r 

<II 

" 

I' 

Nlt-SII 77+ 7~ ?~3 

NASA-TM-76963 19840012534 

A Reproduced Copy 

OF 

L~U~H\nV cor~ 

JUN 4 1986 

.1.ANGLE;Y RESEARCH CE~.TER 

LIBRARY, NASA 

HAMPTON, VIRGINI~ 

Reproduced for NASA 

by the 

-, 

'" ( ')'r~ 

\1 ) J" , "r , ........ ~, : "" , .. ~ ''C .. t 

'- ..... -

NASA Scientific and Technical Information Facility 

FFNo 672 Aug 65 

111111111111111111111111111111111111111111111 

NF00280 
4· 

f--el T 'l 

:".J": __ ~ i 'L 

{ 

i 

Her()ria~Jt i :2S 

. A\JA·rL~ ~:~Trj3-

i3p\.dc:e· " 

\" 

;- COt;:!!~~TRtH::T I CH=:J/ 

A~Jt\""~(1r 

lrif(}r~r~at i (~r-i :,)r-i lr~e 

t r arr~~( .. ri 1 c. UJ i r~ci r·r·.r-.• -' + I .... ·! !r- 4- 1 £"-.1-..... 1 s=- :-,..J';"';~ ~~ \. i :-;.!\_- \. i = __ 1\ ~ :: ~_J 

(Jf-!er at t Ofi", test 

fj t E~(:;Jss~(i i rl ~""~C!l1+C'_ --:~-... ..-..f 1 -........ v---s,; .. ,,-" :;:r. Ul- i\...i 

.-.~ ~r-.:--r-:. _~:-:. T ........ ~ .-: .~ t 

~~~~j~t.~t_.r-=-: 1 i ll·P:L 

i"_ir-·_" • .' i-~:~ .. l ¥ % 

FL(1~j 
~' 

/1 

, I 

1'- )t 

,; , ...... 

, 

-.-

.. 

I 

I '. 

r '~'!~""~·~;:--'t~~~<L''' ____ ':-7....-::'-'':'; :~~ •• ~ ..; •• .; .. ~~"'~ ....... +~ _:~~_ ... :..:...:..... __ .:..:..-!-:...:-..4." ~ ~ 

, .- ~ . !1 .. ~. 1 " 1- 1 f \ ' . ORIGINAL PAGE 13" 

OF POOR QUALITY 

.' 

NASA 'IECHNICAL MEMORANOOM 

'IWO-DIM::NSIONAL WIND TUNNEL 

(NASA-rn-7696J) TAO-D16~NSICNAL WIND TUhNhL 

(Ndt1onal A~rondutLcs dOJ SFdce Admi~15trat1on) 23 p li~ A021MF AOI LSCL 141 

.. .. -

NASA TM-76g53 

US4-20602 

Uncl<ls 

GJ/09 16834 

NA'l'IOIJAL AETW!lIIUTICS AND SP1\CE AD~~INI;:-)TR1\'rrOlJ 

HASHH1GTOll, D. C. 20,)116 AUGUST 1<)82 

, 

I' 

I , 

1 

! 

i 

1 

I 

~ 
,-

~ -

~, " ....- .. ~' 

. 

---------_.----, .... -----...- -..... ~ . • 

ORIGINAL ,PAGE is 

OF POOR QU ~LITV 

I'~ABO ftTe.a "~Cl 

I. A_'"~ NA A TM -76963 12. ~A ........ "ho J. Qu',.CIQf·. C$f~ UO. 

.. 'nl. P4 ~"4 . . , S. II,.... °A~gust 1982 

Two-Dimensional Wind Tunnel , •• " .. 1 .... '".0 ..... ' •• " ... c ••• " 

f, 

7, A.·".o(l' •• " .. r .... ", 0, ....... ', .. n.p ... H .. 

It. v ... U"" " .. 

" 

t. p.,r ..... ". O, • ..-I.ett .. U_. c:a4 A~.to. •• 

It, C .......... c.;' 1:0-

MASt... 142 

SCITnAN . U. ',,. •• n.,... .... Poel.4 eo •• r04 Doll: 5456 

c: "'" ~... n .... J....... (0'" ~'nnn TE'enelaticn 

12. sU:'"'''' Al'iJa n_. eft" hu.. •• 4tl0UQ rOQQutiCB ~ S~Qeo Ada1a1at~Ot!aD 

VeahlDtltoa. D.C. ~O545 14. ~~~. Co4o 

I--

II. ",,"'---ur~," 

Translation of "Nijigen Fudo-Tokusho" National Acro,pcco laboratory 

News, Tokyo, Jopon, Special Supplement, No. 246, November 1979, pp 1-8 . . - t- o 

10. A .. ,...· 

Informotion on tho Japanese Notional Aerospaco laboratory 

two-dimensional transoni-: whd tunn!:l, 

completed at the end of 1979 is prasent~. 

Its construction is discussed in deta~l, 

and the wind tunnel structure, operation, 

,,1;.~s,t .resul t$, ~nd,~~ture,plaDs are .... . . . . " ' ,- presented • , --

-

17. £to, t.'p~ (w~t:3 t7 A=~~) tJ. Ct.,"hncaf~ 

Unc) ass Hied - Ulllimited 

19. 14-...., CI.lelf. (~t3;t. ~..., 0. ~tr ClouS'. (~ ~. ~.J i" ... ~dP~ C!. P.;i:> 

, Unc:1QQoUf.CfJ C'l4clODQ1lZ1~ 8 

, 

i 

I 

_I 

I 

, 

I 

"I 

. 

" 

i 

t 

, 

I 

I 

· 1 

! 

I } 

I 

i 

I 

I 

I

II 

: I I , 

, , I 

;JS4-:J-6iP();7# ~ " I' 

IV" /5~ ~97 S
'.'f 

,Ir 

, 

II 

, " 

r1 ' 

""'~ '", 

" 

Two-Dimensional Wind Tunnel 

ORfGINAl PJ\Ot: rn 

OF POOR 0U/~LITY 

Seven year production of atwo~imensional wind tunnel facility 

with a total budg3ted cost of 1,564,000,000 yen was cOMpleted at /1* 

the end of 1979. Operation tests were safely completed in July 

of this year and full-scale tests on wing section systems will 

f1nal1y beqin in 1980. We will take this opportunity to 

comment on the backg~ound ot thlS wind tunnel facility and its 

construction and to introduce the wind tunnel structure, operatl0n 

test results, and future plans. 

1. Background of the Two-Dlmensl0na1 Wlnd Tunnel Facility 

It goes without saYlng that a huge jumbo jet exceedlng 300 

tons is supported in air by its main wings. However, 

how such a de11cate and fragile component can produce so much 

strength, and, once thlS lS explalned, how even better wings can 

be produced are lmportant aerodynamlc problems. Nevertheless, 

modern transport planes travel very quickly and the SST, which flles 

at a speed twice that of sound, has been developed. There can 

be no comparison of wings for flying near the speed of sound 

ot' 'at' sp~eds hi'gher' tn-an' t!his 'and "those ~Hngs that are used 

at relatively low speeds, Wh1Ch were mainly developed during 

Wor 1d War II. 

The most characterist1c phenomenon that occurs wlth hlgh 

speed wlngs lS the productl0n of shock waves. When a region 

of flow that ~xceeds son1C speed eX1sts ln the flow above the 

wlng surface, pressure waves that appear from varl0US locations 

on the wing surface gradually accumulate untll the strongest nnd 

sharpest wave 1S formed. When this wave is formed, an increase 

1n wlng drag correspondlng to the operatlonal energy spent 

in producing this wave occurs. In add1tlon, the flow 

easily reflects off the wing surface at the posltlon corresponding 

to the source of th1S shock wave and at ltS downf10w. When 

th1S flow reflect10n occurs. there is a reduction ln the liftlng 

*Numbers ln margln lndlcate foreign paglnation. 

1 

--"- \..v ... 
,.. 

. . .. 

power (power which lifts the plane) produced by the wings and 

an increase in drag. When this condition builds up, so-called 

shock wave scalI occurs and normal flight conditions of the airplane 

cannot be ma1ntained. 

Heretofore, studies aimed at eliminating the effects of shoc~ 

waves, which destroy the properties of wings during high speed 

flight, have been carried out. A breakthrough was made by 

Piashii of the United K1ngdom in the mid 1960's. He proved that 

there is actually a cross section of the wing where shock waves 

are not produced. even 1n high speed flow near sonic speed. 

which had been theoretically pursued by some researchers. 

He also explained the properties of the flow at th1S time. 

Many researchers continued with his studies and developed theories 

for shock wavefree w1ngs. Our research lab also presented good 

experimental and theoretical results. Today the f1rst stage in 

these studies has been completed and research is now be1ng carried 

out not only on 01 shock wavefree transon1C wings, but also on 

transonlC wlngs that present a small increase in drag and have 

a h1gh llftlng power, even when shock waves are produced. 

These types of wings are all characterlzed by the fact that 

the surround1ng flow 1S 1n a supercriticoJ state (condltion where 

a reglon havlng a speed exceedlng sonic speed appears) and 

therefore, they are called "supercriticoJ wings" to dlst1n9~ish 

them from conventional wlngs. In short, the cross sectlon of .- ... ' .. ' " .. '. '. .' . these super-cr1t1cal wlngs is designed so that the damag1ng 

effects of the flow are not exerted on the back half of the wir.gs 

because shock waves produced below the supersonlC speed region 

are sufficiently weakeneewhile llfting power is produced by employing 

a strong low pressure produced inside the supersonic speed region 

above the wlngs. As a result, the aerodynamic efficiency MxL/D 

of the wings rapldly 1ncreases 1n comparison to ~onventional 

wings because a high 11ft/drag ratio L/D of the wings can be 

malntained even though the maXlmum fllght speed of the plar.e 15 even 

2 

~ 

I 

\ 

I 

! 

I 

I 

I 

I 

I 

• 

I. 

~ 
r -, • 

higher. Since this aerodynamic efficiency is directly proportional 

to the transport efficiency (~ cargo weight ~ distance/amount 

of fuel consumed), an increase in this value is an energy saving 

measure and plays a large role in eccnnmically improving 

aircraft transport. Consequently, res~arch on this type of wing 

is being earnestly pursued by many countries throughout the world. 

In Japan "Research on Transonic \'lings" was mentioned as one 

of the important researc:h tOP1CS in "On Topics for Advancement 

of Future Aircraft Technology and Plans to Achieve this 

Advancement" in reply t.) Inquiry No. 8 carried out at the 

Aircraft Technology Convention in December, 1971. Furthermore, 

"The 'lWo..Dimensional Wind Tunnel" was given as a plan for a new 

facility that would be necessary in order to make this progress. 

The same comm~ttee no~dthe necessity of research on = 

transonic wings in "Wing Sections Suitable for STOL Aircraft" 

during the "Basic Progress in STOL Transport Systems in Japan" 

session in December of 1975 Based on th~s information, twodimensional wind tunnels are being planned as special wind tunnels 

for test~ng transon~c w~ngs. 

2. Construct~on 

Construction of the two-dimensional w~nd tunnel was 

':) .. , .,~ 

planned for a 3-month period from 1973 under the instruct~ons of l~ratory "Head. "Y~mauc·id. 'an'd '2~d Division 'Head' Ch"uken The total:" ..... 

budget cost was 850,000,000 yen, g1ve or take ten thousand 

yen, including the cost of the add1tional air compressor /3 

and air tank. The first period operat1ons were appropriated 

in the budget for 1973. However, th1s construction plan was 

established for cases when1from the start of construct1on, 

important tests had to be carr1ed out. 

At th~s t1me the 1ndustrialized countr1es uf the world were 

h1t w1th the so-called energy criS1s and the increase in tpe 

cost of petroleum 1mports from the M1ddle East. The effects 

of th1P cr1Z1S were gradually felt from about May of 1973. 

By the end of 0 ctober of the same year in which f1rst bids for the 

w1nd tunnel were carried out, prices were in a frenzied state 

and these r1s1ng pr1ces were d1splayed by the unsettled mood of 

3 

--I 
~ 

. .. I·· .. 

/ 

.... -- ",,-," ..... ~, ~ ""\" , .... -.,....-.----------

the market. Therefore, it was difficult to foreca~ the production 

of the wind tunnel at this time. Consequently, revisions such 

as omission of the first diffuser because rapid diffusion is carried 

out with the downflow of the pressure regulating valve, 

reduction of the plenum diameter from 3.3 m to 2.5 m, 

elimination of the settJ ing chamber silencer and the second diffuser, 

etc. were carried out up to the third bid, when negotiations 

were broken off. 

As a result of these complications it was determined that 

in the long run the wind tunnel could not be constructed w1th the 

initial budget. Thereupon. it was decided that the uncontracted 

operations would be deferred and that a new plan and budget would be 

made for 1973. Moreover, an additional budget would need to be 

made for the def)c1ts after 1975. However, although there were 

difficulties in paying for the necessary budgeted items because of 

the trend 1n prices, the realizat10n of th1s plan was finally 

forecast in the 1975 budget and therefore, the 1st and 2nd period 

operat10ns were started w1th budgets for both 1973 and 1974. 

The total budgeted cost that was forecast for the construct10n 

of the w1nd tunnel, includ1ng the air compressor, was 

1,450,000,000 yen 1n contrast to the or1g1nal 850,000,000 yen. 

Completion of the project was postpo~ed unt1l the end of 1977. 

Afterwards there were var10US problems with contracts 

.... ~n.~. o~~~at:~n~. c;.? C;~l)s.tp~ct~~!l. w<:p .. d.e).?y~~. annually for var10US '. 

reasons, and therefore, rev1sions had to be made 1n the budget. 

Moreover, during th1s t1me the superv1sor in charge of the laboratory 

was replaced three times and the laboratory head and the division head 

were also replaced tW1ce. Nevertheless, regardl(Bs of these 

difficulties, the surpervisor and operators completed the 

w1nd tunnel itself by the end of 1977 [1] and the s1lenrer by 

1978. Production of the air compressor was f1nished in 1979. 

The But1re faci11ty was completed 1n 7 years. 

4 

i 

I 

I 

'" p 

:.
, , , " 

3. structure of the Wind Tunnel 

The entire wind tunnel is shown in Figure 1. This wind tunnel 

is an intermittent blowoff wind tunnel. The main parameters of 

the design are 

T es t area cross section •••••••• width: 0.3 m, height: 1. 0 m, 

Mach number range • • • • • • • • • • • • • •• O. 2 ~ 1 • 2 

6 Reynolds number •••••••.•••.••••• 40 x 10 (M=O. 8, c=O. 25 m), 

'lAnd flow duration ••••••••••••••• 9 ~ 100 se co nds. 

The main feature of the wind tunnel js that it has a test area used 

for two-dirnens~onal models and tests can be carried out with a 

high Reynolds number. In order to realize the aforemenlioned and to 

carry out several new tests necessary in modern wind tunnels, the 

following po~nts were taken into consideration. 

(a) A plug-type pressure regulating valve was employed and 

special care was taken so that there would be little pressure 

loss from this section [2J. 

(b) In add~tion to placing a porous plate and screen ~ns~de the 

settling chamber ~n order to improve a~r flow properties, 

a flat sound absorb~ng plate was also installed. 

(c) The lower wall of the test area is a multigrooved wall 

and the outlet rat~o can be cont~nuously changed. Moreover, 

the ent~retest area ~s wrapped in the cyl~ndrical plenum 

in order to make pressure resistance effic~ent. 

" , "(d) , , It' ~s 'possi'bie 'to' control boundary layer absorption " . 

of the s~de walls w~th the model attached ~nside the test area. 

(e) Plug-type 2nd throat valves and pressure regulating valves 

were used for the prechargro operat~on system, which will be ment~oned 

later. Moreover, the flow system at this section could be completely 

closed. 

(f) Wlth regard to pollut~on problems, special attention was 

g~ven to the silencer. 

5 

\' 

I 

.... 

~ 
" 

~"':-"":-4-'!...~ .. __ :. ... ""': __ - =--~ .... .! __ .:. ... "":._::::=.:..._:~-=-=-..,~ _____ -:. .:. ........ ~_ • ___ ..... _~~ .... .............. _..0: _.;'~ ... _~ ___ ~--... .. 

. . .~~-"T" .. --

air regul. .{set:'"'plenum ;; 2nd ~I ~ 

vrilve charr.bert.l.t1 t:hrt val ~I I icdzi .. ~ va" 'i 

ccmpr. fl.aA' dlanber test "a~"!ifiQl tL .. ---- :...""" .. - -T ' 

~ ~ I~m area 33.725 cont:r': valve -

Figure 1 • N A l Two - d t m 0 n s ton a I T ran son t c 

Wind Tunnel 

3.1 Wind Tunnel Frame 

Each component of the wind tunnel is mentioned in (3} 

of the bibliography. The main items will be mentioned here. 

With the exception of the pressure regulating valve housing, 

which is made of cast steel, the wind tunnel frame is made 

of welded steel plates. The silencer housing is made of reinforced concrete. 

f, 

Pressure regulating valve: inlet tube diameter of 0.8 m; 

the downflow section has 9 individual diffusers 

lined up above it. 

Settling chamber: diameter of 2.5 m and length of 6.5 m; 

one porous plate, 12 sound absorbing plates with 

.' a length 'of '1 m' and, \'1idth of 10 cm, and four screen~ 

(one 10- mesh screen and three 22.5-mesh screens) are 

installed inside. 

ORIGINAL PAGE (9 

OF POOR QUALITY 

I 

I 

I 

I, 

I , 

I 

I 

.1 

I 

; 

, 

, 

I 

I 

... 

~ 
· , 

, . -... .... 

~ 

ORIGINAl. PAGE IS 

OF POOR QUALlTY 

rCompressed flow chamber [41: sonic nozzle, length of 2.5 m, 

compressed flow ratio of 16.35:1. 

Test Area: width of 0.3 m, height of 1 m and length of 3 m 

(section where the groove width of the multigrooved wall 

is constant), top and bottom multigrooved waUopening ratio 

of 0-10%, the downflow opening angle can be varied by 

± 0.7 • 

A glass window or sintered metal plate (boundary layer 

absorption plate) w~th an effective ~iameter of 0.465 m 

and a thickness of 0.01 m can be attached to the side 

walls to which the model is attached when necessary 

for the experiments. 

Range at which the angle of incidence of the model can 

be varied -- .150~. 250 • 

Grooves used for the flow measurement probe are located 

behind the downflow 0.7 m from the center of the 

model attdchment. The probe can travel up and down 

these grooves 800 mm. 

Telev~sion caro~ras are installed above and below 

the model attachments to observe the model and the 

air flow. 

Plenum: diameter of 2.8 m, glass observing window w~th a 

diameter of 0.25 m and e lh1ckness of 95 rom 

, , 

After suct~on control valves are placed at .1 

r'i'gh't a'n'gleS: 'to' the "a'l.r"flow 'from the right and left of 

the plenum, they are j01ned together as one valve and 

the plenum is then connected to the ins1de of the silencer 

with this suctl.on control valve (250 rom t:1 rotary valve). 

" 

1 

r 

, 

i I 

I, 

~-- - ~----. --.- ~ 
.: 

" 

.\ 

./' '\ 

ORIGINAL PAGE iSi 

OF POOR QUALITY 

2nd throat valve: inlet tube diameter of 0.8 m Diffuser (5): 

contains 2 porous plates (the opening ratio is 27% at the upward 

flow side and 49.7% at the downflow side); the downflow 

bottom has the same porous cylindrical surface as the downflow side porous plate. 

Silencer (Figure 2): has a width of 10,m, height of 19 m, and 

a length of 40 m on the outside; part of the silencer was 

constructed in two stages with double \ialls. The silencer 

is a flat plate-type silencer. There are seven large sound 

absorbing plates, 13 medium-sized sound absorbing plates, 

and 21 small sound absorbing plates inside the silencer. 

The size of each sound absorbing plate is, respectively, 

0.9 m x 7.35 m x 5 m, 0.7 m x 7.9 m x 2.5 m, and 0.4mx 7.9 m 

x 2.5 m (width x height x length). 

' .. 

The actual reduced sound property is 82 db (0. A.). 

r , 

i 

§ . 

... 

-, i Sound Ie absor. :' II;' mat'li , 

~ 

5m 

~~ GL 

. 1 t 40000 '., $ oU~d abso~~ng p a r=e_~~c:=:-r-:--~-"-8 

r 8gg c=> I c:::::=.... .:._ ..:_-:: :- }' • I ~ ~ <=> g I c:::==:- .::-::--=)!"'" ' , __ _ ~ q --- - ---=~- Ie::=:' c --

__ • • I I 

21 I c:::: ::::..:------1 I ~ \,.... ~ fI 

I - ~ - ~ - .1 I'. I 1 J --.1 .' ,J. 

8 

Wind tunnel'Diffuser downflow ~~ooo 

-- ---

Figure 2. Silencer used in the Two-Dimensional 

Wind Tunnel r 

.' ' 

section 

'- r. 

j 

--- --~--- --
'. 

.. 

~-q.tr~.~ ..• :: •. :: .. ::'::_"~ • ..:.::.: ..... : :-::::;...:.r:--.:_-r. -"'f ,~ .... " -" T ~ '-':' ;;;.. ";.;;..-~~.. I ~ ....::l..L._::.:.:~:. .. \> ... -....::="-=:..:..:: .. : F!::..:t.:z:::.::oc ... 1' .. :: .. ::....... 

3.2 High Pressure Air Source 

ORIGINAL PAQr m 

OF POOR QUALI1Y 

The high pressure dry air (maximum pressure of 21 kg/cm2 abs., / 5 

dew point temperature of _SqO C ) comes from the air compressor and 

high pressure air tank shown be!arI, wh:lch can be used with other 

wind tunnels: 

return-flow air compressor: 900 kW x 1, discharges 6,000 Nm3/hi 

Lysholm air compressor: 1200 kW x 1, discharges 6,000 Nm3/h; 

centrifugal air compressor*: 3450 kW x 1, discharges 18,000 Nm3/h; 

1st and 2nd air tanks: diameter of 10 nm and capacity of 523.3 m

3 

each; 

3rd air tank*: diameter of 12 m and capacity of 904.3 3 

m • 

3.3 Measur1ng Devices and Data Processing Equipment 

In the wing section tests with th1S wind tunnel the lifting 

power evaluations were carried out by measuring the pressure distribution 

over the w1ng model. Drag evaluations were carried out w1th 

backflow (wake) mc;;suremerm. A balance system to measure the three 

force components was not set up. Four scanning valves were used to 

measure the pressure d1str1bution over~ the model. After this 

analog data was amplif1ed, 1t was recorded on a data 

process1ng d1sk through an analog digital converter. After 

tbe exper1ments" ,th~' 1mportant ·Oata were .. transfer:red to .magnetl.c 

tape and sent to the computer center where computations were 

carrieo out, or the tape was transmitted to the CPU of the 

computer center, where the necessary computations were 

carried out. Moreover, after the experiments, s1mple computations 

*These devices were set up according to the wind tunnel fac11ity 

preparat10n plans., The air compressor should be completed by 

the end of'l979. c, " 

.-

9 

c \..::-" " ~ 
'. 

-... . . 

... 

--

~ ~ j ~ • 

ORIGINAL PAGE ,~ 

OF POOR QUAlIlY 

can be carried out with a min~omputer used in recording the 

wind tunnel data, which would also serve as d monitor 

(YHP MX-1000s~;~ 2171). Then these results would be 

output from the lino reader, the grtphic display device, etc. 

(should be completed in 1979). Figure 3 is a block diagram of the 

data processing equipment. 

a 

b 

c 

d 

e 

f 

.... 

II " • It .. 

J f".:1~"'1I:1I 

16111216<,t) 

1". :1 ''''1II1I{ 

ItHalln.t) 

k 

.rz;r;-n I -e~J 

F1gure 3 Block D1agram of 

the Measuring Devices and 

Da~ Processing Equ1pment 

'1 

Key: a. 

c. 

forward amplif1er, 24 channel; 

wind tunnel data (24 channel» .. . . . ~ • • I' •••• 

b. 

d. 

high level s1gnal (8 channel); 

dig1tal analog , converter, 

2-channel; 

, l 

e. 

f. 

h. 

j. 

operation control room location; 

central processing unit; g. 

maX1mum 45 kHz; i. 

digital output k. 

(each type ]11 bits); 

one onol09 " dig1 tal converter; 

dig1tal output 

(each type 276 b1ts); 

YHP -1 000 series 2171; , 

1. pr1nter-plotter; m. XY plotter 

10 
.. 

, 

.' . 

3.4 Operation Control Devices 

There are devices to control each of the valves and 

movable parts of the wind tunnel coroponents in accordance with 

the necessary program. Each component is hydraulically drivan 

2 (pressure of 140 kg/cm). Each part can be automatic.lly driven 

during a1r flow 1n accor~ance with the program that is be1ng used 

by sett1ng the t1mes for valve open1ng and closing, etc. 

pr10r to air flow. The operation control features of this wind 

tunnel are as follow. 

(a) It is poss1ble to control the Mach number. That is, 

the Mach number 1S measured during a1 r flow and automatically 

controlled so that 1t 1S a set value by feed1ng the Mach number 

d1rectly 1nto the control dev1ce. Therefore, th1S d1ffers 

from convent10nal w1nd tunnels only 1n th~t the Mach number 

can be set. 

(b) After the pressure is detected and converted to d1gital /6 

slgnals to carry out the necessary computations 1n the control 

systems for the pressurt regulat1ng valve, the 2nd throat valve, 

and the suct10n control valve, the computat10ns are converted 

to analog Signals and transm1tted to the actuator. ThUS, 

a sem1d1gital control system 1S employed to 1mprove the control 

prec1s10n for the settl1ng chamber pressure, Mach number, etc. 

The angle of 1nc1dence of the model 1S controlled w1th an analog 

s'ysteIt; ana plans;' de'tect'l.Oll,· etc. are controlled W1 th a d1g1 tal, .. 

system. The a~gle of 1ncidence can be cont1nuously changed 

W1 th 1n a set angle range or changed in step:> whereby a pitch-pause mode 

is repeated with.to different angles of incidence being obtained. 

(c) In addlt10n to conventlonal operat10n systems for blowoff 

type w1nd tunnels, precharged operatlons systems may also be 

employed. Th1S 1S the method whereby after a1r near the preset 

settllng chamber pressure 15 stored between the pressure re~ulatlng 

valve and the 2nd throat valve pr10r to alr flow, the state of 

a1r flow 1S entered by openlng the 2nd throat valve and the 

pressure regulating valve. This precharged operation system 

is used to carry out hlgh Reynolds number tests (tests with a ~lq~ 

settllng chamber pressure). The advantages of thlS system are 

11 

, 0 

• 
, 

\ 

'. 

" 

'{ \ / 

\ 

'. '" ~~JCIE4;a);q:;zW;;:;C;O,JPf4a4i¥u.;;:ut1li1l¥f\ifJ!'M"P::;::$'i\iiA ¥jiWjilJ>~~;;:;:;;::;;;;;;,W"'~fSi~g;:;; ..... ~~~~ 

f 

....... I -"'- II! - - - • • - ,''''-'''''''' 

, , 

mentioned below. 

ORlQ{Nttf.: Pllcr F? 

OF POOR QUt,LIIY 

(i) In addition to the air stored in the lst-3rd air tanks, 

the settling chamber of this wind tunnel also stores air and 

therefore, there ~s an increase in the amount of air stored in 

the tunnel and consequently, air flow lasts longer. 

(ii) With conventional operations systems 

it is necess~ry to compress the air in the wind tunnel by 

penetrating the h1gh pressure air from the pressure regulating 

valve and therefore, the temperature increases. Th1S type of 

drastic change is avoided with prechaIged operation system. 

By avoid1ng these drastic changes, poor a1r flow conditions and 

destruct10n of the model can be ~voided. 

(i~i) Bec~use the air tunnel is operated at a condition 

near a set settling chamber pressure, it is possible to reach normal 

conditions in a short amount of time. 

The aforement~oned w~nd tunnel components are shown in 

F1gures 4-8. Moreover, one example of a schl1eren photograph 

is g~ven 1n Figure 9. 

~ ~,~ •... ~ ·1 ~-L!!..:_:' 1 ,....,i.b.~ c:l 

I ( I' I, ,

" .... '. .. ....... . , , . .' " . \ • .. ,' .. ~ .......... .. ....,., ..... J, .. 

, ' 

12 

• ...J '.----. ...... .--__ 'lr,.'*, 

-

Figure 4~ Two-Dimens1onal 

\~lnd Tun;'lel, Outside appearance; 

front view: sllencer; 

bottom right: ,.,rind tunnel building. 
.. 

.. 

, , , , " 

ORIGINAL PAGE IS 

OF POOR QUALITY 

. , " i ~IU f ']\." 

t... ~ II ( J~.-1,;! J __ Jr, 

-

Figure 5. Two-Dimensional W~nd Tunnel 

Pressure regulating v~lva. 

Bottom right: bypass valve for prechargcd air operation. 

,",.- ~--""DtC~J ,) --"-'ot\ '. ~ _. "CI r;. ~ 

• I l7: )\Yll ,,:-"=' I ". 1 J• • :. /;,. ., , . " , , ~ 

, "( ~" \., .. '-" ,--,-;' J 

'-~'::;:';-- ~ ":' :~ ' .. -:-;-~J~~, ~ ,~ :- -... . ...,) ..... -. .. . ,.t, :..::.::, .'~, "'t __ ",_. _.' ,. ___ -:"~J ~ ~ 

II. ~.o~_~~ - --

F~gure 6. Test section 

(Nbdel hav~ng an angle of ~nc~dence). 

, 0 

13 

" . 

1 

1 

I 

I 

I 

, 
" 

t'!!'f'lf;t44 2 ....... ,; Ai :. ; .. < W"" , 5 '. P' ,s .W .... f CO $ OJ: ;,1 j':.~_"_ j •• ,-4 (4:az:44:;:U!4lU$' h,a=,¥J' __ CII(<<f'""*""'!Il,can,'(4 . " " , ... .,,~ • -.--' -- -~-' ... -. - .~. ---. ..... ,«11 

. . -.. " . 

14 

ORIGINAL PAGE t9 

OF POOR QUALITY 

.. .-.--............, .. ""'~ 

r ,. r~ ., 

" ... ..... '" .... , •••• ': I. 

~ 

i 

Figu~e 7. Operation Control 

Board • 

{: ; ",-~: ','. -'-, ......----r'.r~ ." 

g J j ~ .; , 

'''j~!1r:. . : 11 • '11 r I _ 

., ~ f "I, ~l ' # , ~ • ' , . . .. "r/. • J. f g ;1 U il,:: Hi 

;'~.l. i' '~1 :J 

~11~:1~ I J ,I:!~, s" , I • 

- -.!'o~"~ J ... ;-; ______ ' •• __ ~ t,;" 

F1gure 8. Inside of S1lencer 

(Acoustic pone Is) • 

, " 
" 

, , 

. . . -... 

............ ,...,,~. .. 7... "W," 'W"." = . . w ...... _ I~ .... 

-. 

ORIGINAL PAGE'S 

OF POOR QUALITY 

" ~. ./'" 

--..:..o:a... 

~ , Ac' ~ . .{ ...... ~ ................ 

Figu~e 9. Sch11eren Photograph 

(wing section NACA 64A410, M=O.849,OC:2°, R

e

=1.4 x 107 ). 

4. Operat1on Test Results 

Some of the data process1ng equipment and a1r compressors 

have not been completed yet. Eowever, as most of the w1nd tunnel 

fac111ty was complete, 1t was determ1ned that 

could be carr1ed out and therefore, 141 tests 

a period of four weeks since June 25 of this year • ... . .. . . .' .. ' 

4.1 Overall Performance 

air flow tests 

were performen over 

The exper1mental capab11ity range of this w1nd tunnel 1S 

shown in Figure 10. A1r could be passed safely at the 0 marks 

!2 

in the F1gure. Normal cond1t1ons were obta1ned after a certa1n amount 

of t1me and 1t was shown that var10US types of wind tunnel tests are 

possible. The maX1mum Mach number 1S somewhat lower than planned 

volu~, at 1.15. The durat10n of normal conditions, wh1ch was 

computed from the expcr1mental results,1s also shown 1n the 

F1gure, which w11l be explained later. Normal cond1t10ns 

were mainta1ned for the shortest amount of time when tests were 

curr1en out Wl. th a high r-\ach number anCl maximum Reynolds number. 

However, even under these cond1t10ns, normal f11ght could be 

maintained for 5 seconds. Th1S was the exact amount of t1me 

l~ 

\ 

I 

I 

I 

I 

I 

,,-. 
,.>-

I, 

/ 

- . 

~ 

.. 

iJl,,"r~iI~' ° ,n.,' ~- • ..-~"""""="' III .. , G jI' : I • Ii ... • 'r ~_ .. "\ -.. • 

..,...... • ;p_.,. ~ 

0 On .- 'r< ... "/ ."" .... , r .... , .. = ~ 

,-_-.:-!" .. , \, ----

. .. _-- ----- -----_..-, "', 

.' . 

necessary to test ons angle of incidence. 

ORIG!NI-\!.. p:'\a~ is 

OF POOR QUALITY 

R >c ur' std. length O.2~ m, 

50 

40. C. 

expertl. 30 

cond.' 

201 range 

10 

condltloru I 

!lIIo ............. 

.-.. - :,.0,- .J/ ... ..... : .............. . 

normal condJ tlora -- 20 seconds 

• • 

operation test 

0 0 02 0.. 06 08 1 0 1 2 1 4 Hach number M .... Figure 10. Experimental Capability Range: 

Reynolds number venus Mach number. 

Changes in the operating', conditions, pressure, pressure 

ratio (function of the Mach number), etc. of the essential devices in the wind tunnel during air flow are shown in Figure 11. 

These recordings were taken ... ,ith a settling chamber pressure 

of 12 kg/cm2 abs., a set Mach number of 0.8, and an air flow time 

of 8 seconds. Five seconds after air flow, the Mach number «po -p) /po) 

became constant and normal condit~ons were maintained for about 

3. s.ecqnd,s, t .' . 

o ,~ 

16 

, 

, . 

. ,

I . , 

! 

I I , 

I 

I 

~ 
,J 

" 

.. 

<, 

"N 

~ 

\ ,. " ,""It '..,--: _-- 1 • .:.... :::::". !",!,,:!,W,.. ,:-!'':::-=_ -" "( .... I'..... = _!t.. ...~-==-,,,,,,,,,,,,,=--z..~ 

Key: 

• 128 ,. ~ --..... .. --... -

~-.--,.-.- 12ka/cm' • -C$"l1:. (,/,1) 1".-:J 

:J..-------,-i - -UlllClIi ~ '~lu·ftn ) 

'fH2ll3lf 11 

(e) 

~r.!ffJ:;l1lI 

- .. --- . 

II:;~ ) .." r-----........' "-

""-

,-_~" vu·..... ,.--.- j 

........ " ............ .-. 

CtlfGfNAL PAGE is 

OF POOR QUALITY 

a. settling chamber pressure p ; , 0 

b. 

d. 

settling chamber temperature; 

c. plenum pressure,~ temporary shut-off 

e. 

g. 

h. 

air tank pressure; 

pressure regulat~ng valve 

2nd throat valve opening; 

. j.. 1 minute,;... . ..... . 

wind tunnel shut-off; 

(state near precharged 

cond1tion mainta1ned) ; 

f. pressure ratio (p -p)/PO indicator 

opening; of Mach nu£ cr; 

1.. precharged; 

.... k ... :wind tl!nnel oI?e.r:atiqn.;. . 

In. I second; 

n. suct10n control valve. 

Figure 1,. Oscillograph trace of the prechorged air operation and wind tunnel blow. 

1'1 

I 

\ , 

\ 

j 

1 

1 

, i 

I 

. , 

" 

":" 
/' 

, 

,~ 

\ "__ ~~ ... ~ ... ~~!.!"' ... --r--""!,,---:,.~":::,~,,,:::::,,~"-~:=a eo IS ~ .,......=:-;.;.,. 

.. 

"'J 

// 

, .... . .. 

~-

.... -----. 

: I 

4.2 Duration 

Just as air is blown I off from a tank with a finite capacity 

in a blowoff type wind tunnel, the during which which air can flow 

is also finite. Air can usually flow for a p~riod of 

from ten-odd seconds to several tens of seconds. 

Because an air current was obta1ned at a high Reynolds number with 

this wind tunnel, the gaseous density 1S high when the pressure is 

high. Consequently, in compar1son to w1nd tunnels having the saine 

a1r path cross section area, the same Mach number, and a low 

Reynolds number, the amount of air flow is as large as the 

density is large and therefore, there is a disadvantage w1th 

regard to durat1on. Furthermore, there is even more of a 

disadvantage with regald to the excess blow1ng pressure, Wh1Ch 

will be explained below. 

Duration is found t¥ dN.dlng the amount of alr available ln 

the alr tank by the amount of alr f10w during the Wlnd tunnel 

tests. In the evaluatlons of the amount of air that is 

available it is necessary to determlne 

(a) the amount of alr ln the alr tank from the beg1nnlng 

of alr flow untll normal condltlons are obtained, or that is, the 

amount of alr pressure lost by the a1r tan~, 

(b) and the surplus of a1r pressure inslde the air tank after 

,,', . hO'rm~r cortch tlons "are' hhished. " '. 

These were computed from exper1ment results wlth a settllng chamber 

pressure of 12 kg/cm2 abs. Wlth regard to (a), the ratio of the air 

tank pressure when normal condlt1ons were obtained durlng alr flow 

and the alr tank pressure when alr flow began was 0.85, Wh1Ch 

was somewhat lower than the predicted value (0.9), when the 

Ist-3rd alr tanks were employed (can be adjusted by the control system)· 

However, the ratlo of the settling chamber pressure to the 

air tank pressure when normal cond1tlons were flnlshed in (b), 1.2, 

was much better than the predlcted value (1.4). Therefore,good 

results were obtalned wlth the pressure regulatlng valve. 

The duratlon of normal conditions can be computed wlth this va)ue 

with any experlmental condltlons. Some of these results have been 

recorded in Flgure 10. 

18 
, l 

f 

-.... '-

. /. 

~""_ • ........ __ ......... r_~""'''''''''''*'''_~ ~ _-___ __ ~_'''N-''~--'''''''''''--~~'''''f*''~~- .I A ____ .... __ ... ___ .... __ •• ''' (1 ~"'-~~j" \ I ......---, _ 

.. 

4.3 Precharged Operat~on 

OHlGtNAL PAG!! tS 

OF POOR QUAL1Tf 

As was mentioned in section 3.4, both conventional operations 

for blowoff type wind tunnels and precharged operations are 

possible with th1s wind tunnel. The majority of the tests carried 

out here were performed with the pre charged operation method and 

there were no particular problems. This precharged 

operation method is characterized by the fact that it is 

carr1ed out w1th a high, fixed settling chamber pressure. 

Conventional operation methods cannot be carr1ed out when 

the fixed settlir, chamber pressure is high. 

Therefore, a comparison of the two systems with a relat1vely 

bwsett11ng chamber pressure 1S shown 1n F1gure 12. The 

amount of time unt1l standard cond1t10ns are obta1ned is the 

same with both systems. Moreover, with both systems 

the Mach number reaches standard condit10ns in 1-1.5 seconds 

after the settling chamber pressure Po has reached standard 

cond1tlons. It seems that because the ga1n, integral t1me, 

etc. of the control systems of both methods cannot be adjusted 

to the optImum values, the tranS1ent t1mes shown in FIgure]2 /8 

can be curtailed even further to 1-2 seconds. 

. " ••••• • •••• :;.8 •••• ••••••••• ... .- ',I ••••.••. 

I: 

-, "". .. Ij .. .. ' .. .' . .. .. .. .. .. . ~~ .::& ••••••••••••• •• • i:j • .. • 

• • 

• • I:~ .. • • PRECHRRGE . . MEA,.. (y~105[Cl 0.7143 

• "C~NV[N 10tlnL 

• M AN (5~IOs(cl 0.7134 

~L .. ' , , , , ,00 .00 .oo .oo "00 .oo f/nt U£CI 

.. ~ 

• 

'I: 

~B 

~ .. 

fa 

:t .. • PR~CHA'lOE 

M~ N (~~IOSUI 5.973 • C NVEh, rOtJAL 

M AN (S~IOstcl 5.443 

~I ... , , ,'eo &!oo , , .. , .. . .. . .. flnt I SEC 1 

FIgure 12 • ComparIson of Precharged Operat1on System and Convent1onal 

OperatIon System-I: 

left -- settling chamber pre!,';';ro; 

Right-- Mach number. 

19 

I 

I 

I . 

I 

t 

r.: 
'-, 

' .. - //,;-' 

/ 

....-----

, . 

~ 

" .-- Ll!l .. ,.........:: ......... ~ .. ' ..... - .... "-.! --::..,----: •• ~-... ~~..,....-............,-~~.~~.........-.. .. ~,,~~ ........ -,_-:"'_ .............. ~ __ ~: ~ c. "'" _= ............ , .. ~t.....~ •• -----~- -- - ---•• -. '-' ••• - -~. • - 1~ 

I ):. 

4.4 

., 

• 

ORIGINAL PI\G~ '9 

OF POOR QUALln' 

• • • • 

• • •• 

~I ~It···· ··I •• t!!~ ••••••••••• •••••••• • •••••••••• o '"., . 

~ • PRFCHARGE 

t1~IlN 15~IOml 27.13 • C NVEN TI ONAL 

t1 AN 15~10s£cl 22.61 

11 i , , iii 

•• .... 101 ... ... '" 101 11111: ULel 

Figure 13. Comparison of Precharged 

Operation System and Conventional 

Operation System-II: 

SattJ t ng chamber temperature. 

Other Items 

The following 1tems should be mentioned with regard to 

the operation tests results. 

(a) The t1me necessary for reaching standard conditions 

can' be decreo'Sod '. 'to' 0.5-1 second by employing ~he Mac'll ,number;, 

control (3.4(a». 

(b) It is common for the test area wall pressure distribut10n 

to be uniform. However, when the air flow near the sect10n 

where grooves are employed for the measurlnq probe behlnd the 

downf1ow of the model attachment accelerates, the uniformity of 

the Mach number 1n this reg10n is destroyed. 

(c) The silencer was effect1ve. Sounds from the ,wlnd tunnel 

were e11mlnated at the entrance on the south side, the 

computer room on the west slde, the large, low speed wlnd tunnel 

on the southwest slde, etc. NOlse from the w1nd tunnel was 

heard between the Power Division on the north side and the 

laboratory. However, this noise was probably produced from the 

high pressure duct between the alr tank and wlnd tunnel. 

20 

J 

1< 

I 

I

, J 

.' " .. 

I 

I 

I 

I 

i 

I 

I 

I 1 • 

I 

I 

! 

I 

I, 

,~ 

of 

I 

I 

i 

1 ,I 

I 

I 

, 

• 
( 

." 

, " 

/ 

----

, .. 

, J 

') 

.-.--------------~~----------------------, 

---

-... 

.. 

5. Future Plans 

Tests on the Mach number distribution and stardardized model 

pressure distribution (NACA 64A4l0) will be carried out 

in the last half of 1979. Wing section systems tests will 

begin in 1980. 

In conclusion we would like to express our thanks to the 

2nd Aerodynamic Research laboratory and in particular to 

Supervisor Chuken, and to Kawasaki Heavy Industries, 

Ltd., Ish~kawHjima Hoon Kogyo Co., Ltd., Yokogawa Hewlett 

Packard Co., Ltd., Marunich~ Watanabe Construction Co., Ltd., 

Hajima Construction Co., Ltd., and Angawa Electrical 

Equipment Co., Ltd. 

(2nd Aerodynamic Research laboratory) 

Bibl~ography 

(lJ H~rosh~ Endo, et al.,: Kog~ken Nyusu, No. 218, (1977/7) 

[2J Takew1tsu Sakak1bara, et al.,: Kog1ken Hokoku, TR-465 , 

(1976/7). 

[3J H1roshi Endo: Koku Uchu Gakkaish1, Vol. 26, No. 299 (1978/7) • 

[4J H1rosh~ Endo, et al., : Kog1ken Hokoku, TR-476 (1976/10) • 

, .. , " " ,[~1 f!u:Qshi .E:ndo",.et al. ,.,:, KQgJ:keQ .Nyusu, No. 190, (1975/3): 

, t 

21 

~ 

r 

'j 

i 
End of Document