L!FCJ:\!J:A '!:tJS':'!TUTE OF TECHt!OLOGY GGENHElM AER0NAUT!CAL LABORATORY

JRANDUM No. 29 UTE OF TECHNOLOGY

!f - AUTICAL LABORATORY ------~~----~~--~--~~~

HYPERSONIC WIND TUNNEL

Pasadena, California

MEMORANDUM NO. 29

·'

July 31, 1955

INSTRUMENTATION

OF

GALCIT HYPERSO_NIC WIND TUNNELS

by

Paul E. Baloga

Henry T. · Nagamatsu

IN U

..

. .

•

SPONSORED BY ARMY ORDNANCE AND AIR FORCE

CONTRACT NO. DA-04-495-0rd-19 .

Contract No. DA4-495-ord-19

A.rfn7 Ordnance Department

SponsoMd b,y A:nq Ordnance and Air Force

MEMORANOOH NO. 29

INSTRUMENTATION OF GALCIT HIPER:iONIC Wnm TUNNELS

. Paul E. Baloga

Henry To Nagamatsu

~w-4<&-Guggenheim Aeronautical Laboratoq

GOOGENHEJM AERONAUTICAL LABORATORC Cal.ii'omia Ina t.i t.u t.e of Technology

Pasadena, California

~ .:n, 195S

TABLE OF CONTENTS

PART PAGE

I. Introduction 1

II. Hypersonic Wind Tunnel ~scription 2

A. Leg No. 1, Mach Number Range 2-7 2

Be Leg No. 2, Mach Number Range 4-11 .3

III. Compressor Plant Instrumentation .3

Ao Variable Concii tions Indica ted on the Control Panel .3

le Inlet and Outlet Pressures for Each Stage of Compression .3

2. Outlet Air Temperature for Each Stage .3

.3. Compression Ratio o£ Certain Compressor Stages 3

4. Stagnation Pressure 4

5. Stagnation Temperature 4

B. Description of Measuring and Controlling Ins trurnents and Techniques 4

1. Operation of Tate-Emery Pressure Indicator 4

2. Method of Stagnation Pressure Control 5

3. Air Temperature Control 6

a. Control for Leg No. 1 Steam Heat Exchanger 6

bo Control for Leg No. 2 Heaters 1

IV • Pressure Measuring Methods

A. Low Pressure Silicone Manometer Banks

B. Low Pressure :t-iicromanometer Bank

c. Tilting "U" Tube Micromanometer

1

1

8

9

v. Mis cellaneo'US 10

Ao Carbon Dioxide Concentration Meter 10

B. Schlieren Optical System 12

c. High Pressure Dew Point Indicator 1.3

n. Oil Removal 13

Figures 15

1

I. INTRODUCTION

For the purpose of developing more efficient rockets and missiles

i'or long ranges, it is necessary to acquire basic info:nnation 1n the

hypersonic Mach number range of 5 to 20. To obtain such aerodynamic

infonnation two Hypersonic Wind Tunnels, Legs No. l and Noo 2, have been

developed at GALciT. With Leg Noo 2 it is possible to obtain aerodynamic

information in one-phase air flow at a Mach number ot about 11.

During the early operation of' the Leg No. 1 tunnel at a Mach

number range of 2 to 7 it was necessary to develop various new experi­

mental techniques to obtain reliable aerodynamic infozmation. The

static pressures in the test section varied in the hypersonic Mach number

range from. about 2 to ;t/4 millimeters of mere while the static

temperature was of the on:Jar of room temperature to 1100~. A great

deal or time was spent in developing manometer boards and special valves

and in perfecting new techniques for measuring these low pressures ver,r

accurately. 'lhe initial operation phase or the Leg No. l turmel was

spent in developing adequate hypersonic instrunentation i'or statio pressure,

total head, heating i'acilitles, and a stagnation temperature controller.

In this report. the important instrumentation developed over the

past i'ew years will be discussed in deta.U. The infonnation should be

usei'ul. i'or other groups planning basic research at hypersonic Mach numbers.

2

II. HYPERSONIC WIND TUNNEL DESCRIPTION

The ~ GALCIT S" x S" Hypersonic Wind 'runnels are ot the closed

return, continuouslY""''perating type and are operated altenia.taly by a

eanpressor plant consisting or sixteen compreaaors arranged in a parallel­

series circu:Lt. A sd1ematio diagram or the wind tunnel installation is

shown in Fig. lA, and the control panel is shown in Fig. lBo

In operating these two tunnels, use is made or a variety ot

instrunent devices 1 some tor proper control or the compressor plant and

others tor obtaining w1ni tunnel data under properly-controlled pressures

and temperatureso In this mEillorandum is presented a brief description

ot the instrunents used at this laboratory. Several ot these have been

designed and built at the laborato~ while others are purchased items

which have been moditied tor special applications •

The use or a single compressor plant tor two wind 1llnnels has a

decided advantage over conventional methods since it decreases the shutdown

time ot the compressor plant to a min:iJnumo A portion or this shutdown

ti.me is used for maintenance and repair. During the time when one

tunnel is operating, the other, together with its associated instrument&•

tiDn, is tree tor model installation.

The two wind tunnels are referred to as Leg No. l and Leg No. 21

respectively. 'lhe pertinent characteristics and specU'ications unique

to each are described as .follows t

Ae Leg No. l, Mach Number Range 2-1

Leg No. 1, which is now operating with the nozzle blocks set .for

Mach s.a, is designed .for a maximum stagnation pressure of ~0 psi. n.

3

air ie heated to a maximum or 1tXPr during it.s passage through a steam

heat. exchanger directly att.er it.s exit. £rom the last. stage at canpreeeion.

B. Leg Noe 2, Mach Number Range 4-ll

Leg No. 21 which can be operated up to Mach ll, ha8 a maximum

stagnation pressure of lo40 ~si. The air is heated electrically to a

maximum or gooDr in the stainless steel settling chamber just. ahead of

the th:rnat.. Semi-flexible nozzle plates designed to operate over a Mach

number nmge or 1 to ll have been installed, and the nozzle 1.8 being

calibrated at. the present. timee

III. COMPRESSOR PlANT INSTRlMENTATION

A. Variable Conditions Indicated on the Control Panel

1. Inlet and OUtlet Pressures tor Each Stage of CompreBsion

'Ihese pressures are measured with standard bourdon tube pressure

gages.

2. Outlet Air Temperature tor Each Stage

The outlet. air temperature is measured with standard iron con­

stantan thermocouples and recorded with a multi-point strip-chart recorder • .

3. Compression Ratio or Cert:.ain Compressor Stages

· This ratio is or interest. only men it approaches the design limit

lil.ich 1a speoitied by the compressor manutacturer. The ori tical compression

ratio 1a indicated on a duplex gage or a certain design. These gages haTe

4

two boumon mowments in one housing with their pointer sharta concentric.

'lhe movements are so chosen that the mtio of their sensitivities is

equal to the critical compression mtio of the canpress or under cons ide~

ation. With this arrangement the inlet pressure-pointer leads the outlet

pressure-pointer when the compression ratio is less than critical.

'When the two pointers coincide, the limit has been reached. This "ratio

gage" then pennits the plant operator to ootennine imnedia. tely the margin

or safety for that particular stage.

4. Stagnation Pressure

This pressure is measured with a Tate-Emery indicator which can

measure up to 1.300 psi in four ranges (described separately).

So Stagnation Temperature

Stagna t:Lon temperature is measured just ahead of the throat with

iron-constantan probes feeding into a continuously-recording controller.

B. Description of Measuring and Controlling Instruments and 'lechniques

1. · Operation of Tate-Elneey Pressure Indicator

The multiple-range Tate-Elner;y' 1s shown schematically in Fig. 2.

The operation is as followsa

Carefully regulated nitrogen (2$ psi) 1s brought into the bellows•

extending them against the action of the tension springs (S) 0 Air

pressure (P0 ) entering bouroon tube (A) detlects it together with the

attached flapper (B) in the direction shown. This cilanges the leakage

rate from oritice (C) causing the bellows (D) to collapse because ot

decreased pressure. Spring (E) is a negative position feedback fran the

bellow to the bourdon tube tlapper combination. 1he flapper tinall1'

assunes sane equilibri\U'Il position, giving a unique leak rate ancf a unique

position ot the bellows for each pressure (P 0

)o The def'onned status of

the bellows is transmitted through the rack and pinion (F am 0) 1 thus

giving a unique position ot pointer (H) on the indicator dial.

Bottled nitrogen is used to operate this indicator, thus eliminating

the need for attention to filtering and drying devices, whioh would be

necessary if' the available "house" compressed a.ir were to be used.

2o Method of Stagnation Pressure Control

Constant stagnation pressure, which is necessary for proper wind

tunnel operation, is held by means ot a differential pressure controller

of the type used in the process industries tor f'l.ow control. It is used

in the following manner (Fig. ))a

Air is pennitted to enter a pressure bottle until it is charged

to a pressure equal to the pressure at which the tunnel is to be operated.

At this time a han~ valve (V1 ) is closed, isolating this pressure, which

has been measured with the Ta te-Ernery indicator and which is to be used

as the reference pressure on one side of the controller bellowso The

air pressure to be controlled is brought to the other side of the bellows

and is compared against the reference pressure. When 'there is a pressure

di£f'erence1 the controller actuates a diaphragm-operated valve, venting

more or less air to atmosphere from the system in order to equalize the

pressure in the bellows. Pressures to 'Within .o4 psi are easily hel.d.

6

~· Air Temperature Control

a. Control for Leg Noo 1 Steam Heat -Exchanger

7.he air1 which has been dried with _silica .sel and filtered through

a series of filters consisting of activated charcoal, sintered carbon,

and a special glass filter cloth during its passage through the com­

preseor plant, is then passed through the steam heat exchanger. Just

before ite entrance into the exchanger, a portion or the relatively-cool

air is bled off through a pneumatically-operated valve. 1his diverted

air is then used for finer temperature control by mixing it with the

heated air on the exit side of the heat exchanger.

'!he temperature or the final air is controlled 'by means of a

pneumatic controller incorporating both derivative and integral modes. - -The pneumatic pressure si~al from this controller is a function or the

heat input necessary to keep the stagnation temperature at a pre-set

valueo

The diaphragm valve (Fig. 4), which is actuated w.tth air pressure

from the controller and which controls the steam flow into the heat

exchanger, is connected in such a · way as to be closed with no air

pressure on its diaphragm 'WhUe the valve controll.1ng the cool and heated

air mixture ratio is normally open with no air pn!ssure on its diaphragm.

This mixing valve is also operated by the same pressure signal which

operates the steam valveo In this way they operate in opposite sense,

which d.iminishes the time constant at' the cooling portion or the oontrol

cyele. This feature is or considerable importance due to the large

themal capacity of the steam heat exchanger.

b. Control for Leg No. 2 Heatere

~e compressor plant whicll is used for the Leg No. 1 tunnel is

also used, together with its associated drying and filtering equipnent,

i'or operating the Leg No. 2 tunnel. The air 1n Leg No. 2, however, is

electrically heated 1n the stainl.ess steel pressure vessel just ahead

ot the nozzleo 'lhe same temperatum recorder-qontroller as is used 1n

7

Leg No. 1 is used to control the temperature 1n Leg No. 2. This controller

uses standard thermocouple input, giving a pneunatio signal 1n the fom

of varying pressure as the control output. 1h1s vaeying pressure from

the controller 1s t:mnsfo:r:'JIJ3d into an electrical equivalent signal by

means of a GALOll'-designed transducer (Fig. S) • The transducer consists

ol a diaphragm motor actuating, through a rack and pinion, a variable

resistor, which in tum is used to control a saturable reactor.

Stagnation tempe:mtures in Leg No. 2 have been controlled up to

9000,. ~ 10,., with the use of this control.l1ng technique.

IV. PRESSURE MEASURING MErHOOO

A. Low Pressure Silicone Mananeter Banks

Most of the pertinent pressures in the wind tunnel test section

are measured with 100 em full scale silicone manometer banks designed

and built at this laboratoeye In Fig. 6 the schematic arrangement of tM

reservoir and valving is shcnm, and Figo 7 shows the manometer board.

'l'h1s is a standard reservoir type manometer using the GAWI'l'-design,

three-way- vac\lUtll valve (Fig. 8). When no pressure readingS are l:eing

taken, the valve is in such a position as to expose the liquid column

8

to the same low pressure as the reservoiro ibis reserY'oir pressure is

kept at between 3 and 10 microns ot mercury pressure and 1s checked

regularly' by means of an ionization pressure gage called the "Alphatron•o

This keeps the silicone nuid under continuous vacuum, which is necessar.r

in omer to prevent air from becoming dissolved into the liquido When

pressure readings are to be taken, the valve is adjusted to the position

shown in the figure, which exposes the liquid column to the pressure

being .aasured (Fig. 6).

The silicone liquid used in the manometers is known commercial.ly

as Dow Coming Compound 200e For this application a viscosity rating o.t

10 centistokes is used.

B. Low Pressure Micrananometer Bank

A twelve-tube micromanometer bank has been designed am bullt .tor

pressure readings which require accuracies greater than .2 nun of silicone

(Fig. 9). ibis micromanometer is capable of sensitivity in the order of

.ooS JID1l of silicone. This sensitivity is attained by projecting an

image of the meniscus in the glass tube onto a ground glass viewing

screen, on lbich there is scribed a horizontal index line. The men1sC\l8

and the index line are superimposed by adjusting the elevation of the

projection system by means o.t a moto~ri ved precision lead screw. This

elevation is then read from. the counter, which is geared to the lead

screw to read directly' in incrementa of .01 tnnt. ibe full range of the

micromanometer is 30 em.

In order to improve visibility the a1licone nuid 1s dyed a blue

color by passing it through filter paper on which is sprinkled dye

(Calco oil blue, ZA ex oono. from the American Cyanamide Co., Calco

Chemical Division, Dyestui'f l>epartmmt, Boundbrook1 New Jersey).

c. Tilting "U" Tube Micrananometer

A micromanometer w1 th a range ot one inch has been developed•

This Wlit can use either silicone or mercury with a sensitivity ot ! .oooS in.

(Fig. lO). It is essentially a "U" tube with short legs, which can be

tUted about the pivot (P) by means of a machinist's micrometer head

(M). The manner of operation is as follawsa

Stopcock (S) is tUl"Dad to the position which exposes both liquid

columns to the reference plt!ssure. At this time the micrometer is

adjusted to the "null" posi tion1 which is indicated at the suri'ace ot

the fluid by a distorlion of the reflected light (L). This distortion

i.e caused when the point of the "catwisker" pierces the meniscus ot the

manometer fiuide 'lhis "piercing point• is quite definite and can be

repeated to within .oooS inche This "null" posi ttcm of the micrometer

1s recorded as the ntference level. The stopcock is then turned to the

altemate position \tlich exposes the liquid colUmns to the reference and

the unknown pressure, respectively. The micrometer is again adjusted for

the new nullo The difference in micraneter readings gives the head (h)

of manometer liquid. (.oooS in. of silicone 1s equivalent to oB microns

of me rcur;y •)

10

V • MISCELLANEOUS

Ao Carbon Dioxide Concentration Meter

Since carbon dioxide acts as a nucleant tor air condensation when

it ie present in quantities greater than a certain critical amount1, it

ia of interest to monitor the co2 concentration,, particularly in Leg No.

2, 'Where it could possibly build Up due to the burning of small oU

particles as they pass through the electrical heater vhUe being carried

through the air stream fran. the compressor plant. With this in mind a

continuously-sampling a~er vas designed and built. (Fig. 11)

Operation of this analyzer is based on the fact that the quantity­

of carbon dioxide dissolved in water is proportional to its partial

pressure in the gas mixture to be analj"zed.

'Wh.ere

co • 2 22.4

co2 • concentration of dissolved carbon dioxide

p co2

• partial pressure of carbon dioxide in atmosphere

Carbon dioxide -bicarbonate equilibrium reactiont

To measure the hydrogen ion (ph) concentration an indicator ia

tiSed 1n the solution, in this case bromo-teymol blue. The color range

of this indica tor is trm yellow on the acidic side to deep blue on the

1. "Effects of Impurities on the Supersaturation of Nitrogen in a Hypersonic Nozzle", by' P. D. Arthur and Ho To Nagamatsu, GALCIT ~arsonic Wind Tunnel Memorandum No. 1, March 1, 1952.

u

basic. 'l'he ph or the indicating solution is adjusted, before measurementa

are taken, to tall sanewhere between the two extremes, that is, men the

bromo-t~ol blue appeare greenisho The~ ~ust.ing a elutions

used are very dllute solutions or hydrochloric acid and sodium hydroxide

and. are made while either the standard air or sample air is bubbled

through the solution.

When equUibrium has been reached, an approximately equal amount

is poured 1nw the bubbling cells, 1n 1his case consisting o! two

pyrex test tubes.

'lbe detennination ie made ae tollowsa With Valve 3 opened to

pennit the standard. air to bubble through one ot the cells and Valve 2

opened to bubble the sample · air through the other cell, an observation 1s

made or the colors or the solution. With sample air containing a greater

percentage of co2

than the standard air, there will be brought about a

color mismatch. Valve l is then adjusted untU the sample air is

properly diluted to bring about a color balance. From the calibrated

!lowmeters a ratio or dilution can be secured. With this ratio and the

known concentration or carbon dioxide 1n the standard. air, the concentra­

tion in the sample air can be computed.

The standard air can be made up tor special concentrations, or

ominary outdoor atmospheric air can be used tor measur.t.ng in the mnge

of .o)% concentration or co2• Many investigawrs have found outdoor

atmospheric air to contain between o03l and .032% carbon dioxide, this

figure being constant over various part.s or the country.

It has not been dif'ticult to sense 70 parts per million of co2

with visua1 color canparison in the test tube cells. '1h18 represents

approximately .1 ph change. Obvious~, when more sensi t.ivity ie required,

12

other methods of ph measurement are required, that 181 precision optical

and photoelectric colormeters and electronic ph metei'IJ"

Bo Schlieren · Optical System

'l'he schlieren system is a conventional 11 Z" configuration with

traversing nate which can be controlled from the camera sight, (Ffg. 12).

This pennits rapid monitoring of the complete length of the test section

through a series of glass ports which are spaced at regular intervale on

the sidewalls •

The pertinent specifications of the schlieren system are as

tollowst

Spherical Mirrors

f.lo 120 inches surface t 1./4 ~ dia. 8 inches

Flats

Lamp

surface t 1./4 " dia. 12 inches

General Electric BH-6 high pressure mercury vapor air cooled

Slit Size

l tTIIl x S tTIIl (nominal)

Film Size

4" X 5"

Shutter Speed Range Available

1./400 sec •••••••• 1 sec.

13

o. High _Pressure 11ew Point Indicator

The dew point indicator show in Fig. 13 baa been designed for

Measuring the dew point at air at pressures up to 1000 psio · It is of

conventional design using the cooling e.f'fect of carbon dioxide which is

expanded against the rear of a chromium-plated ndrror. The temperature

of this button is read at the tilTle that dew deposit 1s observed through

the window. \tlt1h the t91Tlperature and pressure known, the specific

humidity can be computed or read directly off the c~rt (Fig. 14).

Do Oil &moval

During the nonnal operation or the canpressor plant which is

used for operating the 'bro wind tunnels, oil or the order of 1 quart per

hour is added to the air e tream. Removal or this large amount of oil 1s

accomplished by a series of different types of filters.

After each compressor there is a vortex type or .filter, commonly

called a cyclone separator, which ·removes the largest part of the oil.

Next, all or the air passes through an impingeMent filt.er made up of

~anisters filled with absorptive, activated charcoal (cocoanut shell),

which also removes oil vapom. It is believed that the oil at this point

is in the fonn of droplets, and the air is passed through two different

porosities of sintered carbon blocks* 1" thick1 which take out drops over

10 microns in diameter.

The final stage of filtering is done by a corrmerical.l.y-manufactured

fiberglass paper manufactured by the Mine Safety Appliances Compaey•**

* National Carbon Company, 30 East 42nd Street, New Yorlc 17, N. Yo

** Mine Safety Appliances Company, Braddock~ Thomas~ and Meade Streets, Pittsburgh 8, Pennsylvania0

The Mo Sa Ao filter, called "Ultra-Air Space Filter", comes as a unit

read7 tor installation. This filter 1B unconditionally guaranteed to

be 99.9S% effective against particles .3 micron 1n diameter with a

pressure drop of l inch of water. It has been 1n use at this laborato17

for one year, passing 6o pounds of air per minute at a velocLty ot 55 rt.

per minute and has required only three washings to date. lhese washings,

using carbon tetrachloride, were cbne when a pressure drop of two inches

of water was indicated across the filter.

I I I I I

L----..g-----J

2.

LEG NO.I

LEG N0.2 TEST SECTIONS

~.

L ____ j _____ ~~-~~~~------J

':1 v 1

SCHEMATIC DIAGRAM

STEAM HEATER

s

OF GALCIT 5x5in . HYPERSONIC WIND TUNNEL INSTALLATION

FIG. lA

DROPLET FILTER

6

3 VAL.l/ES

a MOTORS

• COMPRESSORS

-~ 7

~

'i ~ ~fwlr.. TJ.. (Q

f!.w r Ov ci- 1 ) •v.io!fn, ,.(lfh.t..i. c~d ,

E

-D·BELLOWS

NITROGEN

SCHEMATIC OF TATE-EMERY PRESSURE INDICATOR

FIG. 2

17

P.

Po

TATE-EMERY

V1-HAND VALVE

DIFFERENTIAL PRESSURE CONTROu.ER

PRESSURE BOTTLE (Rated 2400 psil

TO

DIAPHRAGM VALVE INSTRUMENT AIR (STAGNATION VENT)

SCHEMATIC OF STAGNATION PRESSURE CONTROL METHOD

FIG. 3 ~

~~

L.c::: COOL AIR

~ .z-~~" ((-:! . J:)L

~r--

' ~~ \.\(ffi~

~ STEAM HEAT EXCHANGER~

-Lbtl

TEMPERATURE 7 CONTROLLER

®

\_;I ~ '[[Jr-DIAPHRAGM VALVE

NORMALLY OPEN b.-., HEATED AIR

j DIAPHRAGM VALVE II CO~DENSATE NORMALLY CLOSED OUT

l

CONTROL AIR LINE

:;> 16) 01==~ INSTRUMENT AIR

SCHEMATIC OF LEG NO. l TEMPERATURE CONTROL FIG. 4

':) ~· I

STEAM IN b..J ~

AIR

IN

300 KVA MAXIMUM

•

CONTROLLER

DC SATURATING 3-PHASE I CURRENT CHASSIS

SATURABLE REACTOR

HELl POT

O}}»k«dih. HEATING GRIDS

ELECTRICAL HEATER SHELL

SCHEMATIC OF LEG NO. 2 HEATER CONTROL

FIG.5

0, c*

INSTRUMENT­AIR

THERMOCOUPLE PROBE

~

TO TUNNEL

TO ALPHATRON

TO VACUUM PUMP

RESERVOIR FOR SILICONE

MANIFOLD

GALCIT 3·WAY VACUUM VALVE

READING TUBE

REFERENCE TUBE

SCHEMATIC OF SILICONE MANOMETER FIG: 6

21

r

FID.7

NAN<l-1E'IER BOARD

Fm. 8

IJJW PRESSURE VALVES

22

23

r t l .. . . ' ' ' ~ \

.. . \ \ . " . \ \ .. . • . ., \ \ \

. '•

~ . . \ \

. . ·., \ ~\ '" .... ,, ....

·~ .. .. ~\

~ ' 1( ·~

FIG. 9

12-TUBE MIC l{)MAtnlE TER BANK

REFERENCE PRESSURE

NKNOWN PRESSURE

GLASS CATWHISKER (C)

HIGH VACUUM, MERCURY SEAL STOPCOCK

(S)

MICROMETER HEAD {M)

SCHEMATlC OF TILTING U-TUBE MICROMANOMETER

FIG. 10 t?-

FLOWMETER

UNKNOWN AIR SAMPLE

0

NEEDLE VALVE NO. 3

FLOWMETER

BUBBLING . CELLS

NO. I

NITROGEN {FREE OF C02 )

CARBON OIOXI DE CONCENTRATION METER

FIG. II

1\) \J'l

ACHROMAT ,..--LAMP

r---12 11 FLAT

a• SPHERICAL MIRROR

I - 8" SPHERICAL MIRROR I I

N _ _ -r - -~ j _________ ill:2::~:==:::::=--l ,, I ' ' ',,-.) __ -- - : ""\.

'->

SCHEMATIC OF SCHLIEREN SYSTEM FIG. 12

\\_SHUTTER

\_KNIFE EDGE

VIEWING SCREEN a CAMERA

&;

VALVE NEEDLE

SAMPLE AIR .,

SEAL

MIRROR BUTTON

SCHEMATIC OF HIGH PRESSURE DEW POINT INDICATOR

FIG. 13

PIN

N ~

>-1-0 -:E :::>

---DEW POINT --FROST POINT

psig J4.7-;-, 50

100 150

I 200 :)f'\ \ \:;.,-4 ......,..,.,..........-~,...;.............:::;:::>' 1~1 I I ~ ~

:I:I0-4 1 I .- ..c1 r..c ..:;;.~ -:::;-e: ~~ "F .,......- I I 7 7 / >'_/"/=~ .>-~ :.;;r :,;7

(.)

u. (.) w a.. (/)

300 ·-400

.~ I \ \l~~g +----------4

-40 -20 0 20 40 60 TEMPERATURE (°F)

SPECIFIC HUMIDITY VS. DEW POINT TEMPERATURE AT VARIOUS PRESSURE LEVELS

FIG. 14

80

N (X)

CALIFORNIA INSTI'J.Ul'E CF TECHNOIOOY HYPERSONIC WIND TUNNEL

CONTRACT NO. DA-d.J-495~rd-19

REPORl' DlSTRIBUTION LJBT

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Mro Bernard F. Jaeger Head, Ac rodyna:nics Branch u. s. Naval Ordnance Test Station Inyokern China Lake, Cal.ii'omia

Conunander Western Development Division Post Office Box 262 Inglewood, California

Armed Services Technical Information Agency (5 Copies)

Document Service Center Knott Building Dayton 2, Ohio AT'l'EHTIO!l : I:SC-8D22

National Advisory Cormdttee for Aeronautics 1512 H Street, Northwest Washington 25, D. c. ATTENTION: Aerodynamics Branch

Mr. John Stack Associate Director of Research National Advisory Conunittee for Aeronautics Langley Memorial Aeronautical Laboratory Langley Field, Virginia

Dr. John c. Evvard National Advisory Committee for Aeronautics Supersonic Propulsion Division Lewis Flight Propulsion Laboratory Cleveland, Ohio

Mr. H. Julian Allen National Advisory Conunittee for Aeronautics Ames Aeronautical Laboratory l1offett Field, Cali.forraa

Library Institute of the Aeronautical Sciences 2 East 64th Street New York 21, N. Yo

ARO, Inc. Post Office Box 162 Tullahoma, Tennessee

2

General Electric Company Reports and Docunents Division 2900 Campbell Avenue Schenectady 5, New Yolk

Ramo~ooldridge Corporation 8820 Bellanca Avenue Los Angeles 45, California

RAND Corporation 1700 Main Street Santa Monica, California ATTEtiTION: Miss Hargaret Anderson,

Librarian

Sverdrup and Parcel, Inco Syndicate Trust Building St. Louis 11 Missouri

Mr. E. E. Clai'k Chief of Aerodynamics Glenn L. Martin Company Baltimore 3, Maryland

Hr. A. Flax Head, Aerodynamics Research Department Cornell Aeronautical Laboratory, Inc. 4455 Genesse Street Buffalo 21, New York

Mr. Martin Go land Director for Engineering Sciences Midvrest Research Institute 4049 Pennsylvania Kansas City 11, Hissouri

Dr. Henry To Nagamatsu General E)e ctric Company Research Laboratory Schenectady, New York

Dr. Allen E. Puckett Hughes Aircrai't Company Culver City, California

Hr. E. Williams RAiiD Corporation Hissile Aerodynamics Section 1700 Main Street Santa Monica, California

Distribution List

Professor Harold o. Barthel University of D.l.inois Aeronautical Institute Urbana, Illinois

Professol' R. c. Binder Pumue University Laf'ayette, Indiana

Professor L. M. K. Boelter University of California Engil1eering Department Los .Angeles 1 California

Dr. Seymour H. Bogdonort Princeton University Department of Aeronautical Engineering Princeton, New Jersey

Professor Sin-I Cheng Princeton University Depart.ment of Aeronautical Engineering Princeton, New Jersey

Professor Francis Clausal' Johns Hopkins University Graduate School of AeronautiC& Baltimore, Maryland

Dro R. Courant New York ·University New Yorlc, No Y.

Profesao r Ho W • &Intone Harvard University Department or Applied Physics Cambridge 38, Massachusetts

Professor R. J o Emrich Lehigh University Department of Physics Bethlehem, Pennsylvania

Professor Antonio Ferri Polytechnio Institute of Brooklyn Ae J.'Odynamics Labo ra.toty 527 Atlantic Avenue Freeport, New Yorlc

Dr. R. G. Folsan Director, Engineering Research Institute East Engineering Building Uni-versity or Michigan Ann Artx>r, Michigan

3

Dr. R. Paul Harrington Rensselaer Polytechnic Institute Aeronautics Department Troy 1 New York

Dr. ~olph Hennann Department of Aeronautical Engineexlng University or Minnesota Minneapolis l4, Minnesota

Professor A. M. Kuethe University of' Michigan Aeronautics Department Ann Arbor, Michigan

Dr. Ting-Yi Li Rensselaer Polytechnic Institute Aeronautics Department Troy, New Yortt

Dr. c. c. Lin Department of Mathematics ~mssachusetts Institute or Zachnology Cambridge, Massachusetts

Professors. Io Pa1 Institute of Fluid Dynamics and

Applied Mathanatics University of Maryland College Park, MarylaM

Dr. Ronald F o Probstein Brown University Division or Engineering Providence, Ro I.

Dr. s. A. Schaaf Associate Professor or Eng. Sciences Low Pressures Research, Inste ot &lg. Bee. Engineering Field Station 1.301 South 46th Street Richmond, California

Dr. w. R. Sears Cornell University Graduate Sehool of Aero. Fngineer'ire Ithaca, New York

Professor H. Guyf"onl Stever Massachusetts Institum of Technology Aeronautical Phgineering Department Cambridge, Massachusetts

Professor Ro G. Stoner fennsylvania State University !'hyaics Department State College, PennsylTania

Distribution List

Dr. M. J" Thompson Defense Research Laboratory University of Texas Post Office Box 8029 Austin 12, Texas

Professor Gavin L. von Eschen Ohio State University Aeronautics Department Columbus 12, Ohio

Dr. Th. von K!rm!n 1501 South Marengo Avenue Pasadena 5, Califor.nia

Jet PropulB ion Laboratory Californi a Institute of Technology 4800 Oak Grove Drive Pasadena 2, Califo mia AT 'IEN.l'ION 1 Reports Group

Dr. P. \vegener Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove . Drive Pasadena 2, California

Dr. H. s. Tsien Jet Propulsion Center California Institute of T

8chnology

Pasadena 4, California

Aeronautics Librar.y California Institute of Technology

Dr. Clark B. Millikan (2 Copies) Dro Julian D. Cole Dr. Donald E. Coles Dr. P. A. Lagerstrom Professor Lester Lees Dr o H. W. Lie}Illa.nn Dr. A. Roahko California Institute of Technology

Hypersonic Design Group Hypersonic Experimental Group Hypersonic Theoretical Group Hypersonic File California Institute of Technology

TOTAL • 82

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