to simplify the computations, aa the magnitudes
of moments rather than foroes were desired.
No
poilere
a
b
J'~JT~:I. (' ·-; ENHSIM ~.IR 8'HIP :'.: NS'.:'T -:'•TTE
V r tioal Wind Tunr:el
R-33-10
12 A . .
Date of Test : _ Dec 29, 1933
'.T..' i• rr.e :
GOODYEAR ZEPPELIN PROTUBERANCE TEST (R-3S-10) +12° FITCH
-------
--· SPOILER #1 - MODEL 6R0123 -----
na r ometer -" --·' T ( r oom) =--- ; T (jet) =---· ; f =
--- -- ---·-
1 (3) (4)
----t-----·4-1
c 80
d
14S .
- -148-.
t
Rem~ r ks: + FL - readings increase
+ RL - " decrease
+ D - " increase
No
Spo
er
a
b
0
d
e
t
R-33-10
~ A HJ j,'T G T... EHH RT .I - "~Ip TN"'- 1 ,.,.TT .... • .no..\ ::;i.. u- ........ •.L · - .h' ~.n __ r "_ .... ... .!.
Ver tical ~in1 Tun~e: TP~t No : 12 B •
-----·-----
Dote c:: 'Iest :_ Dec _!9 , 19SS
Ti ITI" : --
Tf'~·. : GOODt gAR- ZEPPELII PROTUBERANCE TEST (R-33-10) +12° PITCH ---- --- ----- ---- ----·--·---
SPOILER i/f l MODEL 6R012S
-------- ----------
__ : T, r oom) --- ; .... ( .i et ) = ----- : f - - -
(1) (2) (3) (4) (6) (6) (7) (8) (9)
• l ; · -- --...- , -----,---...---~
D i . l 7FL 1 · 79RL l .134 D j ( 6 )-( 6) c:f> •
mm , i ! - (7) (a)/q
I I I
• 3so - ;;-t. 130 : • s 9. 6 I -22 .12 I• 1 7 . 42-+-:.._s_4_ __2 _0--+--.1- 9-9-+-----~---~
-~ -+--·=r= -!---
+ 635 _ s~_J-~ 2~_:_101 !~ _-4 ~ .~s ~ +3_2 ~ 96_ t_ii_a." I .7 95
• 347 - 21 I. 131 · ... 58.99 -21.331 ..-11 .ss 1 ... 62.11 . • 1a2
• 622 -_-6;-:: ~; :·l~~;i-:41~~;~6 ~1~:~ · .77~ T ____ I h
q
mm
H20
g [
80.3
148.7 --- ' l 80.2
-------
h I
148.2
--·--
FL
g
RL
mm mm
a - --
tt " I 78 ~ n j n - tt I " • " " I 600 ,. - " J -- .- :- -7~ -~ --: -1~.-- .! n r :- n -'1200 ~i---.. ---1 ----r ---·---t-- I +----, I
" I " · 80 ~ "
1
" - "l windwarti " " 105° " J
-b -
c
d
t------i---1 1 - - -f- I
e n I " I 233 nml " j " - "I " " " ~ 900 • l
-·--- ---·"T"" - - - -r- - - -- 4---~ _._I ----+----~--·-·--..._ ----1 I I l ' I I . . I
f " 1 " I 233 -. " " - n l eewardl " " i 90° " -- - - -1 - - ·- I -4-- -+ --+-·---·---..._ ------- -____ji-------'1
___g - - _ _:__--J- " I 37 u1J n I II - II j II n " 900 II I
h " I " I 3 7 mm " ! " - "j windwe. " " --- ~; - " -- ---+ ----T---· t- · · ,·--- -4-- - ---- ----
- - - .·- 1- .- - -I I I I i t 1 _J -- ,__r-·- - 1·
I 1 1 •
-----------
1-- ; -;·----..i.. ...- ·-- ·- -- -+--- - -·· _. . _ ~ ---
• I I - 4-- __ ! _ -i- ___ __.I_ ----+----- --{----
I I I
~----- -- - : - --- _!_ ____ L._ __ -· l __ _.. _ __._ _____ _;I~ _ _,,___ __ ..;...
p..,..,..., ,.. lr(:,
"~" •• :.A .. ? .. -..; ..
(1)
(2)
R-33-10
~ l\llN 'T•·'T r 'L"' ENH:<'JM ~· R~HIP Tl.Tsr-l 'TT'Tf'i'E .. ~ ... _11..1 -" r :.> - ·- "" _ J.'14 • .. _ .1. OA
Te~t :
VP rtical Wind Tunnel 'fest No :
-
----
Jan 3 , 1934
Date of Test:--·
Time'----·~--~~GOODYEAR-
ZEPPELIN PROTUBERANCE TEST (R-33-10) o0 PITCH
- - ------ -- - ------ --·-
SPOILER #2 MODEL 6R0123
--------- ------------ ----
'}Pre:ral Data: Parometer -=
739
•9. Ti - 19 - ' i r oom)---· 7 ,. T(.J. e)t -_ ---- .,
.119
1
q
mm
~o
3 ----- ·4 ·- · -5 · - --e- ---- - "?··-- - ··a··-· ---·--g-- --- --- ---- ---
•
- RL . FL
nun , mm
I - RL I, FL 1 Ma ! .00123)toois1) I
~ I
I
I
I Ma
~ Cor r
l
li/4 Ila !at 120
jpi tch
r
' .
D I
gms
I
47.3 - .6 5.0 -.00362'. 00785 .01147 0 l+ .078 571
...__1_9_.s---+_-_2_._0 __ 1_._5
1
-.ol45 ~0118_-~02~~ lo -=_ __t .134 934 .-....__--ii
, __ :~_.o--l·---3_._s--+- _4·~i·_o253 ~006~9 :p3159 J_~ __ 4~ ~43 1 1745 · __ __,:
(1)
.____4~. 2 +---1. s-i- 5 .o :-.0109 ;.0078 , .018~+ ·o:>~2 j_ _ _ - ~57~ --~ __ __ _ ---, .
1--7'!:._.1_~- 2 .0 __ !_~~_:-_:_0~=~~011~ -l~_o_2~. 1-.oo~s -I·---_ 912 f_______ '. ( 2)
I . I I I l 148.l - 3.5 -~- ~- j ~·?2~3 ~009~ 1.0348 +.0032 1 1735_~---+----~Y
I 47.1 o _J__s.o I _o __ joo~loo94
1
-.0021 l __ 571 1: ----f
(3) 80.1 - 2.0 10-:ol-.0145 ~0157 t.0502 +.0039 l 949 f:-- ( 3)
:1 · I ! - - - i ·
'_ 147 .9 --~~_:_-i. ==-~ ~-t~-0253 .01885 j.04415_t0125 '
1 1776 -II --------ti
r 47 .o o I s .o i o f 00942 .0094 I- .0021 i 571 , t
(4) ! so~2--:--2~011 ---9~.5 1-.0145-· i 01492 ~029~2 l.0069 949 ; 1 ( 4)
1· ··-- I• I• rI .' , , - - - --+-----,'
' 148.0 - 4:~ +-~~:+~~90-+01~7 - ::0447 __ :.01~1 i -- "17~~-i -~-....-~.--,J
ri--47_. 3 = 2 ._o,__ j --~-~5- f-01~~- t~~~ --1 ~0~-16 _t·_o·=~~~+~- ~ -·- -5_7_4 _ :_ · -------1·1
(5)1 8o.3 - z.o
1
. 10.0 1-.0211 lo1s1 l.0314 ... 0111 1 9so 1: I (5 )
I I , #
l ~ 48 ~ o " - _ 4 :_~-l ~. o J. ~289_f142 - I. 0431- : ~-o-il5 -j --- -- -;:~;5- 1! -~-~-------1~
; ~·9 -~-- l --~:o l o --~~~ j.o~~ t ___ -"--_s11_. .l.:. . __ _._ __ ~-
(s) so.3 - 2.0 10.5 -.0145 .01s5 .0310 +. 0047 966 (6)
147.8 - 3.0 9.0 -.0217 .0142 .0359 +. 0043 1785
l Rem·,;.r ks :
(8) - Test 12 A, Column 8 x .00842/4
(7)
(8)
(9)
(10)
(11)
R-33-10
'T pc.:..- +- Mo · ./ ..... . 0 B
Do.tP o:· J an 3 1934 Te~t : __ , ____ _
'l'imP :
GOODYEAP ZF.PPBI,IN PROTUBERANCE TEST (R-33-10) o0 PITCH
--- --- --------
SPOILER -2 MODEL 6R0123
----------- - ---- -------- ·------·-----
1
mm
water
2
-RL
mm
~ ar oneti=- r -= __ ; T( r oom) = _ _ ; "'(jet)
--- - - .. . - .. - .. - -. - - -----
3 4 5 6 7
FL I -RL ( FL i Ma l !!a- 1·--
Dm ( .00723j(. 0015~ I Corr !
~ I 1 i
=- --- .' (\. ' = --
9
D I
gms
----- ~--· I I : 0 6.5 i 0 I . 0102 I .0102 -.0013 i 579 I
---+-----t---~--. --+--- - 1 - --+----+---,.__--1
47 . 2
. _80.1--+--_1_._5 _.__1_0_.~_J~.0109 __ i_:_':.:_6~-- _· 0~74 .. ~ .0011_ ~ 966 1
I . I
a.o_ i o211 _ .012~-- _:03~:_J_+.0021 ·r -- ~·-_180~ __ __,
-~~_-_9 ___o_ __s ~-~~ ; . 0095 J_.0095 ! --~20 l- __ .__5_ 9~ -1 _· -- _
t--_ao.1 - i.o ~- _9.s __ J:.0012-! .01~9-i _.0~1 : -. 0042_ i----· 966 l__ __ -----i! l 148.0 - 3.0 7 .5 t.0217 ! .0118 j .0335 l +.0019 l 1805 t I 1-:--s·-r- ~ --~0-~-6 T-, ~n I. .~~~; :-.0008 r_- 56;-r- l -r
80.0 - 1.5 ! 6.6 -.0108 I .0102 ! .0210 I -.0053 1 I , , . -r-- - ' - - -r-- I ' l
148. 2 - 3.5 _l .:.~0 -l~~2~5 l ·0047 I .0300 ! -.0016 ;
I i i I I -·---:1----1----
47 .1 - .5 I 4.0 j-.00362 j .00628 I .0099
1
- .0016
- ;;~0- _ ~-:~ -1-6.~ L.~145-1 .01~ 1~02~1-r-.-0-01_6_ __. .._
1
1---- - -- -t I i .
24~1 - s .~ l ~:o_ - . 039s .i.001as !_ :_o~~:---+~1_60 " .
. I I I
- 47. 2 0 iI - 7. -. · o- ;-0- -- l .01099 .01099L - .0048 .i I 1 - -- ~ i,...._
80.0 - 1.0 : 12.0 ~.00723 , .01884 ' .026071 -.0002 . i -- I r--- . --~ - . -+--- --· -- - # ----i----~'
I _:~~o -_ 2 :o ~-:1:·~ , .01446 ! .01121 1 .03173 +.oooi_ t- . ~ 1813 1:--_______ ...
--- --~- ---· I L__ ____ l ___._ l__ _l _ ____ ...l.;:. ,___ __.i._ __- --=._.. J
148.0 - 3.0
46.9 - .5
----,__ I
•
946 f
'
1780 ·- ~'
562 • -f I
•
937 I I
~ --r-- - I
1749 l I I
• 1.- - - ·-- I ' 595
- - -----r -~-------f
974 I
R~rr.·..1. r k~:
(7)
(8)
(9
(10)
R-33-10
-~ ~A.•..1 1 .r...,.J,. ..,. G"T"l:' "ENH~... J IM ..~... . - RC='!l rp T- J'.'1I s...lo.. ,, ,...,. .,.f'TJ.' T&iJ'
Tf'!."' 4" .•
Vc r ti~ al Wind Tun~el Test No : 0 C
Date Ol' Ies-r. : _-1._an 3. 1934
TimP : --------
-- GOODYEAR ZEPPELI!i_PROTμBJJiANC~. TEST_ (R-33-10) oo PITCH=----·------=-
N.::.::OTATION Qj SPOILER =#2 - SJ>OILER SE?_AT._ 90° ~ AIRSfil_f_ SURFACE
_ _ ; T( r om) =--- ; T(jet) =---- ; f = ·-----
--· -----· - ·-· ··- - - -- - - ·--- ·---· .. _ -··- ·- -- -···---- --- -· -------
------~----.~----,------.----~----,.-----------...--~--.-1-----,------~, : i I i I j'
i !
~
( 1) No 81'1 i l ers. 1-_i..::;:..i_~,__--'-'"--+-:o;__---+----r--~--+-
1---<2) Spoil' r l oc_atj>d at 31 ~ f_!'.o~- b~w-'-- _ - · __ :
1
! ,.__ ~)-____" _ ._ . ." . i ."._ _4!! llll!L~l -..'.'. .. ..:'~-!l!g!).tfY . fair• d behin~ anoil• r • 1
._ _J .!.) __ _____'_ '- 1 " i " 42: mm ·t~--==-J-•t]'em4ined _ _ --"i _-~ _ .t l
( 5 \ r· I " . " 4~ IIDll n I " • ! l_ - - j ~'!..J..._ _.__ r--· -t- . - ---· - -·--- t ----,
1-~c.. .~. .., ,.,: .,.. ___" _ . ___ ·~ . __" .... .52! wn __" - -·~--- f- -+---+------
1 . ~
(7) --" ~-·-~'-_p~_mm_~--~ -+- -- ~ ---"*--~
( 8 ) " I 11 • " 6~ nm u n • I i !·
...__~.....__---1.___ ___ I__ 1 - --T=---+-----''--lf-----+---~----. ---+-----1
I I ' I ~ I
( 9) __ ---~-J_ ---~~t---"~52i mm 1 I stern. i !
f, 0 \ " I " I n 321 nm u I n ~ '. ' l -~~.--~ --- ·1 -- -- I - -;---+ - !----+----~---~. -- I
(ll .L . _fu19il,r /!2 at 164 mm 'fd Spoiler fl31t 57 mm from be,... __ - ·4------->!
----------t-- __jI_ _ _ .+; ·-- . !.- - -+-- ~ . --~ ____:_ ___ ,~--·-' I I I I . -·-j----· -r-·!---L.. -I- . + ·-· ·-t-~ -------;: -~_...__ _ ___..
-- -· - - - u --·-- t- --- '1
I:
·--~-----+~---'---- ; ~ ..___ ___ .:..__.. . ,._ l~ -- · ... - --I--.. .-... .- - - _...__'_ __ _,__L. ______ ;I.;; _ __ __. __ _ --J
R.,.,.,... r kc · .i :a....l.. ~ ~ •
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Additional testa were made dth the model at 6° pitch, and the
epoiler ~ 2 located on the leeward side, vmere the longitudinal pr easure
distribution (p8/q) TTaS a minimum. Teats were made with and
without rear fins. The effectiveness of the protuberance was stil l
negligible
(3) ~t +6° Pitoh - Spoiler h2
t c q x .208 x .873 x .023
= .00418 q
r a .65 x 00~ 6° c .646 m
f • .55 x cos so • .547 m
d • .66 x sin 50 - .068 m
Un • FL x er x f - RL x CF x r - D x CF ~ d
= li'L x .002475 x .547 - RJ., x .00376 a} x .646 - D x .00807 x .068
f =
a) Location of ~uspension ·re ohnnged .
. 32 FL - .58 RL - . 152 D
q
R-33-10
Ve ~~1· ~al ..,.in~ ~u~~e · .. " ..., ., - • 'J. .. .. J... - ---------
Date o.f· Test.:_ Jan 23, 1934
Ti rr.f" :
GOODYEAR ZEPPELIN PROTUBERANC!: TEST (R-33-10) -+60- P-ITC-H -
-------SPOILER :/f2 LOCATED 10. 9 PE. R CElr! OF MODEL'S LENGTH FROM BOW --- - - ---- ----
qarOf:1PtPr = --•' T 1/ r oom ) =- -- ; "• ( ,' ' t ) - - - •.
- - ---· - - · -· NO RE.A:R-FHiS · · ·-- - · · - ·· - - · - - - - ---
1 2 3 4 5 6 7 8 9
M I ---~---r-----r----,
f ' I d)
RL D ~ .32FL t58 RL j . 132 D I (5)-(6) T • I
mm mm • . I - (7) (a)/q
-t- . I
- 5-o-+--9s-.-s--+--3-s-.; I 64.o '_31.52l2o:s9l s.4s_u~-66 . 873 C o Spo lers
100 195.0 .890
q FL
mm
j
- --~~.?_ _ -t-2_s8_ _. ... -114. ? +-18!...:.o 92.1e -ss.12~_~4.68 -} 133.60 ·,_ ._891:; __- -+- __ _ .......J.
-----------~ -+- :__ : - ~ - ·-- I
~-48.5 98.5 t.=- 35_.si 1 _64~1 31._6~1 _:-2~~ 8.51_, .!:~0- .89!' j ___ r-
- _ 96 • 8 198. 5 - 7 4. ~ .. _ 12 ~ 423 ._62 --~~l 1 17. 09 j-!39. 64 ~26 ! Wi ..t. ;h;.~s~oi=l:..:::.e..::...;rs=--1
145 .2 292 .o _::_114 . i l,_93.0J Jl.3 .4~~6.12 i 25.48~134.08 - • 923
I 1 I 1 I 1 -: -- i ---- I WI~ REAR FINS
--·--r--- - -r---- I •
f- I ' I I so 121,6-~ + i~ ... 6 1 68 -9~~8.89+• 1 ,!l~ 0. 98
i 10_9____ 237 .0 + 20.0t-133.5 76 .84. I 11. 60 I 17. 62 46. 62
............l.. ...5....Q .._ 361_,Q. j~ J!2.l·9+_202.0~ll?.32 !. J-~1426.!JS 73.48
I I I I I ~
q
.466 N_o_ !'.:Q..O lers
I
I
I
f
I
I
!490.+-~~--+-~~~
I ' - ·- - ~ --·- i .. r-·~ r --- - -;- _L_ - - · ... - -
48.4 123.0 I l~!..5 II 694' ~-9 . 36 II 9 .57f - 9_.Jl_~ -~Q.~8 -· .4 27 '
j I I I I I --9-7--. 2 2-4·1.-0 ._!_4 7 I Jli th 8 oilers
145~ ~54.o . ~-~·oJ_~6.5 i1~_.~ .L--1!~1.2u 12 .3o_ _._ 4_9a _· _ __ _.__ ___ __,
GAI
RO 3 Page 5
CONCLUSIONS
The effectivenes s or the protuberanoee on the
pitching moment of the airship model , with the
ronge of Reyr old ' ~ numbers 11sed o.nd existine: \;:ind
tunnel turbulence, was not sufficient to warrant
further i nvestiE,~tion et other angles of pitch or
location~ of protuberances. ·.1th the protuberance
#? o:t; noP'5tion 2, oo pitch of the inodel , the
men sur ed drag \Vas less than with out protuberances ..