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~EDC-TR-61-12 ARCHIVE COPy DO NOT LOAN / m ~_m ~r~ ® @ THE EFFECTOF RECOMBINATION RATE ON THE FLOW OF A DISSOCIATING DIATOMICGAS By Thomas P. Anderson Gas Dynamics Laboratory Northwestern University Evanston, Illinois September 1961 AF~ UM~RV ARNOLD ENGINEERING DEVELOPMENT CENTER AIR FORCE SYSTEMS COMMAND ® @ us ,F
Transcript
Page 1: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

~EDC-TR-61-12 ARCHIVE COPy DO NOT LOAN

/

m

~_m ~ r ~

®

@

THE EFFECT OF RECOMBINATION RATE ON THE FLOW OF A

DISSOCIATING DIATOMIC GAS By

Thomas P. Anderson Gas Dynamics Laboratory Northwestern University

Evanston, Illinois

September 1961

AF~ UM~RV

ARNOLD ENGINEERING

DEVELOPMENT CENTER AIR FORCE SYSTEMS COMMAND

®

@

us ,F

Page 2: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas
Page 3: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

A EDC-TR-61-12

THE E F F E C T OF RECOMBINATION

RATE ON THE FLOW OF A

DISSOCIATING DIATOMIC GAS

By

Thomas P. Anderson

GAS DYNA/W/CS LABORATORY N o r t h w e s t e r n Unive r s i ty

Evanston, I l l inois

(The r ep roduc ib le copy supplied by the Gas Dynamics L a b o r a t o r y , N o r t h w e s t e r n Unive r s i ty was used in the reproduc t ion of this r epo r t . )

Sep t ember 1961

The r e s e a r c h r e p o r t e d he re in was p e r f o r m e d at N o r t h w e s t e r n Un ive r s i t y under Arnold Cente r sponsor sh ip .

P r o g r a m A r e a 806A, P r o j e c t 8951, T a s k 89104

Cont rac t A F 40(600)-748

AF - A I E : D C Armed # , M

Page 4: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

ABSTRACT

The f low of a chemica l ly r e a c t i n g p s through a d iTe rgen t noss l e

Is considered. £ pure diatomic gas i s assumed to d issoc ia te and reoom-

b/he acco rd ing to seven d i e t i n c t recombinat ion r a t e lawe. The e f f e c t of

a o r r e o t i n g L t g h t h i l l ~ 8 " i d e a l d i s s o c i a t i n g gas" f o r v i b r a t i o n a l o o n t r t -

bu t l o r ~ of the molecu la r epec t e s and t r a n s l a t i o n a l c o n t r i b u t i o n s of t h e

atomic spec i e s i s sheen to be s m a l l . The e f f e c t of r e c c = b i n s t i o n r a t e

on the f l o v of o x y ~ n s from t h r o a t c o n d i t i o n s of 2 a t : and ~050 K W i s

shown to he s i g n i f i c a n t f o r r e a c t i o n r a t e s dec r ea s ing wi th tempera ture

and m l a t t T e l y u n t ~ o r t a n t f o r r e a c t i o n r a t e s i n c r e a s i n g wi th t e e ~ e r a -

t u ~ , E l e c t r o n i c ana log computer s o l u t i o n s a re p resen ted f o r a v a r i e t y

of t h r o a t eoapos i t~ons and recombinat ion r a t e s .

t i

Page 5: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

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Page 6: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

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Page 7: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

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Page 8: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

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Page 9: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

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Page 10: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

I , INTRODUCTI~

Deunds fo r tmpr~ lng the performance of chemical rocknt8 n e c e s s i -

t a t e the use of high erMFa p rope l l an t J with msul t inE higher temperature

md~a~t p z ~ u o t s , The analTst8 of these high energy flow streams becomes

tnomasinSl~ nozw d i f f i c u l t as the tonpemture Is l~ tNd~ sines rea l Ks8

e f f e c t s beoo~ noz~ pronounced and there i s s t ~ n i f l o a n t dee ta t lon from

the e ~ s s t o a l 1deal gas behavior. Therual phononons l ~ l a t i ng to the

v i b r a t i o n a l and olect1.onlc energy l e v e l s as w12 as cbmmloal phenomna

r e l a t i n g to the d i s s o c i a t i o n and the ~ontsa t ion of the d t f f e : e n t species

must be considered. The r a t a of ohan~ of the var ious f l o e p a r a m e k ~

muet be c r i t i c a l l y eummlnod to detezwtno uhotber o1" not equi l ibr ium h u

been N c b e d j and OWeD model.ere olmn8oo Such 88 mtsht be found in the

ezpane£on of a pure gss through 8 b:Vporson4c noss le of ten r e s u l t in non

oqu£11hrlua f l o v oond£tions. Those non equ£11briun f l o w arc p a r t f e u l a r l y

lw?or tan t fo r r e a l reasons , In order to e r m i n e the problem of aero-

dynamic heat iug of : e - e n t r y Tehtcleap the flow condi t ions of the a i r

pass ing through tlw bow shook must be known, Aleop non e q u i l i b r t u a f l o l

mast 13o p n e ~ t e d in t e s t f a c i l i t i e s to simulate these : e - e n t r 7 cond i t ions ,

The t h r u s t of s rocket engine Is s e r i o u s l y a f fec ted bb" the ex t en t to

vhioh the propo~.ant to d i s soc ia ted a t the noss le e x i t and consequently

how e f f i c i e n t the engine has been In oonTert ir~ the chemical ene1.By ~o

k/aer ie oneFiD',

- 1 -

Page 11: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

2-

~rs (Reference 1) ~ uas among the first to eezTeet ideal gasas

to compensate for real gas effects. He umd Berthelot's equation of

s t a t e to aoeount fo r the mleou la r 8ise and i n t e r m l e e u l a r forees as

w l l as a Planek t ens to g t w changes in the v i b r a t i o n a l heat eapaeit les.

b then anal~ed a nuabor of one diaenelonal f lows of a dtatoaio gas~

f ind ing t h a t these inpe r feo t gas cor rec t ions beeam s / ~ n i f i s e n t f o r

pera tures eorresponding to the FAov through a shook maw at a Huh

number of 10o Chem~oal roaot iono ms~ not oon~des~d.

Tlw problJm of a obmioal~y m a s t i n g gas f ~ throuzh a n o a ~

has been examined by Edse (Reference 2). In th is 8tudyp the Bases w~e

asS,reed to be in a s t a t e of porfeot thennodynsnic and e~enies l e q u l l i -

brims a t a l l tSJnos and an ef fec t i ve £sentdroFle exponont m detinod tot"

the f e a s t i n g n tx tu r e . E q ~ ~ r ea l gas e f f e c t s haw also been son-

stdered by Kriolmon and Cmkmol'o (Referenoe 3) and Sing (Refelqmse la).

L-iekson has ~ d the flew of a i r and presents a nuaher of sha f t s

f o r the equilAb~Am proper~ims. Eing has 8 tud~d the t h e o r e t i c a l pets

f o r ~ n ~ f o r an e q ~ b r i u s~xture of n o r s s l ~ r o p n during an l s e n -

tropio ex~ion. Waiter (Referenee 5) has included beat additlen to a

r eac t ing f l ov v l t h the hypothesis t h a t the flow i s in t h e n w d y n a a ~

equ i l J .b r£~ a t every po in t .

A l inear~sed t reatment of m a s t i n g nossle f lew i s E lwn by

Pennor (References 6 and 7) , This approxlJnate ans lTs is i s then applJLod

to the tuo extreme cases of very f a s t r s e o t i o n s , near equi l£brluu

RefereMes are l i s ted i n the Bibl touaphYp Appendix A.

Page 12: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

f l ay , and v e t olov r e n t i o n s , neer L~rosen l~_ov. H~Lms (Refaranne 8)

~resants a d£acuesion of the various these-leo oonom-ni~ the o~gen

recombination ra ts and also an approximate so lut ion fo r one dimensional

channel f l o v . Dot~Lled meet nuaez'2oal solut ions are presented bY

Br87 (Refe~acoe 9), He considered a L t g h t h t l l "1do81 d4oaociattng

gun and solved several specific cues aa we l l 08 presenting an

approximate method fo r the so lu t ion of the oct of go~mz'~g equat ions.

In a l l except one case he asouaed the reooubtnat ion r a t e ulw eooen t l a l l 7

oons tac t . Later Bray (Reference 10) continued these otudlso audp a l -

though he diooussed the temperature dependence of the recombination

r a t e , oontinueo to use a constant r a t e for most of h is ca lcu la t lono

( t h i s g r e a t l y s l s rp l i t l e s the already complicated ana ly s i s ) . Freeman

(Ro£erenee l l ) has pointed out that, th~s assumption t s doubtful but has

presented only, seu~ oonolusive arguments. In l~Ls l a t e r paper Bray a lso

oon81dm the e f fec t o f nossle contour upon the d e a r i e s ~ou equtl4bl~un

ooupos:Ltion. Re concluded from h~Ls approx~ate c a l c u l a t i o n that there

ere nossle oontmws tha t v t l l have a tendency to keep the coapositLon

close to equ~14bz~um but, in genera l , ably are qu£te long and thez~fore

:Lmpranttoal. AddittLonal ana ly t i ca l attack8 on the nosale f low problem

8re given in References 12-20 4noluAtng a number o f nume~osl oolut~Lona

for par~louler cases .

Wogener (References 21-2)) has conducted a se r i e s o£ i n t e r e s t i n g

exper~ente concerning the f log o f a react ing g u mixture o f n~tl~gan

d i e . d e and ni trogen te t rox lde ca r r i ed in u l t rogen. This p a r t i c u l a r

n txturo changu co lor as the r eac t ion proceeds (ni trogen dlozLde i8

bl~rn and ni t rogen tetroxLde i s co lo r l e s s ) allotting concentrat.ton

Page 13: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

smasuremonts to be made by l~ght absorp t ion t s e h n l q u u . S tud ies of both

supersonic expansions and flow through shook waves have bean madsj and

the zwsul te agree m11 with t h e o r e t i c a l pa.ldletlons.

B. S t a t e ~ n t of the Problem,..

This study concerns the e f f e c t of the r a t e of r e ® a b i n a t i o n on the

expansion of a d i a toE te gas. I t wi 11 be assumed t h a t t he va r ious e r m r u

modes are not coupled and t h a t the s t a t e of the gas can be de f ined by

the i d e a l gas law i f con~ensat ion i s provided f o r the Ro leeu la r weijh~

changes as a r e s u l t of the chemical r e a c t i o n . T rans l a t i ona lp r e t a t i o n a ~ B

and v i b r a t i o n a l aodes of energy w i l l be ino luded! h o m v e r , alA the e l e o -

t r o n i o energy l e v e l s w i l l be n e g l e c t e d . An a l g e b r a i c form f o r the recom-

b i n a t i o n r a t e w i l l be assumed and s o l u t i o n s obta ined f o r a number of t i l t -

feawnt r e e e a b i n a t l o n r a t s f u n c t i o n s .

Page 14: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

XX. O 0 ~ O EQUATIONS

A. One Dinsnolonal Invincld Conservatle~ Equations

This Invastf4stlon mill consider eu~y one dinonslonal flow along

e

a otrea~ eoerdina~e, r p in a right handedp orthogonal, eurvilinear

eoovdlnate 8ystom. In the abseneo of sources or sinks the steady state

d

c o n t i n u i t y equa t ion i s

- nags d e n o i t y

a - flow awu

V - vslool

Begleoting eleotrcmagnetie effeets and body forees~ the momentum equation

- - "~ - - "-- 0

p - p11880X~

For adlabatle flow the energy equation is

ar

H - e n t h a l ~

I I 11

Although a l l 8yBbols a r e Inc luded in Appendix A. Nomsnelature s t hey m de f ined as t hey a r e In t roduoed in the t e x t .

Page 15: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

B, Auxil£ar7 Equations

i . Thermodynm~o Relat ions~tps

Only d~atosttc gasos ~ be conm4dored Lu th£s studyp and Lt ~ l l

be a s e ~ o d t h a t thoro i s no tn toraot ionp or oouplJ~K~ bo~uoon the v a r i -

ous onorsy nodos. Tboroforo~ the p a r t i ~ o n funot£on~ Q~ f o r oaoh d i a t c ~ o

moloeulo may be ~ £ t t o n as the product of ths i nd iv idua l p a r t i t i o n funo-

t i o n s fo r tbo t r a n s l a t i o n a l # v£brat ional# ro ta t iona l~ and olootron:l.o

• lodo8 s Oa"

Q ~ ~ t v a ~ 3

S i L t l a r l y s the p a r t i t i o n func t ion fo r each atom i s

Tho l a s~ form in t h i s oxpross~on se t s t ~ roforonco l e v e l t hn t i s eho~n

fo r the onergy zero f o r the atoxLo spocies a t the seam lowsl as fo r the

molocular s p o t . u ,

I t w i l l be fu r tho r anumod t h a t the compommt8 of the p a r t i t i o n

function8 max be adequately s ~ p s ~ N n ~ d by

1 - t

I s " I kT I

Page 16: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

Q ¢lzc - (~

-7-

a - p e r t l o l e mass

k - D o l t m a n u ' s e o n s t a u l

T - a b l o l u t e t empera tu re

h - P l a u o k ' s oons tan t

Y - to ta l volmo

- ~ a m a t 4 r t s t t o f~K luen~ of m l e o u l a r v i b ra t i on

I - moleoular moment o f ~ t A

- r a t a 7 f a o t o r

II - I t a t J J t i o a l m i e h t ( e l e e t a ~ d e p n o m e y ) of the eloet.Yonio

ground s t a t e

g - d i s s o c l a t l o n omrgF

The p a r t l t l o n funo t lono f o r the molsouleo and a t o ~ m t h e r e f o ~

The p a r t i t i o n funo t ion f o r 8 oo:Lleotion of N part, toloo t0 given by

QN N!

The f a o t o r ~ a l in n e o e u a r 7 b e m u s e i n the d e r i v a t i o n of the t e a n e l a -

t i o n a l p a r t i t i o n fvnot$on i t w u assumed t h a t the I n d i v i d u a l p a r t t e l e o

Page 17: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

-8-

se re d i s t i n g u i s h a b l e and tho¥ are no t . Noep a l l o~ the ~hez~odymmio

fune t iono may be de f ined in terms of the p a r t £ t i o n fumotion and i r e d e ~ v a -

t i v e o . ( I t i o c o n w n t e n t to choose N oqual to Av&gadroeo nm~oF and uOe a

molar benin f o r these oa leu laUono, )

The Helmholt, s .~rse energy may be u r i t t e n an

T ~ p r e u = and tho entropT a m r e l a t o d to the p a r t i t i o n f m ~ t l o n bF

The on~halpy may be m ~ t t o n u

H

and the Oibbe f rse e n e r ~ ao

A l t h o ~ h oomo of the r e o t r i e t i o n o i n h e r e n t i n the aoaumptiorm

rolatta~g to tbe p a r t i t i o n func t ions e i l l booomo o]:~ioml or ~ l l be

examined in g r e a t e r d e t a i l in the fo l lowing see t io rm m more oxtonel lm d t s -

cuosions of these i t u m may be found in References ~ and 2~.

2, Equatlon of S ta t e

Uotng Ster l£ngeo approximation f o r the f a c t o r i a l o f l a rge numbers

Page 18: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

9-

the Belahol t s ~rree energ7 may be wr / t t en

and the psrtLsl pressure exerted by the molecular or atoato opeotes Is

_ R T

V BmnrLtlng in terms of m s dens i ty and adding the p a r t l z l p r e u u r o s of

the ~uo a lx tu r e eoaponen~mj the to~al pressure beeoms

In uhloh Ls defined so the nun fmo~lon of the dlsmetated npeetes

Znape~Lon ot Bquat, Lon (2~ ) show that t t 4,, the eluerJ.oel idea3. Ires

equation ot state utth the noleoul~ might oomotod for the l - , o

£mold.on of the diosooLatod 8peoLeo.

CmbJ~Lng termsj the on ' ,~p7 of eLt l~r opoelos may be m~Ltt4n

The on~34~Loo of the a ~ o and m l o m ~ a r opoc~o m therefore

Page 19: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

- i 0 -

,P..T

Rewrit ing in t o m s of mass on, to and adding the cont r ibu t ious of both

eomponentmj the en tha lpy of the m / x t u ~ i s

j, ,E-

Tha d s s r u of approximation in the ea l eu l a t l on of the sn tha lpy m~

be seen by ~ I n l n g P i ~ s 2- I and 2-2. Using the da~a of Bsins

(Reference 26)j the con t r ibu t ions of the various energy modes are shorn

f o r molsoular and atom~o oz~gsn. £1though the o l so t ron le p a r t l t l o n

funot lon has been assumed equal to i t s ground e t a t l e t l o a l vmight and

thus the o).oo~.-'onio onex'lgV has boon nogloatsdp th is r e s u l t s i n only a

ne~1.t~Ibls amount of e r r o r . ~ho e l s o t r ~ l e con t r lbu t lon to the onthalpy

of molsoular oxygen Io more o i ~ f l e a n t j o s p s c l a l l y a t the hlgho~

t smpsmturesI h o ~ r . d l s e o e l a t i ~ deareases the ooncentret ton of the

so l eou l a r opseiso a t h igher temperetureo and oonsequently the e l e e t r o n i e

energy of the moloeuiso may almo bs neglootsd without o~gntf ioont e r r o r .

Almost without oxeeption~ o ther LuvestSgators have used the model of a

d i s s o c i a t i n g gas proposed by L i g h t h i l l (Reference 27).

Page 20: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

60

I

m

!

o m

X

,=

o =

n - ILl n

> - n _1 < "1- I - - Z I.d

50

40

30 ~ r

20

I0

EA

0 0 I 2

FIGURE 2-1

ELECTRONIC

,Tj

f

L

3 4 5 0 6_ 7 8 TEMPERATURE °Kx I 3

ENTHALPY OF ATOMIC OXYGEN

9

Page 21: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

I

I

6 0

50 I 0

x , v o

4O I.d ._1

U ILl _1 o 30

Ilg W Q.

20 ) - Q. ._1

- r

z I0 W

0 0

ELECTRONIC ~ , ~ CONTRIBUTION

J

f

7-. T

2 :5 4 5 6 7 8 TEMPERATURE °K x I0 -3

9

FIGURE 2-2 ENTHALPY OF MOLECULAR OXYGEN

Page 22: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

-1J-

Equation (2-6) correc ts L igh th i l1 ' 8 " ideal dtasootating l~m"

through the fac t that i t allows a var ia t ion in the v ib ra t iona l enea'ey

of the molecular species and the t r a n s l a t i o n a l e n e r ~ of the dtseocia tod

8pe e l se .

h . F, quCl.ttn'iua Coutant

The equi l ibr~ua constant based on p a r t i a l prsseu.-ssj Kp. m y be

m ' I t t e n in t e n l of the Oibbs f ree energy as

= - - - -

R'I"

(The 8 u p o n s ~ p t 0 ind ica tes t h a t the f ree onor~o8 are evaluated a t the

8~endard s t a t e of one atmosphere.) ~n t o m s of the pea ' t i t ion func t ions j

the equi l ibr ium constant f o r the d~ssoolat ion of a d t a t ~ L o gas nay be

written

or~ oonb~:Lng the idea l gas law and the p a r t i t i o n funct ions

This equat ion lwprosont8 the oqutl4brium COherent on~y i f the

o loo t ron io oontz~bution8 to the enor~7 are n o g l £ ~ b l e . Houoverw due

to t ~ high t o ~ o m t u r . ! required fo r 81gni f teant d iesoc ia t ionp th io

assumption t8 ques t ionable , Haneon (Reference 28) ha8 ca lcu la ted the

equllibrCum constant fo r oxygen including two e l e c t r o n i c 1cycle past

Page 23: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

the ground s t a t e fo r the aoleeule and four e l s e t r e n i e l eve l s pas t the

ground s t a t e f o r the atom. Ranson's r e s u l t s a ~ eo~oar~ to thJ v e l m a

predieted by the above equat ion in F i g , s 2-J . The omnparimon IB not

too good. Fur ther cons idera t ion and an ana lys i s of t ~ e£fee~ of h l lbe~

elsotz.x~Le states x~veals tha t the elee~.~nAe statas fo r the i tem lllNJ

nueh nOl~ s i g a i f i e a r ~ than the e lee~ronie s t a t e s fo r the noleeulo . This

fol'tUnete oharaete l~ l t io 8 1 1 N & ~oh bet to r 8 p ~ t i o n t~ tbe

e q u L t i b r l - - eon~tant to be rode by negleot~ng the Ttb~at ie=al t e ~ f ~

the aoleeules to offset the eleetronle tarasp He Figure 2-), 1~erefore

the equillbrlm constant nay be eonsldered to be

I 131~~ ~.(r ~ T317" e,/,~ ~. ?-~k Lz-1)

Yn th i s studyp t h i s r ep resen ta t ion of the e q u i l i b r i m oonotant has been

corrected slightly b~ eva1~ating the ooe~flelent to give the e~ N-

se~t at a teaperature near the msxia~ temperature eoneldetwd. Lisht-

hill's "ideal dlssoelating gas" uses a similar approxiaatlon for the

equ l lAbr im cons tan t . Equation (2-7) incorpora tes add i t i ce~ l ~lgor~

s ines i t ino~udee an a d d i t i o n a l square root of teapera ture oorlwetion.

~. Recombination Rate

The recombination of atoms to form diatomie molecules i s genera l l7

considered • termoleeular r eac t ion in whleh three i~dlv~dual pas~tele8

participate in a single kinetic presses, the third particle being neces-

sary to remove the energy of recombination. Humorous theor ies have been

advanned to predic t the valse of the recombination rate f o r t h i s type of

roaction~ and References 8~ 29j and 30 contain discussions of sores of

Page 24: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

!

p

I

I0

5

- I0

-15

- 2 0 0 2 3 4 5 6 7 8 g

TEMPERATURE °K x 10 -3

FIGURE 2 - 5 EQUILIBRIUM CONSTANT FOR 0 z ~ 20

Page 25: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

-16-

theN theories. Unfos~una~elyw the various appz~aehss do not sjmej

pe~oular17 :eprdlng the tenperat~re dependeneo, Xa photo1 it n8~

be eoaeXuded ~hat the ae~Iva~Lon e ~ required for the meoublnatlon

pl'oeoo8 58 ne~Lt~bla and the =ommbtnation r a t e b u an s l lpbra£e teD-

p e m t m d o p e ~ o

The laok of aKreemon~ ~ o u ~htm po~n~ on i8 evident upon ezaninat ion of

Tablm 2-1 (abetmetod f~on Re£o~eneo 29). Thl8 ~ b l e 1JJr~e ~ho values

the reoombtnat~on r a t e ~or o ~ n ~ t l ~ oct ~oFth In the l l~e~s-

~ ' o . Szpes~umn~ dal~ £or ~ and other high tmupemtm ]~oaotJono

8poAse and quootionable~ oinoo in p n e ~ d ~ dlooooiat4on 1',8~ ~LO

noeou~od and the equt lSbrLm eonetan~ then used to oa leu laM the s, eomt-

bSna~lou m~o. The ~ ae t4va t ton enors~ r o q u l z ~ ~o~ dtseoeta~don 18

~uo~uded in an e z p o n s n t / ~ Vm~p~atus~ dopon~nw ~ h e t t n ~ l ~ s ~ msslm

the e~o t value of n in Squat/nn (2-8), Yni8 study Is of the street of

various z~Inat~on rotes and the ~ens of BqustJ~a (~-8) Is eatlsfae-

O. Reeotlm Beuatloa

Diuoeta t ton of a dlstomle nolooule I F be oouides.od to be t ~

: ~ m l t of a oo111alon betueen a mo~ou~ and another pa~ io le Lf 8uf£1-

etmst e n o r u t o avai lable to break t ~ noleeula: bond. 8 1 m l l ~ y :

~wo atom in the j=eNneo ot • ~ par~lele. The oppooiag reee~tmso

of d548eela~J~a and reeoublns~ou my be n p ~ d ag

Page 26: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

b a a s b / n a t ~ o n Rato

m, 6 llS.mols "?. mo ").

q ' 7

z.6 s ~o'- Joo

h.05 z ),0 ).7 ~ 5 ")"~

h.SJ z :w 17 ]~5 ,.o.~

3 z ).o~ ~ 5 o.~

~ . 2 , ~o~+ .~ '~.~

?ab),,e 2-1 Reoombinat, f,on l~to for Ctz~l~S

-17-

Page 27: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

.18-

ko

k D - d/ssoa~s~ton rata

i~ - reoonbinst~Lon mrs

The d t H o c t a t l o n m~e J4 4ot2ned ss

(t'be rote ot pzmSuat~on of dtuoc~Latod 8]?oo1441 t.II propol~lon81 to t~o

o ~ o o n t n t L o n of tho d l a t ~ t ~ spe~Los tJ.uos tho tot83, oonoontmtton ot

the n t z t m , ) :he rooonbtnstton ro te JLs de~Lned M

The net ~sn4e of tho a tmde spooLee £s themto=m the sun of ~hoia two

ozpl~lJn/on4, Bzpandlns ~ho Euler tsn doWLvstl~o and l~Otz~Lotln8 i t to

stosdT' Ft.ovp t h i s sun beoouoo

A pe.-t lmLla: ease t o t uhtoh t h e e te no not rata ot preduotlon

o~ o£thoz, ohemlosZ opo~Lo8 Is • ohelLosl equ£Ltbr£uu sta te , to&" oqull:L-

tn~Lm the 8bovo equst~Lon I~eduoos to

or~ 2n ~onm of p s r t l a l pmNures

Page 28: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

Irmpactton shoe8 t h a t t h i s r a t i o of p a r t i a l proeSUlW8 t8 equ iva len t to

the equi l ibr ium constant fo r the reaot ion being oongidegwd. Therefore

P.T

Although the above equation has been derived fo r the p a r t i c u l a r ease

of a system in equi l ibr ium (and thus no change in oomposition)j i t wLU

be usod fo r t h i s problem since i t i s gene ra l ly agreed t h a t ~ j ~ p and

Kp are a l l only func t ions o£ temperature and not composition and tho

r e l a t i o n s h i p w i l l hold fo r a l l eases in uhieh a mixture tompoFatum mn

be def inod. Feldumn (Referenvo 31) s t a t e s t h a t t h i s r a t i o may be uood

in non equillbri,u eases ~en the Individual partlele8 haw an equilA-

bri~ statistical distributlon of their enerBy levels. ~ therofe~w

redueeo to the ass~ption that the relaxation time for tbo varlouo

energy modes is very ohort e o ~ to the relaza~len tlao required ~e

attain ehemieal equillbrlem.

The opeciee eontinulty equatlen, or reaetlen equatlen, for the

nozzle flow problem nay now be wr i t t en am

]~. S . m a n of Won D S a o . o ~ l m d ~ i . * t ~

A oct of equationo d u o r i b 2 ~ the flow of • s ~ m t ~ diato~Lo

gao have been dmmloped, To tae i l t te te oubmqmmt ooNmt~ttonop the

-19-

Page 29: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

-20-

a r e a . dls tar~ep velooLty, t e e q ~ t u r e e dens i ty , rand pressure otn be non

d:L~ons4onal.£~d w~Lth respoot to e ~ refere~oo aond£~ioas. £ndleated by

the subea~Lpt O. The ~ u l b L n g equat ions are

¢ont~nu$~y ~uat£on

Mce~snt a Equat£on

(,z-~i)

P.,To tt-lz)

V~ = - - l + O ( o

E n e ~ Ilust~Lon

,V cl,~ .+~k,. c i l~t , l , 10c~I" +DK ~. O(~L-Ix~:)l=° t I'-14)

P.,To

0 = ~'---~ (t-i,.) V,To

. ] I , T ~ -- e,L) -l tz-*~)

Page 30: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

-21-

Equation of S~a~

Reaction l t u a t t o I

(,t-~e,)

I?.. DAI~ 4 y." r'. k,L ¢- T.'- -~".

( z -~

(,7.-I.o}

C, (,T '~ : 4~. T tl-z,)

Page 31: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

III. SOINTIOm8 A~D DISCUSSION OF RESULTS

Ao General, Co, nstdel 'at ioM

~ s reforenos condi t ions ~_th which the dimensionless va r i ab l e s

sre formed are aos t con~snient17 chosen to be those s t the nosslo t h r o a t .

Examination of the con t inu i ty equation shows tha t t h i s oorruponde to the

poin t a t Mhlch

For a wartety of pa r t i cu la r eases th is equation proTtdes an e z p l t o t t

d e f i n i t i o n f o r the v s l m of ~ (which i s a funot lon of the o r t t i e a l

w l o o i t y a t the nossle t h r o a t ) , Hom~mrB in general t h i s oondi t ton

be r e l a t e d to the nozzle geometry through the r~aot ion equat ion and the

reocmblnatlon r a t e funot lon . Phys les l l~ . ~ uan he considered to be an

effeot£Te ra t i o ot speoJ~ie hsatos since i t performs a fonet~on s t a i l a r

to that r s t l o i n c lass ica l sas dynaelos.

AnslysJJ of the equat ions l i s t e d in the prsoeding sec t ion shows

tha t both the con t inu i t7 equation and the energy equation may be i n t o -

grated d l rec t l~ with t lw resul ts

-22-

Page 32: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

=~-

1 (s-z)

Stnce the equat ion of s t a t e to an a l p b r a l c equatton and ean be solved

exp]£ottlT~ the problem tha t rematrm t8 the I n t e g r a t i o n of the momsn~m

equat ion and the reac t ion equat ion, A ca re fu l study of the r eac t ion

equat ion Indica te8 t ha t i t ~oald be extremely d i f f i c u l t to I n t e r . a t e

a r~ l . r t l ea l ly~ ovon fo r w r y o:tnplo e s N s . Homver~ oneo tho mmalnder

of ~he problem has been solvedj the motion equation nay be e n Z u t e d

e i t he r n ~ r ~ e a l ~ y or gmphtmLt]~r~ to obtain the nossle con to~ . I t

can be pa~la~Z~ lntegrst~d to

17" c cx

Zna l~ t t ea l so lu t ions to tlw mmntnm equat ion IS7 be obtained f o r s few

eases j bu~ In ~ z m l n ~ s r l e a l techniques mint be employed,

1, l~osen Flew

I f the roooubSns~tou rat~ i s olov enough oo ths t tho eoupoot~ton

of tho f l og doe8 no~ a h a n p appreotablF during tho noszlo expan81onp

the f l o g 4s 8o£d ~o be f rosen. ' l 'b~ ~ be considered to be the ease

for .hteh Dsnkohlsr,s f ~ s t ooef f io tont i s

8Saw t~ to ~ f ~ d ~ a ehsz~oter ls t lo t i ns f o r z~s~ ion divided by

Page 33: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

th~ ~ss£dsnee t ~ In ths no~sle.

~ossls th roa t 'must be ouoh t h a t

In t~hts OaN the oondttlons s t the

F/~Lre 3-1 ~ w o th is ~eoult Smphleall~ fo r ths l n l ~ a l eond i t iou

dose~Lbe4 In appsn41z Co

The p u s q ~ equatAon f o r flow 'mloo£1~', Equation (~-.2) m y b~

s p s o l a l i s ~ to the a u g of J~ossn flow.

The Aonsntua equat£on oan be IntI1~ated f o r t h l s o a ~ by oolbln/n8 i t

e i t h ~ n l o o £ ~ - and the equat ion of s t a t e . The ~ u l t

• Y T . I } L .,J ' - '

2, I so the rna l Floe

An ~Lmothorm81 f log oan be mLtn~etnod EhroulJhout the noMlo empma-

8:Lon 4f ouff£etmn~ ono~lF 48 lwloaimd by tho lWoombinat~ton of atoms, In

t h ~ c a n ths oondit lon8 a t the nossle t h roa t must be suoh t ha t

L

This oondi t ion 18 f lmphioal lx swprosontod on Flfluro Jo l .

8pocialtmtnil tho v e l o o l t y to the cane of an i8otholwal flovp tho

mault~ is

Page 34: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

1.80

1.70

1.60

1.50

1.40

1 . 3 0 j

1.20 - ~

1.10 •

I i

1.00 L, 0

J FROZEN

J J

EQUILIBRIUM /

J ISOTHERMAL FLOW

0 . 2 0 0 .40 0 . 6 0 0¢' o

0 .80 1.00

FIGURE 3-1 THROAT CONDITIONS

Page 35: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

-26-

~ - l'~ k~- , ~ ,

Again tho momentum oquatton nay be in to~ .a tod i f t h i s oquation ~ eombinod

With the equation of o~ato and the p~eoouro may bo oxplweood ao

L ~-~)

3, g q u t l i b r i m Flou

I f tho reac t ion t~no i s very ebort ocmparod to the nu tdenoo timos

OF

DQvv~ / - ~ I,

tho f l o w i n oaid to be an oquil~Lbz'lum flow and the oempoottion ~ •

untquo fumetion of the oqut~br tum eonstmant and the p~onuzw° For

equ i l tb~um flow tbo t h roa t condi t ions nmot 13o ouoh ~hat

t I 1

Page 36: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

-27-

The z~aJt~.io~io~ of oqufJ~b~Lum :r~ov does not pz~luoo • ar£Kn~l~ioont slnp14-

££oat/~m fo r the momentum equat /~nj and i t s ~ Z sonnet ha i n t e g r a t e d .

l m r o w oh~1.~8 and tab].os £o1. equ43.ibr£tm plmpert ios have boon pubiS.shed.

4 .O. j ~ o r e o , N 3s to f & O i ~ J . ~ nunorioa~ m~oula t ions .

h. Zsobe~o-~ovo~ F3.ov

k~thoush perhaps not too £ n t o r o s t ~ g ~n a p h ~ l e a ~ N n N ~ an

ans]~p~i0a~ So~utAou m y be obto~nod for the o8o0 of oonstant p15ssu~o

f lm, ' . App3.ioation of the exaLter/on for the noss].e t h ~ a t 7"dLm].de

L

TJmpeotlon of t h i s o q u t l o n show t h a t the oondl t ion for a t h roa t ro -

qu/~es an oxo~hozxLo d ~ s o e 4 a t i o n r e • o r l o n . :Lf such a g u usro u o d .

• unique t lwoat tonpemturo would be roqu~-od s • s p o o ~ o d by the above

equat ion . A o o n v o r p n t - d l v o r p n t noss l s £s /mposslblo for the gaNs

eons£dorod :in Appond/x C; hoverers pure ly o o n v s r p n t or d l v o r p n t m o -

t i o n s nay px~duoo ~ n s t s n t pressure f ~ o l .

Throujh the momentum equat ion i t ~ n he Non ~hat • cons tant

p l ~ S S m n o v n u t oorrospond to a oongtant voloe£t~ ~ o v and the men•n-

tun oquat~Lou s, eduoos to • t .~v~a l Idon t l t~ .

5. C o n s e n t Densi ty

For son• ten t dens l t~ f lov the ~mdl t l ons a t the nosr~e nust be

suoh tha t e i t h e r

Page 37: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

-28-

~7o ~ O

01"

~ o

The t ~ s t rost4~Lot4on o o m s p o n d e to the oZus ieaZ ~ of an h ~ o n p ~ o s -

sLblo t l o v wLth no t e a • f l o e . The a l t e r n a t e ros t r4o t~on roquLros t h a t t h e

t h r o a t ooeposLtlon be an ~ q u 4 1 i b r 4 s oompos&t&on. In nsLtber aam ~Lo a

un~quo throat ~loo~t¥ dat~nod.

6. Disouss:Lon

Sons r a t h e r Lntoz~stSJ~ r e s u l t s •an be doduood f r e e a oa r • f e l

s tudy of Fig~wo 3-1. ~ r e p r e s e n t s an e f f e o t i v o r a t i o o f s p e e t f i e

hea t s i n de f tn tn~ the o r l t i e e l v e l o o i t ¥ of 8 r oao t i ng gas n o w a t t~o

t h r o a t of 8 n o s s l e . For the e~ase loa l u s e i t va~_os f ~ n 7/~ f o r •

d~atomle gas to ~/~3 f o r • monet•rile i~m. Hoverer . t h i s f and~ i~ , zsw~o

i s t nozao t , s lneo the v i b r a t i o n a l enorgF has no t been tnoludod. F igure

) -2 shows t h a t the *neZus4on of the v l b m t ~ n a Z t o m 1torero the o f f e c -

t£ve spee~f.e hea t mt~Lo t~ appz~xlnato~y 8 per oen t . S~noo thLs 48

the ra t40 of two t enpe ra tu ro dependent funot£0n8 and vs~Los Zmss than

e l t b e r of them • l o n e . I t oou:Ld be e n t r e / p a r e d t h a t t h e l ~ uould be •

oonaidel~blo oox~root:Lon i n the oalouZLat:Lon of t~o o tbe r f l o v p a n n s t o 1 5

the ~ . twat~onal enoray ~s n o i S e • t e d . The r o d n s n ~ g f e a t u r e £s t h a t a

voz7 high pro•sure vould be roqu i l~d to oxao t l7 appl~aoh t h i 8

• u s a t the f~md t enpors tu ro of h050 K f o r vh~Leh the eul~ee are dravn.

Page 38: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

7.00

IN ;>

6.00

5.OO

4.00

3.00

2.OO

1.00

FROZEN FLOW

=o = 0.50

T o " 4 0 5 0 K

J

INCLUDING VIBRATIONAL

/

1.0 0.80

j ~ - - ~ N E G L E C T I Nt.~ v,~,~o~ ~

0.40 0.20 O

f

0.60

TEMPERATURE

FIGURE 3-2

EFFECT OF ON

VIBRATIONAL VELOCITY

ENERGY

29 -

Page 39: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

-30-

Howovorm t~o tno lus ion of the v i b r a t i o n a l o n s r g oontinuos to haws an

o f f s e t , of deoma~ng n a ~ t t u d e t as the e o ~ o s i t i o n ohanps to the o ther

luct~ms of a pure monatomlo ~ (oozTespondint to a wsry low pressure) .

~ezqforep exespt fo r almost oompletoly dlssoe~atod f l o w p the v lb r a -

t l o n a l tense should be oonsldeFed. Figure ~-2 shows ~hat t h ~ s t a r esn

exceed ) pea" cent i n the ws loo i ty fo~ O( • " 0,50. Of oomees the e r ro r

wAXl be greater f o r smaller values of K .

The ~ fo r squ~ibr ium flow nate~os t ha t f o r t roson flow a t the

end points ( the 14-4ring oases of the sere and i n f i n i t e pressure) and

drops shup~y in the Intermsdlato n n p , apps'omohtng the mum of I so the r -

z a l flow. This follows f r o s the f e e t t ha t in t h i s region the oomposltion

is psrtieularl~ mnsltiws to pressure . The value of ~, f o r the i s o t h e r -

mal flow of a roas t ing gas i s independent of oompositlon and s lues to

un i ty . In the l i n l t i n ~ u s e of an infinite dissoedat ion euergy, i t i s

sXaot~y un i ty and the flow behaves S ~ L T ~ T to the o l a s s i e a l lootheraal

flow, studied by Rotor and Ca:he1 and reported in Referenes 32, Sines

no ohan~ i n oosposi t ion would be required to mLintain the t e m t o ~ .

The th roa t wslooit~V then oos~uponds to Newton's isothermal speed of

sound.

When o ~ t d o r t ~ the flow of a r eae t i ng gas. i t i s r o l l to z~mm-

her t h a t the oomposition must be appswaohing equillbs~um. The dev ia t ion

from equil£br~um might "inorease throughout the expansion presses , but

t h i s must r e s u l t from the equi l ibr ium po in t shaming sore r ap id ly than

the flow can fo l low. Considering t h i s , I s o t h e n a l flow csn e x i s t only

4~ ~ ) OCe . s ines t h i s w i l l necessar i~y r e s u l t i n recombination.

Page 40: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

the r a t e bolnm cont ro l lod b~ tho mcombinatlon ro te funotlon~ F.

c. c o w e r So ut o

I . Nouslo C ~ t o u r

The Ina lus lon of the spoclos aon t lnu l ty equation urlth tho convon-

t i o n a l p s dT~malo o o n s o m t ~ oquatlon8 has addod two addl t lcmal wmrl-

ablesw the ccapositlon and the nossls geometry, Therefore an addit ional

squat ion d o s ~ the nosu~o contour i s l~qutz~l to ob ta in so lu t i ons .

The ~ purpoN of t h i s study i s to azamlns the o f f s e t of the rooom-

binat~on r a t e and thus the c~otw of nossle contour i s a r b i t r a r y . The

n u t eonventont contour

has been ohoNn sad 1o s h o ~ tn Ft~we ) - J , ?h i s p a r t t e u l s r shape has

s s w r a l n o t u o r ~ h y ohsrsoter is t lOSo P r t a s r t l ~ t t s t a p l t t i e 8 the equa-

t i o n s and decreases the ~ o ~ e x l t l e s of the coaputer progrsa, In addi-

t i o n i t i s f ln4d moohenloally £oasiblo s ines the naximm valuo of the

ha l f angle In the oxpansion i s app rox~u to ly 15 d o u s e s . In addt t lonp

i t fo rces the raaot40n equat ion to p rod i s t a soro dsx~Iv&tlvo fo r the

composlt~on a t the throatp u o a t l ~ slmp34~Ing tho s o t t l n g of the i ~ t t l a l

eondlt40ns (me Appondlx C). The naJor d l s a d v s n t a p of tb£s nossle i s

t ha t i t does not aetua1~y haw a t h r o a t , or a tn taua po ln t , but slneo the

teuporaturo nust decroaeo as s roeu l t of the eomputer pz~grem, t h i s

d i f f i c u l t y Is m/nor.

2. Campu~r ~qL~tions

Considorablo care ~ be ~.von to the fora~Tatton of the equations

Page 41: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

I

!

FIGURE 3-3 NOZZLE CONTOUR

Page 42: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

-)3-

and s o a l f ~ of the ~rtables before t lwy oan be proMmmmd for s o l u t i o n

on an analog eomputer ( d e t a i l s are presented in Appendix D). I~ w i l l

s u t f i m to n o ~ tha t s ~ m s

T - I - lOOv

p " I - lOOt

t T - l - l O O v

- l - l O O t

and the maoh/ns tdLms I s s l o m d down by a £sotor of ~0, £@tsr c o n s i d e r -

ab l s mn/palatlcmm tho c c ~ u t s r equat lons mn be wr i t t en as (M i s the

~ l ~ o e ~ b ot the area)

dT - - I T ~ - d--t I o o o [~-~s~

a t ~o

m

d~. = ~ [ 1 T 2 . =j T TM .

- ~ L ko, ooo * 1>°°°°°° 0< - ZOe d/ dt

• ~eo,, . --j- E . g - e . ] ~.g,. ~o-ooT 2i '

- g D

Page 43: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

- - - ~ ~ T - s o , o o o - ~ o o ~o T D o o ~ < ~ a t

dN _ t I I .~ I d__~ x a--~ 1oo M ~ T ~ - 5o, ooo Tboo.~) at

I d~ • t d~< I (S-Ls) S o ~/~ d~. - ~ o o ~ , t ° ° ~ < ~ d -q

- I d G , t CaT" ÷ - - D G {.3-Zo) d t 1 . o o o ~o

_ Sor~ 1 {,s.~.L )

A eoBplets d l s o u u l o n o£ b o ~ d ~ 7 oondl t lons i s ~Lven i n ~ n d J 1

C. Three main eases N r e s tud ied ~Ipendlng upon the I n i t l a l O0~pOl~ti~}Dj

equ4"Jibrium, above equllibr4.um~ and below equilib~Lma. For saoh o f

t hese main oases , seven o u b c a N s o f d i f f e r e n t t e s ~ r a t u a w dependen~ o f

Page 44: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

tbe roocubtnatLon fune~ion are ~ . The simetrun of reeoubins t icu

funo~tons sra shmm in Figure ~3-~.

J . RosulW and I)iscussion

~yp~oal so lu t ions from the analog o ~ p u t a r ara sboun in FJLsuras

~3-5s 3-6j and 307, The t l o g v s r a ~ l e s behave 8s oxpeetod and tbe

p r o s s u r a - t e a p e r s t ~ curve i s s l i g h t l y bemd as a r e s u l t of the tno lus ion

of the v i b r a t i o n a l s n o r g as ueLt as the rasomb~at4oa r ean t i on . Tho

value of V 2 (sssentta].l,y the Ho 2 of oZimalelLl gas d~q3amiol) 1"~e8 rap id ly

and thou a p ~ e h o s an asTnptotio ve~Lue ( fo r f rosen f log t h i s must Zie

between L.o (mnJtcato ms) and 6.2 ; (d tonio Sas)).

The oheuloaZ offootaJ in the f l og stream are more in terost tng then

the f l u i d moehantoal v a r i a b l e s . Figures J-Sw ~3-9p and ~-10 show the

chanso in e h e ~ e a l composition as s funot lcu of temperature. Prov~us

4'mvost4gatere, ioO., Roforonose 19 or 20j have Lud4eatod t h a t a t the

l e e pressures s~udiod h e n the anoun~ of ches~oal rosot ion ooeurr ing

dounstl~an of tbe nosr£o th roa t should bo neg l ig ib le . Thus the so lu t ion

ns~ be adoquatel~F rapresentod ~ the f roson f l o g soZution, This eonclu-

8ion i s subs tan t ia ted fl~U th4s study fo r those cases u i th the recombina-

t i o n ro te an inoreasing funo~4on of temperature (n > 0). For these eases

tho rooombination r&te funot iou beeches 8mall quiokly , end thus the

ohesLLoa~ roso t ion d i a l out rap4d~y3 beforo a s ignLf ioant ahsngo i n oom-

positAon can ooour. The o f f s e t of the d4ssocia t ion ensr f~ i s g r s s t l~

d i lu t ed 4f thora ~Ls onl~ a nual l composition chango over a largo tempera-

tram drop, Sinoo the moloeular weight corroc t ion i s a (1 ÷ K ) term.

small ohar3~os in composition ~LZ1 hays nogl tg tb le e f f e c t s on the

Page 45: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0

2.0

J

0 . 5 , ~,,~

0 . I

1.0 0.9 0,8 0.7

n=+ l

n-+:

0.6 0.5 0.4 TEMPERATURE

RECOMBINATION RATE FUNCTION

FIGURE :5-4

- 3 6 -

Page 46: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0 I

To = 4 0 5 0 K

Po = 2 arm,

(xo = 0.50

n - ' - 2

2.0 f

0.5

0.2

I

0 . 1

1.0 0.5 "0.2 0.1

PRESSURE

|

0.05

NOZZLE

FIGURE 3 - 5

FLOW PARAMETERS, CASE ID

- 3 ? -

Page 47: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0

T o= 4 0 5 0 K

po = 2 otto.

=o = 0 .667 n = - 2

2 .0 .

1.0-

0.5

0.2

O.I I

1.0 0.5 0.2 0.1 0 .05

PRESSURE

NOZZLE

FIGURE 3 -6

FLOW PARAMETERS, CASE TrD

3 8 -

Page 48: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0 I

T O = 4 0 5 0 K

Po = 2 o t t o .

(Xo= 0.333

2 0 , . = - 2 ! ~ S I

I.O =

I

! | 0.5

0.2

0 . I " i I

1.O 0.5 0.2 | I

0.1 0 . 0 5

PRESSURE

NOZZLE

FIGURE 3-7

FLOW P A R A M E T E R S , CASE TIT D

- : ] 9 -

Page 49: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

I 0

0 . 0 3 0

To = 4050 K ! n = - 3 f n = - 2 I Po = 2 o t m

0.025 ~ °¢o= 0.50 I

0.020' I =-I

0.015" ~ n

0 0 0

0 . 0 0 5 " ~

- 0 , 0 0 5 . . . . . . . . . . . . .

-0.010 1.0

I

0.9 0.8 0.7 0.6

TEMPERATURE 0 5

FIGURE : 5 - 8 F L O W C O M P O S I T I O N , C A S E I

- 40 -

Page 50: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

tS I

o

0.030

0.025

0 .020

0.015

0.010

0.005

0

I

T o = 4 0 5 0 K n = - 3

Po - 2 otto I ~o = 0 . 6 6 7

- 0 . 0 0 5

-0.010 1.0 0.9 0.8 0.7

TEMPERATURE 0..6 0.5

FIGURE 3 - 9 FLOW COMPOSITION, CASE l"r

Page 51: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

I o

0.030

0.025

0.020

0.015

0.010

0.005

0

-0 .005

I To =4050 K Po = 2 otto. O¢o= 0.333

n=+3

n i-l-2

/ J n = + l

-0.010 1.0 0.9 0.8 0.7

TEMPERATURE 0.6 0.5

FIGURE 3 - I 0 FLOW COMPOSITION, CASE TIT

- 4 2 -

Page 52: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

no),ooulm, tmisbt.

Susqn~ in i i ~ dollherato)~r •tdu~ing • t the t~-oat v*~b • non

oquL1J.br*m oompoad.~on ham on~ • 8m,1.1~ thoulh prmotmoodp eff•o~ on

tim oompooL~on protL~o•, In par~ th~s L• • rooul t o£ the oh•too s t t~o

noss~o oon~ull's 04~ooj i n ~him osN; t~o ooupog4tion must • t4r~ a t tho

5d~o&t ~ h • so t s r a t e o t ~ in 8 ~ c u s s , Thus the nosslo t h r o s t

n~y be oonsidorsd to be s t • s~ato s t pseudo t rosen ••rip•stOLon,

~ S s t i v s exponents (n < O) far the r e o o u b ~ t t o n rt~e produoe s

d i r t • m i n t o3~ss of so lu te•us f o r ths t~ow eaepositS~n, Inspect ion s t

the mo~Lon oquat~on ~ provide •sue inlrlSht Into th is dlot ino~ion,

Thoro ann bea4oa)J~ ~vo ~orno in t~o roaoLS~n equat4ou~ one Lndtoatin8

t~o dLtuot~on and O n t to vt~oh the f )~v d s v ~ e s ~rou oqullXbr~um

and the o~her~ o o n k d ~ J ~ the roocubS~tt~on rat4 funsa l •n• i n d L u t i n 8

the speed v*th Vhloh the t o s s , I o n v~3~ •sour , For t~o •ass of n ) 0 the

m r 4 s t s~sot lon te rn sona r • l • the oh•r ip in ocapos4tlonD and s , no• £t

oonst4nt j o r noar~y oonst4nt j vs~ue qu*ok)~, For • n q s t l v o ~sluo of n

the ra te s t r u o t £ o n t4rn S~n~ums v~th d e o r o u i n ~ t~npersturo s the •

bsv~n~ • t4ndenc~ to i n o n u o ~he rt~o of ohenp of • • r ip s • i r i sh ,

5~e to rn i n d £ o s t ~ e~on~ of the dov~st£on i ron oqulltbr~um in

the roao~£on equat ion ~s ~n ~onoml • deos~asin~ funot4on v*th do•ross-

t a p o m t u m (although 4~4t~a~)~r 1re value ne~ increase dependtnir on

b L n l t i a l aondit~Lone)= and at ]Low t4~oratores the cl~mp in ooapoe:L-

t~Lon nust spprosoh sero. Houe~er~ fo r the 1or pressures and prossure

rs t los oonsidorod here~ the •topers•ore does not dec=ease s~ffLoLently

Page 53: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

f o r ~hls seeondary e t tee~ to l m , i c u t ~ U . Untor~uns~e~y, the eeupu~sr

everloaded f o r tnpemtu~8 ot about 0.60 t o t n s j s ~ t w n ' s , end seas

minor mseaLtag of the problem l u l d be neeosss ty ~o obt~b~ soZu~Aou f o r

grea~er ~aupersture r a t i o s .

The eholee of nosals eon~our 18 of p e ~ i e u l a r s lgn i t i eanee In

de~eraia iag the oeuposit t~n. The LS~ear nossle s~udied here res~r ie~s

~be slope ot the eonposit~on p ro f i l e to sero a t the ~h l~ t t . This

e f t e c ~ v e ~ y smooths out ~ s o o u p o s ~ o u ebsnSe end d e a r e u e s ~he e t t o e t

ot r o o o n b ~ t i o n m~o on ~ o t l o u vs~Lsb~os, I t ~Ls sn~io~pe~md t h a t

othor nossl.os wou~l.d gl.vo oomtido~b~,y dU'fmNml oonpool.ll.on pl'oflloJj

par~lou3arly t o r ~bs eeses in uhieh the eoupostt lon Is not Inlllal.l~y In

oqu4Zt~-~m. Howver~ ~ o oonelus~ons of t h l s sSmdF shouZd not be

at toe~od.

Figures ~-~A~ 3 - ~ j and ~-1~ eoupare ~he veloet~y~ prossure~ and

a r e s fo r the two szWeme ease~ of reoombina~lon ra~e considered. As

~ould be oxpoe~odj the wZoe4~, ~nomasos note mptdl,y in tho ooUFold-

tJ~n ehan~ss as s resu l t of ~ho dt4soetst ton energy being re~urnod to

~he tlou. This sans effee~ aeeoun~s f o r the tact ~hat~ f o r a given

~npem~uze m~io, ~he area i s considerably dLfteren~ f o r the two e x -

t~eus eases. The resu l t ot th i s area lnerosse also causes ~he pressure

~o drop more mp4d3~y f o r ~he case ui~h groa~er reaction (with respoo~

~o taupera~uro), Xn terns ot a given nosslo wi th a t tsnd area rat to~ i t

can be seen ~hat the exi~ pressure is approstnatalF the sane and t~o

ve loc i t y i s grea~er by spprozbuttol¥ 5 per eent f o r the can of neg l ig ib le

reae~lon. Houever~ ~here i s 20 per eent more t h e n s 1 energy rens in ing

Page 54: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

4.0

:5.5

3.0

2 . 5

> 2.0

1.5

1.0

0.5

0

J

1.0

T o = 4 0 5 0 K

Po = 2 otm. (xo= 0.50

0.9

/ /

J n - - 5 ~

0 . 8 0 . 7

TEMPERATURE

r

0.6 0.5

J

FIGURE 5-11 FLOW VELOCITY

- k5 -

Page 55: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

1.6

1.4

1.2

=- 0.8

I

To = 4050 Po = 2 otm.

(Xo= 0.50

K

0.6

0.4

0.2

0 1.0 0.9 0 . 8 0 .7 0 . 6 0 . 5

TEMPERATURE

FIGURE :5-12 FLOW PRESSURE

- 46 -

Page 56: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

1 .8 ~

1.7

1.6

1.5

1,4

1.3

1.2

I.I

1 To = 4050 K Po = 2 o t m .

_ ¢x o 0.50 , , I

n = - 3 i

I

' ~ ~ -

1.0 1.0 0.9 0.8 0.7 0.6

TEMPERATURE 0.5

F I G U R E 3 - 1 3 FLOW AREA

- 4 7 -

Page 57: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

the case of t~s t a ro sot&re mg~uro ~ o h ooQld po~sn~gAlly be ~mns-

la~od in to ~ns~Lc o u r w , In ~orms of mob nw~ors tb&s dg~foronoo

flow ~ l o o i t y would be oonsidorably ~ r o pronolnoods stnoo i~ would 9~-

oludo the ~omporaturo s l s o ,

of the e o l u t g ~ ob~tnod in th&8 s~udy ~ h ~ho ~oop~lon

of thoee l~'eeon~d in thg.s 8ootgLon~ 8ro 9J~Og.udod in Appendix IB~ Romultdn.

Page 58: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

The oonolwions of th is t m a t t g s t i o u s ly be ausmsrJaed as folloess

1, The sm~log ooapQter has been proven to be a versat i le tool

f o r em~Lning the tlow of a r e a ~ i n g gas. ~ m~or ohanps

An tim prograu umd in ~his stud~ uould be nocossary to

mmmt~ the oomplolm e p e ~ of poss ib le boundary oondlttone,

2, Coffee,Ions to L t s h t h ~ e e widoal d t u o o t a t l ~ gas: are

readt~ disoernabla bu~ not of major t m p o r b ~ ,

The ez~nt of reaction and shape of t~e cmposttion pro f l la

i s pr taar i l7 detomtned by the fora of the reaction rata

law,

~ o t l o u r a t e s t ha t i n e n a m with temperaturo ha~s l i t t l o

o f foo t on the flow eo~os t t~on Cat low pressure) and 8uoh

flows say be a u m e d to be f rosen ,

Roso t~n rat~s ~hat d o o m u~th ~Mporaturo affoe~ ~h8

e o ~ o ~ t ~ n s i g n i f l ~ n t l y and in those oaso8 tbo ohomioal

roao t ion nus~ be eor~f, dorod.

Z n t t t a l l y non oquilibr~Lum eonpos~t~ns r e s u l t In a g rea te r

or lossm" ohanp An couposttion~ bat ~hls effoo~ t s coupled

w r y e loss l~ to tho par~ ieu la r noszle contour considered,

The ef teo~ of t o m of ~hs mccubina t lon ra te on the ~ l w of

a ~'eaotlng gas t8 s~gn~f i~n t and mugt be d o t o ~ d e~aet~y

before d o ~ a ~ d m u ~ m s of p o t e n t i a l appl£eatton8 can be made,

.

.

.

.

- L g -

Page 59: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

V, JlK~JO~DATD~I~ YO~ FUTURE INVESTIOaTOR.5

The t u ~ L ~ y u ~ h uhioh the N~ o t 0qus~0nS dosoribin¢ the f!ow

o t s r o s e ~ 8as s u a o s ~ s ns~y sddi tJ~m~ s ~ s of ~ s ~ l o n .

1. The ncss lo oon~our has • detin£~e e t t o ~ on the o ~ p o s l t ~

protL~e 8nd a var4_oty of oon~ours shon3d bo oons~a r sd , Un-

loss considorab3~y t a ro ocupu~n8 oqui~nsnt ~ m s used in

th4t s~udF Is m S ~ b l o p ~ would neoossl~a~e using tho

cons~dersb~y s ~ 3 ~ d mdoZ of a d i s s o ~ s ~ Sss suuos~od

by

20 Tho e ~ b e ~ of bho e~mlF of • d~aoo~t4d gem ~ t,o the

e~ud¥ ot o t t he r • p u r e ~ lon:tsod f lng or oven a psa~tal~y

d~ssoo~a~! and p s r ~ 5 ~ y 4on~od ~_o~ ~s resdL~y f o r s o u b l s ,

Ths gros~os~ d~t f~ou~y in ~h~s extension uou~d bo the 8 v s t ~ -

b l l ~ t ¥ of ooupu~or emponsn~s. Ttn r e s o ~ o n I n ~s nsre3~y •

s ~ p ~ o loop snd a var~o~y o£ dL~feront t o m s or a oo1%oo of

d i f f e r e n t r o a o t ~ n s oen be added u separate c i r c u i t s uhioh

mm be Luoludod o1' oxe~udod a t p r o d o t o ~ d points In

s o l u t i o n . In o thor ~ r d s ~ sovers~ d~tferen~ n schs~sns fo r

~ho pe r t i nen t roaotton8~ eaoh st~nJ~J.un~ fo r var ious pres-

sures and ~enport turosj nsy be oona~dered e i m l t a n e o u s l y .

(Refele~o 33) has ~o~£de~ l tl~L~ probM but ~Lo~g ~,~o

3 ~ o e of h is studLo8 on • d~ssoc:La~ f l o v j and hi8 app rouh

can only be ocue~derod • p r e l ~ study.

-5o-.

Page 60: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

3. The s o n s ~ t t v ~ y ot the ooWosl~lon p r o t t l s ~o the reoonbina-

t ~ n ratM s u A o s t s thBt t h i s nay be • usstu~ nothod f o r exper~-

nsn~L~y n s ~ u r / J ~ tho vsluo of the reoombS~stlon r a t e . 8L~o

the oqu~/~a~un cons~snt i s ue3~ knoun and ths ~ o g nay be

estsbLtsbsd f o r • mssonabls period of t i m , the prob~nn of

~ m ' l n g the dgLooooiation r~ te and ix~4~el~.gLng ~ho rooomb4za-

flea eate Is ellsAasted. :he eoapositlon sat be measured ~se:r

FesetLae3r~v m p e ~ p i o a ) A F and ths ).or prsseums c~ns~dsmd In

t h i s s ~ are r s a d l ~ a t t~Lnab~ in the l abo ra to ry .

h . 8peeLfie nessls e o n t o m t o t p e r ~ c u l a r spp%les~cms can be

dos~nsd as an ex t su to , , ot tho emTint s~udy. Pae~leula~

r o l s ~ o n s h / p s bsWwn the v a r ~ u s psraus~ers osn be spec~-

t i e d and the r o s u ~ t l ~ noss l s contour doterainod. This s n s ~ -

s~s n~y u o ~ L~d~oato b e t t e r approaches f o r the m a s e r

of ssooubl~t~on r a t e than tha t suuos~ed above.

5. An 8 n s ~ g ~ s p u t e r a ~ o prov~dos a ~onvont~mt nsans fo r e s -

t ab l i sh ing d~soont/nu~t~os in a t l o v £~eld by suddon~ adding

a s tep r u n , ton (vol taSe) . Therofore i t wou~d be e o n v e n t ~

to usa I t f o r ths study of the e h m l u l r s a e t ~ n s o e e u r r ~ g

behind • s t rong noma~ shook w ~ s .

6. Ths speed of so~nd in a r s ae t / ng a l x t m ~s a tun~tlon of

r ~ o n r a t s and wou~d ~md l ~ t to study ~n a sannsr

s ~ d ~ a r to t h a t app14ed hsl~. ~n a d d i ~ , ths r ~ a t l o n s h ~ p

betlen so~le ~s loe i ty and the eeltleal veloeit~ at the

noss~e th roa t could be ~ .

Page 61: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

J j ' l~ l i l ) :~ A

• - 5 2 -

Page 62: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

.

.

Is.

.

.

,

.

,

0,

1.

2.

13.

Ilmprs~ A. J . , Jr. "One D~mnaLon~X i~Lmm ot sn 2aperteo~ D~8~on~o

]Mu, it. "Thornod~m£o 9 o s ~ ot 8upersonlo ]~pans~on Boss)~s snd C~ou~t4on ot ~mn~.opl.o BspoNnt t a r 0bm~os)J~ bao4Ani~ 0SNS. = va~o ~ e o ~ d m l Repo~ 57-~8~. 4u~y :L~6.

Rt~dU~n, V. D.j snd W. 8. C~oolmors. mA 8~udy ot Squ£~41br£u h s ~ Oss ~t tooU in lf~q~son:Le ~ r liosslos, Ino~ud£ni~ Cbar~ ot 1~ssmd:rmm~ Propert/m8 for Squ~ULta~Lm A/z." NASA ~M D-2~1,~

1960.

I~Lnlb C. It. "CompS3at~Lou ot ' ~ a e s , m d ~ o Proport~es~ Yransport Propelq~S~ and Yhooret~4mL~ P ~ o l ~ m o o of Oaoeous H~Niroilsn."

Wa£bors S . L . eHos~ &dd£~Lon to • One D~Jnsus~ms~L 8uporsc~o lr~og Znolud~ss ao8~ 0ss r,t~. m ~X)-~I .6~-lS0j September ~960.

l:qmur, 8. 8. Zut4,oduo~:~ou. t~ the $*,uds, ot Chromos). l t u ~ l o n s in FIov 8]ateali. AOAH) olP'spb 7~ But, tervori~he Solentff io Publio~tiono~ London~ 1 ~ 5 ,

Pemmr~ 8, 8, Per~mm~ Pross~ London# ~-9~'T,~----- - --- - --"

h S a s j 8. Y. "Etteo~ ot Os~en ~ o o o ~ a t ~ o u on 0no DSmns~onsl F~ov s t IKsh Huh ]lmbors. • L~CX 11 /~lJ~ January 19~;6.

Bt,~ JC. If. Co "~opsr~uro trou D£ssoela~n Equ~Lbrlun 2n 8 HFper- son~o Xoss~." ARC 19,98)~ Pareh ~7~ 19~;8.

Brays E. N, C. tA~u£o Roeoub£nst~Lon in s HpTorso~o Wind Tunnel ~ss~e." ARC 20~;62~ Novonber 2~ 1~8 .

FrNmSnj N. O. qonsquL~£bs~u Theory ot 8n Zdo~L D£ssoo£atbLng ()so Thmush a Con£oa~L Nossl,. • ARC 2Op~Oj a~us~ 5s 1~8.

Roiohenlboohp Roj and 8, 8. Penner. san Z4botrtt4vo Prooodu15 for tho 8o2u4dLon ot Noss~e F~Lov Prob~eam udL4~h Rmrs£blB Chem£oaZ Rosot4ons." t IT TeohndLos~L Report 28j Ms~V 1959.

LdLs T . T . Ulon S q u t ~ b r i m n o v in Oas Dynamos. w al~flR Tll S9- )89, ~ y 1959.

Drouue~ V, O. ~Jrbo Rooomb£na~Lon Prob~m in a Jet Ezbaue4b Nossle. m Z/t8 Paper ~;9-10~p Jtms 1959.

B2oomp H. H. and H. H. 8tmi4;or. eInv~oLd n o v ~_th Non Squ i l l b r lm Mo~cular DdLsmoo~Lon for Pressure Distr ibut ions Knooun*.erod In i~pereon~o F:Lt~t . , aS]X:-TS-~;9-~2, SevSeuber 1959.

Page 63: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

6.

17.

18.

9.

20.

21.

2,

lb~L~ Jo 0 . , A. Q. ~ohem.oodm'j and ,;. ,;. ![1.o£u. "Ctmd.u]. Won,. oqul~tw'J.un F, ffeoW on l~ych'ol[en Roolm~ ~ a m s t Lov Ps.~ammSo" CaL b p o r t AD-1118-,A-Si Imo,vombor 1.%9o

Oessnorj F. ao ~ J r . "Hon lkiull lbrtmt React4Lons in Sol:l~t. Propellant 08s Oenerator SystAms." 1KS i~oprint 10~6-60~ January 1960.

Reynoldoj T. ~.~ and L. V. ]~,,1~vJ.~, "One Dimnelonal Floe ~Lth Chenioal aeaot~on ~n Nosslo ~ x m s i o n s . " PrONnt~d 8~ ~ho IZCh]l ~]mpos:Lum on Thormodyna~oa of Jetb and Rocdml; Ps'opula£on~ Ms,y 1"/- 20, 1 ~ 9 ,

H a ~ J. O,~ and A. L, Ru~eOo "~tud£eo of Che~oa l Non Squi l£ba~m in l~pm~on£o NosLte Ylmm." CAL P.epos~ aD-ll l8.a-6~ liommber Z9~;9.

~bborj D, "~ndannual RepoTt on I m l t i ~ a t i o ~ of Ika ~o.uLlibrlmn Pl~nomna in Rool~i bmml~m. • ~ - 0 0 0 0 - O 9 1 6 8 ~ ~um ~10~ 1 ~ 0 ,

Woge~e~ P. P. "l~aauTement of R~te Coustantha of F u r b s o t 4 o ~ in & Supos.lon£o Nmsslm; u J oulq ~1 of G~me4Ml Ph3~_~_ae- Voltmo 28~ amber b~ Apr~ 1 ~ 8 . '

Weienel"j P. P . , J , E. lqartos and C, ThLele, ~Stud7 o f 8upenon£o

~bo aeaot~on s2"e20h'-2s02 8~ Log Reaetant Conm nm t t ~ n . " J~L Report 20-~9~ June 10, I~U.

23. Vopnere P, P. "Study of ~upo~onio Move v~Lth ChemLoal Rosat,2onss I I , 8UpeTeon£o ltosmZo Floe Tlth a Reaottng Oaa Mix~us~ at l~aotant Conoenta, ation," JPI, Repos"b 20-~70~ Deombe~. 19~ 1 ~ 8 .

2h. Olasstonep S . ~ o r e t ~ o a l CbenLstry. D. Van llostmnd Coups~ Ino.s Bog Zorkm 29~h.

25. Dole, X. Introduction to .S.tat£e,t,i,oal ~ W ~ t . Prentioe- ~lLls Ino . j Nov ][orkp 19r~.

26. lieLno s 8. P. ..Effoot~8 of Che~eal D£ssootation and Paleeular V4- brat~on8 on Steady One DiMnoional Flow. e ~ ~ D-87B August; 19~9.

27. LIEhI~Lllp M. J . a ] ~ e n of a D~osooLat;tng (]as." ARC 18~8J% ~ m n b e r l h j 1 ~ 6 .

28. Han~n, C. F. "£pproxlmat~ns fo r the Thermodynsmlo and ?rlmspo1% Properties of High Temperature A:Lt'." ILLCA 251 ~l~Op Karoh 1 ~ 8 .

Page 64: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

~O.

~7.

~8.

• m a , , s . v . ~ ~oun~t£ou of o ~ o a l x ~ e ~ . ~ , - a t l l Book Company, Inc. , ~ev ~ork, 1960.

l~l~man, S. "The Chs~oal ~ £ o s of A~ at l~h ~o~raturoo~ A Problem in l~:~rl;on:Lo £srodynss~oo." AV~O Rasearch Report, 1~ February 19~7.

Cuhel, ~. B., and B. II. Jennf~p. ~B..~. McOrme-P~L~I Book 0ompany, ~o., New ~ork, i~8.

C)s~, E. )1. ¢ . , and J. A. W£~,,an. "a P z ' e ~ Study of lon:l.o /leoembination of Ar&,on in Wind Tunnel Nossles.,' USA,a Beport 1.t~, Februa:7 ).P60.

N a t t ~ u 0 D . L . "lnter~eroms~vlo Mouuremn~ in the Shook Tube of the D~soolat ion Rate of Os~pn." The Physie~ o£ Flu£do~ V o l t a 2~ Numb~ 2~ Mash-April I~9.

VLI£1aM, T . J . 'q'be app).£oatJ.on of ~'~.o1~ Computere t,o Va~Lous Combustion, ~ and Fluid ~ s m ~ o Problems. n WADC Teohntoal ~ te 58-171, Juno 19~8.

LuVaZlej J. B. w and H. Cornel£u. "Teohn£oal Note on the Appl£oatLon of an Analog Computer to the anal~ie of ~q~rlmma~l Kine~to Data." Leos~.~ ~8-527, aura ]5, 1~8.

ICsle s O. A. man Anslol~ Ccmpu~r Study of Iyperson£o ~ £ ~ r Tm,leo- t~ox,Xeo uo~ug Pe~urbattou Te©bniqueo. n Uu£vero£tW of Hiohigsn b p o m , A u l ~ t 1960.

Nm~el, Z. "A Teohn£qm for AnaloE Rawuenta~ian of A~mospher~o b - e n t ~ Ua£nl Pmeturbat£ou ~ b o ~ . . ~n£nz~£tT of M£ohf4~n Rapo~, Aqust 1960.

Page 65: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

IPPigiO~[ !1

-56-

Page 66: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

A - lblmhol~s f s ~ emm~ (Chapter IT)

a 2- t~pLml d ~ t m ~ o moleoulo

D - dJ~m~4on~oe o o u t ~ , , (d~£nmd by EquabLon 2-15)

S - df~ooofatLon e n o r w

F - OlbIN t s ~ e n o r a ( ~ a p ~ r I I )

F - dLmsnm£on~so moomM~t ,£on m~o (do t i~od by Equst£on 2-20)

Ir - ota~lsU.os) . ~ £ g b t of the o~oL-,on£o ground s,,at, s

0 - d l m n s £ o n l u s equi l ibr ium m n s t a n t (defined bF Equation 2-21)

h - Planok~s oona~au~

I - n o l s o u l a r nonsn~ o t l n o r t £ s

J - d/asnslonlsss 'rJ.brablon fumotion (dotinsd I~ gquat:l~m 2-17)

k - B o l t s a s ~ s oonstant

k D - d lssoolst lon rate

k R - reoonbSns~on rat4

r p . equ£11brlun cons tan t bssod on p a r ~ s l p r e s s u r e s

m - p o ~ l e ~ m o o

n . ~ponou~ f o r moonbina~ton m ~

B - A v o 4 ~ d r o e s n ~ b o r

N . r o o i p r o o ~ of ~ho ~ a ros

p - p ~ o s u r e

Q - psrtt.~l.on funo~£on

r - stres~l.Lno ooordLuate

Page 67: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

R - u n £ v e r N 1 IPm o o ~ t ~ a n t

T - a b e o l u t o t o ~ o e r a t u r u

V - v e l o e £ ~ l r

O~ek 5]r'mboIjl t

OC - d l s o o o ~ t l m p ~ . a i W r ( d e f i e d I~, l qua t l on 2..~)

~, - d ~ i ~ n o o n m ~ t (defl.n~d bT S q u a t ~ Z-12)

v~- d tmM£on leoe m ~ a n ~ ( d ~ l d by ~l,~td.on 2-13)

9 - d ~ n e M £ o u l o m o e o u t a n t (dd~d bT ~q~a'~,£em 2 - 1 6 )

:l - o b ~ s ~ z d ~ t t o f r e q u e n a y o f m o l J ~ r v i b r a t i o n

- ~ m m u ~ f a o b o ~

4, - aboM.e speo£os

D - dJ.oeooJAtlou

• - equ£111~£~

e)Jo t - ol~ot~-onlo

M - m ) ~ e u l s r o i )oo too

R - ~ o o n b £ n a t £ o ~

r o b - r o ~ a t £ o n a ~

t r a n s - t m n s l a t l o n a ~

v £ b - v £ b r s t i o n ~

0 - r e f o m n o o condtt~Lon

S U l ~ r O ~ 4 p t ,

0 - s t a n d a r d o~a~o o f one a t m o o p h e r ~

Page 68: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

k~:~HDIX O

-.59-

Page 69: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

-6O-

Tsble C-1 l i s t s the Taluee of the p l~s las l constants used i n t h i s

study as r o l l as selected propert ies of : t z d is toa lo i~see, Although

o~gen has been usod fo r the spec i f i c solut ions presented berej t~e d l -

mnstonlos8 form of the equations allows seas iPmsrs l isat lon of t h i n

resu l ts to f l t other p, NSo

The choiss of the i n t t ~ l t e m p e r a t : i s d~floult 8rid doponds

upon the compositlon and pressure . Horo p e r t i n e n t to t h i s s tudy than

the ~ n t t l a l temperatu~s Is how f a r the i n i t i a l sompostt~on i s Erda an

oqu l l t b r i tm cc~oostt ion. Using the subscript oe to Indieate ths o q u f l / - t

br4.um composition a t the i n i t i a l pressure and t enpe r s tu re , ~ho o q u l l i -

brtum constant func t lon may be wr i t t en 8s

This oquatlon thus defi~os the I n l t l a l temperature m through the o q u i l l -

b r i m conotantm fo r a ~ p a r t i c u l a r e q u l l l b r l m oospos l t ion and i n i t i a l

p r @ s s U F @ o

Arblt~arlly the value of ~ oe has been chosen to be 0.50. The

t h r o a t pressure has boon chosen to be 28ta , B t h i s low preseure was

chosen oo t h a t the s o l u t i o n s could be a p p l i e d to current l a b o r a t o r y

8ysteus , most of uhlch have g lass CalSLI~ cbezd~rs upstream of the

nos s l e . For o x ~ p n , the correspondins teapera ture i s hOSOK. Thrm

d i f f e r e n t values of the ac tua l initial ooaposi t ion are s tudisdp one

above and one below equtJ.ibr'ltm and the oquilSbrtv~ emaposit lon.

AS discuHod in Chapter I l s there i8 considerable doubt as to

the cor rec t value of the recombination ra te fo r ozTpn . Ezsainat ion

Page 70: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

Gas

H

H 2

M

02 i

C1 , i

cz~

I.O1

2.02 | , ,

E/k

o K

26,000

52,000

o K

6,320

I x i0 ~0

2

o.b6

; i

2

¢ g

2

1

L N I~.o 56,5oo

_ N2 28.0 113,O00 3,~00 13.6 2 1

0 I 16.0 29,500 ' 5

19.2 2 ;32.0 59,000 2,270 3

71.0 28,800 813 108 2 1

80.0 lz,~oo

~3

Br

~65 0 l

2 1 22p800

8,950

Br 2 IbO | i

127

Z 2 254 17,900 309 7k2 2 j l

h = 6.62 x 10 -27 erg sec/particle

N = 6.02 x 1023 particles/Ea-aole

R - 8.31 x 107 ergs~K ga-=ole

k - 1.38 x 10 "16 ergs/°K particle

1 - erg sec2/ga ca 2 - I.O1 x 106 erg/ca 3 ata

TABLE C-I Gas Parau.st~rs

-61-

Page 71: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

of the recombinat ion r a t e funct ionp Fp shows t h a t the i n i t i a l va lue of

the r e c o a b i n a t i o n r a t e occurs as the product of r o ~ ( T o) and ~hat t h i s

i s the only place t h a t the c h a r a c t e r i s t i c l eng th appears , Thersfomp

any change in the magnitude of the recombinat ion r a t e a t T O can be e x a c t l y

compensated fo r by r e d e f i n i n g the value of r o. The r e s u l t i s t h a t only

the temperature dependence of the recombinat ion r a t e f u n c t i o n need be con-

s ide red° The value o f F has been chosen to he unityp a va lue t h a t O

c o = ~ s ~ s to r o - 1.o7 ~ ~ d ~ ¢T.) - 8.L x 10 ~ ¢ T / 3 5 ~

gin-mole "2 see "1 ( the value p r e d i c t e d by Matthews in Reference ~ ) ,

Seven i n t e g e r va lues of the temperature exponent i n the recombinat ion

rate were considered, -3 ~.n ~- + 3, Table C-2 su,unarises the initial

conditions °

The c r i t i c a l value of the v e l o c i t y , Vo, i s d i f f i c u l t to c a l c u l a t e ,

However, for t h e computer i t i s very simple to determine i t s value on

a t r i a l and e r r o r b a s i s , s ince i t appears only twice as a c o e f f i c i e n t

andp as a r e s u l t of the p a r t i c u l a r no i z l e contour chosen, only one of

these coefficients is initially important, Therefore, ~ is set by

adjusting its value until the derivative of the area is serop the ca-i-

t e r i o n f o r the nozzle t h r o a t ,

Page 72: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

PO " 2Mm.

OCoe " 0,$00

T - 60501 Q

F • 1,00 O

0 - o.333 O

" 0.560

O - ~ . 6

Jo " 1.33

CASB u n n n

Z

I I

I l l

%

0.500

0.667

0o333

I I I I nn I

0.667

0,600

0.750

8TJBOJI~Z |

A

B

C

D

B

P

0

n

- )

t2

-1

0

TLBLE C~! I n i t i a l Condi~ione

-63.-

Page 73: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

~ Z X D

a.~,,1.~ O-~nuter Pro~

Page 74: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

She act ive olmmnt analog omputor j or e lect ron ic dt .~forsnt ia l

m~lTsmr9 oormtaW of a co l lec t ion of high Sain v o l t a p mmplf~iers w

venta~orsp oapaottorsp and oervo~tore arranged in ouch • oonftgu~ation

that the v o l t a p 8 throughout the c i r c u i t behave i d e n t i ~ as the

phy84osZ pal~motel~l in tho d l f£e l~n t ta l equations being 8oZved. The

e l :cuLt i s N t up by ecubinir~ a nunber of i n t e g r a t o r s , susmors, and

nul t lp lXero in a clomd loop ouch t h a t the spot•rictus on the v o l t • p c

oozqmopond to thorn required by the d i l f e r s n t t a l equat ion.

b u 4 c eZenent of the analog eomputor i s a high gain (approxl-

]l~te~, wJ~lO~Oj)CX~) ~p~4~i~ro ~][~ ~p~4411l~r has ~ ~hJrsctl~Jrist~Lc of

/nvorM~g the ai4~n of the v o l t s p being DpZiZied and may be assumed to

have • nagZ~Lg~.bZe current fZow through i t . Figure D-1 shores how t h i s

un l t coupled ~Lth NrlLos J.~out mststanoos 8rid e i ther • £oed1~tck mo le -

tame or ospsoitanoo ~ n be used to add or in te i~s to • v o l t a p . Z n l t t s l

~ud i t t ons a n N t t~ ~Lnpo~lng sn 1nit1•1 vole•go on the u p e o t t o r .

App31ostlon of Etrohof£s lave to the c i r c u i t of the smms~ l~Sulto in

tim output v o l t ~ p being equal to

I f the ampLtftJr MAnp AB 1o l a r p msough tM8 ~ be approximated by

- ~ o

£ o i m l ~ mml~'sts of the i n W ~ t o r m~d a mtmtlar approximation shows

tdmtp In t h ~ CaNe

Page 75: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

Ro

R I

e~ e o

et

. . L R=

" - S U M M E R

" C

I

Ri e, e o

. . .L - J - m m

• D

INTEGRATOR

BASIC COMPUTER COMPONENTS

FIGURE D-I

- 66 -

Page 76: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

-67-

t f

~° C9., ,u Q

The nes t 8 t~n i f t oan t f ea tu re of these t ~ :moults le t ha t the s m p l t f t e r

oharactmriet io8 do not appear and the gain of the c i r c u i t to s funct ion

on~y of the ex te rna l o l o o t r t o s l component~s.

Another bu4o oonponont used i n analog computers le the 8Ol, VO-

multip3.tor. This un i t oonslet8 of • number o£ o ~ L m ~ r ~ po~ontiomo~om

dz~von by • gozs~motor, (}no of the potonttomotor8 i s oonnoetod to •

l ~ e m n o o 8upp~ and foods I t8 output bask to the Nrvomotoro The

~ t o r pog~t4one i ~ l f so t h a t the input vol tage le Jus t balanood

by ~h~J £oedbsok voltm~o. In o ther gomdep osoh follow up potentlomotor

JJ pos i t ioned go t h a t I t s output i s deomaood in propo~lon to the r e t i e

of the e e r v ~ o t o r dx'i~lLnl; vol tage to the roferenoo Tol tage. Thusj one

func~4on nay bo mult4pliod by a8 manV other funs• lone 88 tha l~ are

fol low up po~onttomo~ows. Mul t ip l i e s • ion by • sons ,ant eoo.Bfiolont tg

• coomplished by feeding the v o l t a p through • p o ~ t i o m o t o r and ~apptng

off the l~qui :od person•see, Tht8 constant ooof f to lon t must the1~fo15

a l l y s be los s than un1~7.

Fl~u:o D-2 shows the Gomputer s~mbols used In t h i s FOpOl~o

F i g s D-3 shows • nunbor of bas le oonf~ura t ion8 used to pes'fos,at s

number of common OpOl~tione. Solving f o r e o ~n the d iv i s i on o t~oui t

eo ~ -- los --~' - tO0 ~.,

I f the amplif~or gain i8 su f f lo ion t lw h~h~ the oooond torn u n be

Page 77: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

SUMMER

el , ~ . ~ h ~ , , ~ ~ - o e , - b e = e=

el (0 )

el -o e~ dt

SERVOMULTIPLIER

e, eoO, I00

POTENTIOMETER

.,__Q o < 1

oe,

REFERENCE VOLTAGE TIE POINT

Q ©

COMPUTER SYMBOLS

FIGURE D-2

- 68 -

Page 78: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

e,

I00

eo

DIVISION

e, z

- e I eo

SOUARE ROOT

- o e o

e, / ,~ d,

DIFFERENTIATION

BASIC COMPUTER CONFIGURATIONS

FIGURE D-:5

- 6 9 -

Page 79: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

-?0-

h e i s t e d and

C o = - ~00 ~--~

S ~ 3 ~ r ~ y . f o r the square ~oot o iz~u i t

~ o : %00

The d:Lfferent~ation ci~ou~t ~8 only an approx~natlon and. as such# ~s

genera l ly not reeonnonded. Solving for the vagus of % .

d e , ~ Co

F~" v ~ s s of a ~ r o a c h l ~ ~'~.tym th l e oesion e p ~ , o x ~ a ~ e t ~

du~vat~ve ~ c lo se ly .

e)Jotronie analog oomputer nay be used ~o solve 8 vat /s ty of

eni~nee~JLni; problem (see Itefe~noe8 3~-38). Zt to best suited fo r

solving systems of ordinary d~f ferent$~ equations desm'iblns inStIA1

oondi t ion p r o ~ ; hovsvor, i t ms7 bo used on non i n t t t s I oondt t ion

prob)Au8 or even sore pe t r i e1 d : L f f e r e r ~ equat ions ,

I nuaber of r e s t o r e n u t bo ca r e fu l l y cono4dered in preparlng a

probhm f o r solut40n on a computer. As evidenced by the p~v~ous d4s-

o~usslon~ the independent vs.-dab, s fo r the ~ u t e r Is time D and a l l of

the dependont var4.ables are vo l t egss . ?h~Ls neee s s l t e t e s scaling of e 33

of the physioal v a t , h i e s i n term8 of volta~SSo Most oonputer ooapo-

nsnts are designed to operate l i n e a r l y f o r v o l t a p s botvoen 0 and * XO0

vo l ts . Therefore a 33 tho m b l o s should be eoalod so t h a t tho i~

absoluto value i s l e s s than 100 w i t s throughout the e n t i r e so lu t i on .

Page 80: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

-71-

(The PACE eomputoro used in t h i s study hays an autocratic overload i n d i -

ca tor to stop the so lu t ion i f a t any time any v o l t e ~ exceeds 100 v o l t s . )

In ordoF to ~ s OlTOr8, i t i s ~sIJc'•bk to k ~ p the v o l t a p 8 as

l a rge u possiblep p a r t i c u l a r ~ in sub t rac t ion opera t ions . Scal ing the

t~m fo r the so lut ion presents d i f f e r e n t oonsidemtions. Long t i r os

allow orrors to aoomm~ate u a resu l t of ampl i f i e r d r t f t p s a p • e l i o t

l a a k a p p StOop ~mroa8 shor t t t m u produce orrorsp s~uce tho uapacitozw

have ~ inherent time constants and the Nrvomul t i p l i e ro w i l l t rack

n m t i s f s o t o r t ~ up to a p p r o x , • r o s y 1 spa. (For f a s t e r so lu t ions non-

mechanical eleotronie m u l t i p l i e r s may be ueodj but they are loan depon-

dabls and l s s e aoou,'mto than N r v o m u l t i p l i e r u . )

The form of the equations and the sequence of operat ion i s of

considerable impor~ance in t h e i r so lu t ion . I d e a l l y j the equations should

be cas t in 8 Nlf -oompensat lng formj tha t i s s fop a deormmlng funot lon

tho de r iva t i ve should be equal to the negat ive of the va r i ab le ti,IB8 •

pos i t i ve funot ic~ . This formulat ion has • ~ndon~r to c o z i e r i teml~

in t h a t i f the ver~able i s too l a rge , i t cor rec t s i ~ l f by ad ju s t i ng

~m ~ r i v a t t v e to componmak. E f f e c t i v e l y t h i s approach forces a l l

e r ro r s to o s c i l l a t e around the proper so lu t ion r a t h e r than con t inua l l~

increase am the so lu t ion progFosces. A u r t o u 8 d i f f i c u l t y oeeu~ i f

t~m problem Invelves the d i f fe rence of two values of rmarly equal magni-

tude. In addltlon to the fast that mall error8 am ~agnlfied ~n th~

operatlon~ the oh•raster of the solution may ehan~ Fadloally if the

error is sufficient to ohsnRe the algob~ale sign of t.he result. This

l a t t e r d ~ f t i o ~ 7 may be rmmvad i f the nature of the problem i s such

Page 81: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

-72-

tha t the o o m o t eigu f o r t h i s m a l l vol tage i s knmm. In t h i s ease

the r e s u l t m y he foroed to he oor reo t by f eed ing i t through a diode

or by dr~ving a s e r v o a u l t i p l i e r and a l lowing I t to respond in one d i r e c -

t i o n on~y. l n s p e o t l o n of the d lv~elon o l r o u l t shows t h a t the aocuraoy

I s s e r i o u s l y a f f e c t e d I f the d i v i s o r I s a ve ry m a l l number, even though

the q u o t i e n t may be l e e s than I00 v o l t a .

The s e t of e i g h t s4,nultaneous d i f f e r e n t i a l equa t ions d e s o r i b i n g

t h i s problem of a r e a c t i n g nosz le f l o v have been s e t up f o r the computer

s o l u t i o n and are presen ted i n Chapter I l l . I n speo t ion of these equa-

t i o n s shove that they are s e l f nompenseting as mush as poss ib le . The

re&ot4on equa t ion oontatno the d i f f e r e n o e between two n e a r l y equa l

q u a n t l t i e s p the d~ffezwnce be tvsen them be ing p o s i t i v e or n e s a t l v s de-

pending upon the d e v i a t i o n from e q u i l i b r l u a j and a l s o j the a rea funo t lon

s t a r t s a t zero and than i n o r e a s e s . The f i n a l prosren i s shown i n

F igures ~ and D.hB. I n s p e c t i o n shove how these problems were olrcmn-

vented In t h l s ease , The a rea funet lon~ I ~ tiN/dr, d r i v e s a sszwomul-

t l p l i e r ~ a l l o ~ n g only nega t ive valuaep e lnos the s o l u t i o n s t a r t s a t

the n o b l e t h r o a t where t h i s f unc t i on i s l d e n t t m ~ l l y ze ro . The d i f f e ~ -

enos between the two near]~v equal q u a n t i t i e s has not been ad jus t ed m

o t h e r than mhxL~sing the vo l t agssp p r i n a r L l y as a r e s u l t of l e ek of

computer oomponent~. The ohotoe of the r e c i p r o c a l of the area~ N s as a

oomputer v a r i a b l e was made to formulate a s e l f oompensatin8 equa t ion as

v i i i as g i~ ,ng i t a mud~um value a t the beginning of the s o l u t i o n ,

The oholoe of p/T as a v a r i a b l e m made to reduce the r a t e of e h a n p

of p ressu re and glve nero seourete m o u l t s . The ehoioe of d ? / d t - -T 2

Page 82: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

!

L~

I

¢ ~ " ~ . _ _ _ _ ~ , ~ n<o '=0

~__ d_..V.V" tOO I:-"T dt~VL/ I0o Va at

• ,~ ~ 0 _ _ ~ / ' 3

Z I"=

d t , ~ ~5oG

do~ i d~

d ~ * dt d~.

dV L

a~

i I

I dK -too ~.o¢ dt

- 5 , o o o P t d

~ T[.Ioo , ~% a t

, 5 E-r v =

,_ ~'~"L N d t ~4~. * .~ ,., a t dK

~at ~ dt

0

- I ~ - - ~ L T

~ V L dt

FIGURE D - 4 A COMPUTER PROGRAM

Page 83: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

I

I

i +0( *-~EX

o----@ * So

-~* , ~ _ 6_.~ i D d ~

~t . ~ 50 d t

_ L _ t.

I0,000

I +__ T ~

I~O00

d=(

d r .

I 1-

IOO d t

I |00 ,-Or.. Z z.

I , 1 0 o r ± d'~z ~oo.t K d t

i ocT ~ I00,00o

i@

ioo+ I dq~

T{ iOo .i i ) dt ~ ' ~ I00

I00, 0 0 0 I 00 ~t.

dt

do~

+ 5 ~ T ~ - ~' T I o o 3 o o o i ,ooo

-~oc dt

-zo d3 V T ~

_ _ _ _ _ d J i d 3

-Z0J (J,=)

i T L + 1 , 0 0 0

• ~oJ , ~ - ~ t J + , } -4J U,,) *2OJU, , I

FIGURE D-4B COMPUTER PROGRAM

Page 84: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

f o r the independent var iab le funct ion was made to m . ~ l a l ~ the number

of computer components nooouary fo r the problem so lu t i on , NOVOl~lO- I I

l o n , . t~s problem requtawd the fo~1o~ng eo~oonents

8 - l n t e g r a t o ~

2~ - Sum~ng J~mpl~Lfte~

8 - Se~vomult tp l~rs (18-Nparato m u l t i p l i e r c i r c u i t s )

27 - Pc•on•tome•ere

2 - 8~ tches

F l g u l w D-~ i s a reproduction of • sample so lu t ion to the oct of

d i f f e l ~ n t i a l equat ions . I t i s the output of • s ix chem~ll Sanborn

Recorder, I~spi to the f a s t t h a t the p r o ~ lure boon opttmtMd ~o

minJxtse e r ro r and the actual components e ros i s to l5 and ospsottonsp al, o

aocuna~o to 0,1 par sent and onoloNd in • t h e z ~ m t t c a l l y con t ro l led

ovonp e r ro r s u ~ •coumu~t4 end mus~ bo ohocimd, Although • complete

el~Or ana lys i s 18 out of the quostLon fo r • probleu ~his oonplezj •

VOlT good check on ~ •sour•oF £8 afforded t h r o u ~ the f a c t t ha t the

equation of s t a t e n~y be intoK~atod. Zn o ther wordap the ez~or i8 •

dilwot func t ion of hog close ~ 8 fo l log tng ~dontt ty £8 s a t i s f i e d

= t

Y ~ u r o D-6 shams hey c lose ly the so lut ions obta4nod In t h i s study sstLsFF

t h i s ros t r io t4ono The curve presented roprooen~s the average of • nunbor

of so lu t ions° Ccaparison ~l th Figure D-~ 8hou tha t the accuracy i s

gel1 ~ t h i n the l ~ u t t s u~th which the eonputer output can be road. Tbo

sharp increase in e r r o r a t the l o m r temperatures ~8 caused by the mmll

Page 85: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

4- 0.6

d= dt

0

- 0 . 4

+ 2.5

&CX

0

- 2 . 5

1.0

N

0

I.O

.E T

0

I0

V 2

!.0 0

i.0

T

0

60 SECONDS

FIGURE D-5 SAMPLE SOLUTION

- 76 -

Page 86: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

1.10

1.00

0.90,

0.80,

0.70.

0.60,

0.50" 1.00 0.80

\

0.60 0.40 TEMPERATURE

0.20 0

FIGURE D-6 TYPICAL ERROR

- 7 7 -

Page 87: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

-78-

values of most of the palwmo~rra and the ro su l t i ng l n a o ~ Of nsadins

the da~a. lSmmverw ainoe tho me, or ~n~ereat 1o oentered upon ~ o t n l ~

por t ion of tho | o l u ~ n p t h i s prooonto no major problmmo

Page 88: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

• t

API"SNDIX lz

Oomput4r 8o.lut, J.one

-79-

Page 89: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5 .0

T o = 4 0 5 0 K

Po = 2 a t m .

¢x o 0 . 5 0 ~ n = + 3 ~ =

2.0 , ~ I , , ,

1 1 . 0 '

0 .2

0 . 1 ' 1.0 0 .5 0 .2 O. I 0 . 0 5

P R E S S U R E

NOZZLE FLOW PARAMETERS, CASE I A

FIGURE E-I

- 80 -

Page 90: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0

2.0

I

To = 4 0 5 0 K

Po = 2 otto.

=o = 0.50 n --:3

0.5

0.2

0.1 1.0 0.5

NOZZLE FLOW

| 1

0.2 0.1 0.05 P R E S S U R E

PARAMETERS, CASE TB

FIGURE E - 2

- 8 1 -

Page 91: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0 T O = 4050 K Po = 2atm. uz _ . . . ~ ~ ao= 0.50 n = + 2 J

2.0 t

I,O ~

0"51 ~ ~ ~

,

0.2

0.1 1.0 0.5 0.2

PRESSURE

O. I 0.05

NOZZLE FLOW PARAMETERS, CASE IC

FIGURE E- 3

- 8 2 -

Page 92: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0

2.0

1.0

0.5

0.2

0.1

To = 4050 K Po = 2 a t m .

=o = 0.50 n - + l J

1.0 0.5 0.2 0.1 PRESSURE

0.05

NOZZLE FLOW P A R A M E T E R S , CASE I E

F IGURE E - 4

- 8 3 -

Page 93: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0

2.0

I

T o - 4 0 5 0 K

Po = 2 atm. m o 0.50 . - - I ~

"Jl

V 2

0.2

0.11 1.0 0.5 0.2 0.1 0.05

PRESSURE

NOZZLE FLOW PARAMETERS, CASE TF

FIGURE E- 5

- 8 4 -

Page 94: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0

2.0

I

To = 4050 K Po = 2 atm v2 ~ ao= 0.50

n =0 J l

S f

0.5

0.2

0 . 1 L

1.0 0.5 0.2 0.1 0 .05 PRESSURE

N O Z Z L E FLOW P A R A M E T E R S , CASE IG

FIGURE E - 6

- 8 5 -

Page 95: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0

2.0

1.0

0.5

0,2

0.1" 1.0

T o = 4050 K Po = 2 atm.

a o = 0 . 6 6 7

n = + 3

I ,---a..

Lv

0.5 0 .2

PRESSURE

! I

0.1 0 . 0 5

N O Z Z L E FLOW P A R A M E T E R S , CASE TrA

F IGURE E - 7

- 8 6 -

Page 96: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0

2.0

T o = 4 0 5 0 K

Po = 2 otto.

o¢ o = 0 . 6 6 7

n - - ' 3 ~ f

j f

0.5

0.1" 1.0 0 .5 0 .2 O. I 0 . 0 5

P R E S S U R E

0.2

NOZZLE FLOW PARAMETERS, CASE 11"B

FIGURE E- 8

- 8 7 -

Page 97: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0

2.0

T o = 4 0 5 0 K

Po = 2 arm, i = o¢ o - 0 , 6 6 7

0.5

0 .2

0.1 1.0

| |

0.5 0.2 0.1 0 . 0 5

P R E S S U R E

NOZZLE FLOW PARAMETERS,. CASE Tr C

FIGURE E- 9

- 8 8 -

Page 98: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0

2.0

T o = 4 0 5 0 K

Po =2 atm. = 0.667 (X o

n = + 1 ~

J 0.5" "

0.2

0.1 1.0 0.5 0.2

PRESSURE O. 0.05

NOZZLE FLOW PARAMETERS, CASE Tr E

FIGURE E - I 0

- 89 -

Page 99: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0

2.0

I T O = 4 0 5 0 K

Po - 2 otto.

. __ ~

f

S 0.5

0.2

0.1 1.0 0.5

I

0.2 0,1 0 ;05 P R E S S U R E

NOZZLE FLOW PARAMETERS, CASE TrF

FIGURE E-I I

- 9 0 -

Page 100: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0

T o = 4050 K Pa = 2otto.

= 0.667 ~ ~ - O( o

n = 0

~o~ - - ~ /A

0.5 " ~ r ~ '

0.2

0,11, 1.0 0.5 0.2 O.

PRESSURE

|

0.05

NOZZLE FLOW PARAMETERS, CASE TrG

FIGURE E-12 - 9 1 -

Page 101: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0

2 ,0

1

= 4 0 5 0 K

Po = 2o t to . ~,2 ~

ot o 0 .333

n = + 3 1 J

S , o

r

0.2

O.I • I I

I.O 0 .5 0 .2

P R E S S U R E

0.1 0 . 0 5

NOZZLE FLOW PARAMETERS, CASE TITA

FIGURE E-13

- 9 2 -

Page 102: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0

2.0 . = - 3 ! ~

S ,.o

0 . 5

0 .2

0.1 1.0 0 . 5

i |

0 .2 O. I O. 0 5 P R E S S U R E

I T o = 4050 K

Po = 2 otto

¢x o = 0 . 3 3 3 ,,,

NOZZLE FLOW PARAMETERS, CASE "rrr B

FIGURE E-14

- 9 3 -

Page 103: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0

2.0

I T o = 4050 K Po " 2 otto. (x o • 0.333 n - - + Z ~

0.5

0.2

0 . 1 u 1.0 -0.5 0.2

P R E S S U R E

NOZZLE

0.1 0.05

FLOW PARAMETERS, CASE TIT C

FIGURE E-15

- 9 4 -

Page 104: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0

T o = 4 0 5 0 K

Po = 2otto. v 2 ~

=o 0.333

2.0.i n = +t J

1.0

0.5" ~

0.2

O.i 1.0 0.5 0.2 0.1

PRESSURE 0.05

NOZZLE FLOW PARAMETERS, CASE Trr E

FIGURE E-16

- 9 S -

Page 105: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5.0

2,0

1.0

0.5

0.2

0.1

I To : 4050 K Po : 2 otto.

(x o 0.333

n =--I l J

f

1.0 O. 5 0.2 O.

PRESSURE

0 .05

NOZZLE FLOW P A R A M E T E R S , CASE I E F

F I G U R E E - 1 7

- 9 6 -

Page 106: The effect of recombination rate on the flow of a dissociating … · ABSTRACT The flow of a chemically reacting ps through a diTergent nossle Is considered. £ pure diatomic gas

5,0

2.0

0.5

I T O = 4 0 5 0 K

Po = 2 arm.

a o 0 . 3 3 3

° ° ~

S

0.2

0.1 1.0 0 .5 0.2 O. I 0 . 0 5

P R E S S U R E

NOZZLE FLOW PARAMETERS, CASE ]]I G

FIGURE E-18

- 9 7 -


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