An timisting Fuel System Kerosene JT3 Engine Integration Study

7/17/2019 An timisting Fuel System Kerosene JT3 Engine Integration Study

1/48

-.

I

N A S A Contractor Report 4 33

I

An

timisting

Fuel System

Kerosene

JT3 Engine

Integration Study

A.

Fiorentino

CONTK CIb N A b3 - 2 4 2 17, N A S3 - 2 4 3 5 3 ,

and D T F A 03-8 1-A-001 54

J A N U A R Y 1987


2/48


3/48

PREFACE

T h i s r e p o r t d e s c r i b e s th e work c o n du c te d by t h e P r a t t 8 W h i tn e y E n g i n e e r i n g

D i v i s i o n

o f

U n i t e d T e c h n ol o gi e s C o r p o r a t i o n t o a s s i s t NASA Ames-Dryden F l igh t

Research F a c i l i t y i n t h e i r p r ep a ra t io n for t h e F u l l - s c a l e T r a n s p o r t C o n t r o l l e d

I m p a c t D e m o n s t r a t i o n T e s t .

T h i s e f f o r t was s po n so re d b y t h e N a t i o n a l

Ae ro na ut i cs and Space A d m in is t r a t i o n under Co nt ra c t s NAS3-24217 and NAS3-24353

and f unded by t he

F A A

t h rough I n te ragency Ag reemen t No.

DTFA03-81-A-00154.

The au thor w ishes t o acknowledge the gu idance o f

M r . L .

Dean Webb o f N A S A

Am es-Dryden F l i g h t R e s ea rc h F a c i l i t y whose k ee n i n t e r e s t a nd s u p p o r t we re

p a r t i c u l a r l y i n s t r u m e n t a l

i n t h e s u c c e ss fu l c o m p l e t io n of t h i s s u p p o r t p r o g r a m .

m m AGE BLANK

NOT FILMED

iii


4/48

TABLE OF

C O N T E N T S

S e c t i n

P R E F A C E

SUMMARY

I N T R O D U C T I O N

E Q U I P M E N T

AND PROCEDURES

E n g i n e D e s c r i p t i o n

Engine Fuel System

Fuel Pump

F u e l C o n t r o l

Fuel F i l t e r Systems

Combu

s

t o r

De

s

c

r

i

t

i

n

E ng in e M o d i f i c a t i o n s f o r

AMK

B-720 F l i g h t T e s t E ng in es

F A A Techn ica l Center Ground T e s t Engine

L a b o r a t o r y

F1

ow Ch ar ac te r i za t i o n Equi pmen

t

Fue l

S y s t e m

a n d E n g i n e O p e r a b i l i t y

F u e l C h a r a c t e r i z a t i o n T e s ts an d A n a ly s e s

Engine Per formance

RESULTS

AND

D I S C U S S I O N

CONCLUDING

REMARKS

A P P E N D I C E S

Appendix

A

JT3C-7 Engine

Appendix B-1

Appendix 8-2

Appendix C

Procedure

f o r

D e te rm i ni ng F i l t e r R a t i o

Procedure for D e t e r m i n in g t h e T r a n s i t i o n

V e l o c i t y A Measure

o f

AMK D e g r a da t i on L e v e l )

T r a n s i t i o n V e l o c i t y and F i l t e r R a t i o A pp ar at us

REFERENCES

i v

Page

iii

1

1

2

2

4

4

4

9

9

10

10

17

20

20

20

23

27

31

32

38

40

42

1

43


5/48

SUMMARY

An a n a l y t i c a l s t u d y and l a b o r a t o r y t e s t s w e r e conduc ted

t o

a s s i s t NASA i n

d e te r m in i ng t h e s a f e t y and m is s io n s u i t a b i l i t y

o f

t h e m o d i f i e d f u e l s y st em and

f l i g h t t e s t s fo r t h e F u l l - s c a l e T r a n s p o r t C o n t r o l l e d I m p ac t D e m o s t ra t i on ( C I D )

Program. Th is 12 month s tu dy rev iewe d and ana lyz ed bo th the use of a n t i m i s t i n g

kerosene ( A M K ) f u e l a n d t h e i n c o r p o r a t i o n o f a " f u e l d e g r a d er " o n t h e o p e ra -

t i o n a l a nd p e rf or m an ce c h a r a c t e r i s t i c s o f t he e n gi ne s t e s t e d . P o t e n t i a l

d e f i c i e n c i e s a n d / o r f a i l u r e s w ere i d e n t i f i e d and a pp ro ac he s to accommodate

t h e s e d e f i c i e n c i e s w e r e recommended t o NASA Ames-Dryden F l i g h t Research

F a c i 1

i

y .

T h e r e s u l t s o f f l o w c h a r a c t e r i z a t i o n t e s t s on degraded AMK f u e l s a m p l e s

i n d i c a t e d l e v e l s o f d e g r a d a t i o n s a t i s f a c t o r y fo r t h e p l a n n e d m i s s i o n s o f t h e

6-720 a i r c r a f t . The o p e r a b i l i t y and pe rf or ma nc e w i t h t h e

AMK

i n a g ro un d t e s t

e ng in e and i n t h e a i r c r a f t e n gin es d u r i n g t he t e s t f l i g h t s were c om parab le t o

t ho se w i t h u n m o d i f ie d J e t A . For t he f i n a l

C I D

t e s t , t he JT3C-7 eng ines

p er fo rm ed s a t i s f a c t o r i l y w h i l e o p e r a t i n g on AMK r i g h t up t o i m p a c t .

I N T R O D U C T I O N

I n

a

t y p i c a l a i r c r a f t c ra sh , f u e l s p i l l e d f rom r u p t u r e d f u e l t an ks forms a

f i n e m i s t w h ic h can be i g n i t e d by a number o f s ou rc es a t t h e c ra s h s i t e .

I f

f o r m a t i o n

o f

t h i s m i s t can be suppressed, f i r e hazards can be reduced and

l i v e s can be saved. FM-9, a h ig h mo lecu la r -w e igh t , l o ng ch a i n po lym er , when

b le n de d w i t h J et -A f u e l i n c o n c e n t r a t i o n s i n t h e ra ng e

o f 0.3

p e r c e n t b y

w e ig h t, ha s d em o ns tr at ed t h e a b i l i t y t o i n h i b i t

i g n i t i o n and f la me p r o p a g a t io n

o f

t h e r e l e a s e d f u e l i n s i m u la t e d cr as h

t e s t s .

T h i s a n t i m i s t i n g ke ro se ne (AMK), when subjected t o t h e s h ea r l e v e l s e x p ec t ed

i n a i r c r a f t e ng i n e sy st em s, c an ha ve u n d e s i r a b l e f l o w c h a r a c t e r i s t i c s s u c h a s

p oo r f u e l a t o m iz a t io n and f i l t e r a b i l i t y . Th is p r ec lu d es

i t s

d i r e c t use i n a

g as t u r b i n e e n g i n e b e ca us e

o f

p o s s i b l e c l o g g i n g

o f

f i l t e r s , u n a c c e p t a b l e s p r a y

q u a l i t y

o f

f u e l n o z z l e s / i n j e c t o r s and redu ced h e a t t r a n s f e r c o e f f i c i e n t s i n

f u e l hea t exchange rs (Re f . 1 ) . The re fo re , t he

AMK

f u e l m u st be a l t e r e d

t o

r e s t o r e

i t s

p a r e n t J et -A p r o p e r t i e s for p ro pe r o p e r a t i o n i n t h e e n gi ne f u e l

system.

F u el a l t e r a t i o n c an be a c co mp li sh ed b y t h e a p p l i c a t i o n o f s u f f i c i e n t m o l e c u l a r

s t r e s s

t o

r u p t u r e t h e p o l y m er i c a d d i t i v e c on ta in ed i n t h e AMK. T h i s p r o c e s s o r

a l t e r a t i o n

of

t h e

AMK

f u e l

i s

r e f e r r e d

t o

as " de g ra da t i on " . The t e ch n i ca l

f e a s i b i 1

i

y o f d e v i c e s d e s i g n a t e d " de g r ad e r s" w h i c h u t i 1 i z e e i t h e r m e c h a n

or

c a v i t a t i o n p r i n c i p l e s ha s been de mo ns tra te d ( R e f s.

1 ,

2,

3 ) .

Th i s r e p o r t documen ts a twe lve -mon th

AMK

E ng in e S ys te m I n t e g r a t i o n s t u d y

e v a l u a t e d t h e u s e o f a n t i m i s t i n a k er os e ne and t h e i n c o r p o r a t i o n o f a " fue

c a l

h a t

d e g ra d e r" o n t h e b e r f o r m a n c e , re1 a b i 1i y and s a f e t y

o f

t he P r a t t & Whi tney

JT3C-7 engines for s h o r t d u r a t i o n f l i g h t s o f a B-720

t e s t

a i r p l a n e d u r i n g t h e

F u l l - S c a l e T r a n s p o r t C o n t r o l l e d I m p ac t D e m o ns t ra t io n ( C I D ) P ro gra m h e l d a t t h e

D ry de n F l i g h t R e se ar ch

F a c i l i t y

o f

t h e NASA Ames Research Ce nte r . T hi s s tu dy

was co nd uc ted und er co n t r a c t s NAS3-24217 and NAS3-24353 and fo cu se d on two

1


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major a reas of a c t i v i t y : T a s k

I-

y st em I n t e g r a t i o n St u dy a n d Ta sk

I 1 -

Des ign

R ev ie ws and F l i g h t T e s t P l a n n i n g .

I n Task

I f

th e program, a rev ie w and an a ly s i s were made

o f

the JT3C-7 AMK

eng ine f ue l system wh i ch i nc l ud ed t h e deg rade r system, hea t exchange rs , eng ine

f u e l pump and f i l t e r s , f u e l c o n t r o l s a nd t h e r e s u l t i n g o p e r a t i o n a l a nd

p er fo rm an ce c h a r a c t e r i s t i c s o f t h e e n g i n e s . T he 8-720 i n s t r u m e n t a t i o n was

re vi ew ed and recommendations were made for a d d i t i o n a l d e g r a d e r a n d e n g i n e

i n s t r u m e n t a t i o n

t o

i d e n t i f y p ro b le m s t h a t may o c c u r .

As

p a r t o f the Task I

f f o r t ,

l a b o r a t o r y f u e l c h a r a c t e r i z a t i o n t e s t s were

conduc ted

t o

de te rm ine whe the r t he AMK f u e l was s u f f i c i e n t l y pr oc e ss ed or

d e g r a d e d b e f o r e i n t r o d u c t i o n to t h e e ng i ne f u e l s ys te m. These f u e l c h a r a c t e r i -

z a t i o n

t e s t s

c o n s i s t e d o f f i l t e r r a t i o a nd t r a n s i t i o n v e l o c i t y m easurements

w hich p ro v id e d a c o r r e l a t i o n w i t h t h e f i l t e r s , f u e l n o z z l e s / i n j e c to r s ,

c om b us to r p e rf o rm a n c e, e t c . , p r e v i o u s l y e v a l u a t e d un d e r NASA C o n t r a c t

NAS3-22045 ( R e f .

1

)

.

I n Task 11, P r a t t

&

W hitn ey p a r t i c i p a t e d i n d e si g n re v i ew s and t e s t p l a n ni n g .

A

majo r bu t necessa ry gene ra l

e f f o r t was t h e a s s i s t a n c e r en d er e d t o

NASA

Ames-Dryden F l i g h t R ese arch F a c i l i t y i n t h e p l a n n i n g and i n s t a l l a t i o n o f b o t h

i n s t r u m e n t a t i o n and m o d i f i c a t i o n s

t o

t h e e n g i n e f u e l s ys te m f o r s t r u c t u r a l a n d

o p e r a t i o n a l c o n s i d e ra t i on s . T h is a c t i v i t y i n v o l v e d c o n s u l t a t i o n w i t h v e nd or s,

procurement of p r i n t s , s ch em at ic s and p a r t s , s e v er a l v i s i t s

t o

N A S A Ames-Dryden

F l i g h t Research F a c i l i t y and d i a lo g u e w i t h

NASA

Ames-Dryden F l i g h t Research

F a c i l i t y on a lm os t a d a i l y b a s i s .

T h i s r e p o r t d e s c r i b e s t h e b a s e l i n e JT3C-7 e n gi n e and i t s m o d i f i c a t i o n s

f o r

t h e

use o f AMK. T h e l e v e l s

o f

d e g r a d a t i o n a d e q u a t e f o r o p e r a b i l i t y i n t h e t e s t

a i r p l an e a re i d e n t i f i e d

f rom

f u e l c h a r a c t e r i z a t io n t e s t s . F i n a l l y , e ng in e

pe r fo rmance w i t h AMK d u r i n g t he se g ro un d and f l i g h t t e s t s

i s compared

t o

t h e

b a s e l i n e sea l e v e l p e r f or m a nc e e xp e c t ed w i t h J e t A .

EQUIPMENT

AND

PROCEDURES

T h i s

se c t i on des c r i b es t h e JT3C-7 eng ine and i t s components wh i ch wou ld be

a f f e c t e d

by

t he use

o f

a n t i m i s t i n g k ero se ne f u e l . I n a d d i t i o n , m o d i f i ca t i o n s

t o t h e b i l l - o f - m a t e r i a l e n gi n e f u e l s ys te m an d s p e c i a l t e s t e q ui pm e nt u se d

t o

a n a ly z e t h e a n t i m i s t i n g ke ro se n e w i l l

be d i scussed .

E N G I N E D E S C R I P T I O N

Four Pr a t t and Whi tney JT3C-7 eng ine s powered the C I D B-720-027(S/N 18066)

t e s t a i r p l a n e . The JT3C-7 e n g in e d e p i c t e d s c h e m a t i c a l l y i n F i g u r e

1

and

i l l u s t r a t e d i n d e t a i l i n Appendix A r e p r e s e n t s f i r s t - g e n e r a t i o n co mm ercia l

t r a n s p o r t t ec h n o lo g y . T h i s e n gi n e i s a d ua l- sp oo l, a x i a l - f l o w t u r b o j e t , w i t h a

16-stage compressor,

a c o - a nn u l a r c o m b u s ti o n s e c t i o n a nd a 3 - st a ge t u r b i n e . I n

t h e Bo ein g 7 20 a i rf r am e i n s t a l l a t i o n ,

t h e e n g in e i s 1 1. 4 f t l o n g ,

38 .9 i nches

i n d i ame te r and we ighs

3495 pounds. Key sp ec i f i c a t i o ns for t h i s e n gi ne a r e

shown i n Tab le I.

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TABLE

I

S P E C I F I C A T I O N S OF T HE JT3C-7 E N G I N E

T ak e- of f R a t in g ( a t sea l e v e l )

Maximum C o nt in u ou s R a t i n g ( a t s ea l e v e l )

Maximum S pe c i f i c Fue l Consumption

T o t a l

A i r f low

P r e s s u r e R a t i o

Dry

Weight

Engi ne Diamete r

Engine Length

12,000 l b . t h r u s t

10,000 l b . t h r u s t

.785 p p h l l b . t h r u s t

182 pps

13.0

3495 lbs .

38 .9 inches

11 .4

f t

Engine Fue l

S y s t e m

T h e p r i n c i p a l f u n c t i o n

o f

t h e a i r c r a f t f u e l system

i s

to s up p ly c l ea n l i q u i d

f u e l , f r e e

from

v ap o r, a t t h e r e q u i r e d p r e s s u r e s and r a t e s

o f

f l o w ,

t o

t h e

e n g i ne und er a l l o p e r a t i n g c o n d i t i o n s . F i g u r e 2 shows t h e b a s i c JT3C-7 f u e l

sys tem for a c om me rc ia l i n s t a l l a t i o n . F u e l

i s

s u p p l i e d f rom t he a i r c r a f t t an ks

t h r o u g h t h e n e c e s s a r y

f i l t e r s

a n d v a l v e s

t o

t h e e n g i n e - d r i v e n f u e l

pump which

i s a t wo -s ta ge , b y-p as s e q u i pp e d u n i t t h a t di s c h a r g e s f u e l

a t p r e de t e rm i n e d

p r e ss u r es and q u a n t i t i e s t h r o u g h a f u e l d e - i c i n g s ys te m ( c us t om e r o p t i o n a l )

t o

t h e f u e l c o n t r o l . T he f u e l d e - i c i n g f i l t e r a ss em bly c o n s i s t s o f a

40

m i c r o n

paper

f i l t e r

e le men t en cl os ed i n a c y l i n d r i c a l h ou si ng . A f t e r p r e s s u r i z a t i o n ,

t h e f u e l p a s s e s

t o

t h e f u e l c o n t r o l t h ro u gh a c oa rs e mesh i n l e t f i l t e r . The

f u e l c o n t r o l

i s

a h y d ro m e ch a n ic a l f u e l m e t e r i n g d e v ic e d e s i g n e d t o s c h e d u l e

t h e p r o p e r

f l o w o f

f u e l

t o

m a i n t a i n t h e e n g i n e s p e e d s e l e c t e d . T h e m e t e r e d

f u e l f lows t hro ug h th e a i r c r a f t f u e l - o i l

c o o l e r

t o

t h e p r e s s u r i z i n g a n d d u m p

v a l v e w h i c h s c h e d u l e s f l o w

t o

t h e f u e l n o z z l e s ec on da ry m a n i f o l d as a f u n c t i o n

o f p r i m a r y f u e l n o z z l e p r e s s u r e d r o p. T h i s e n su re s t h e p r o p e r f u e l s p r ay

q u a l i t y and d i s t r i b u t i o n

f o r

e f f i c i e n t c om b us ti on . The f u e l m a n i f o l d c o n s i s t s

o f e i g h t c i r c u l a r c l u s t e r s , each c l u s t e r h a v in g

s i x

d ua l o r i f i c e no z z l e s,

l o c a t e d i n t h e d i f f u s e r c ase a n nu lu s. The f u e l i s i n j e c t e d t h ro u g h each

c l u s t e r i n t o each

o f

e igh t combus t ion chambers where

i t m i x e s

w i t h a i r and

b u r n s .

Fuel Pump

-

The m a in f u e l pump ( F i g u r e 3 ) c o n s i s t s

o f

two p o s i t i v e d i s p l a c e m e n t

g e a r -t y p e p um pin g e le me nt s ( b o o s t s t a ge a n d m ai n s t a g e ) o p e r a t i n g i n s e r i e s t o

s u p p l y f u e l

t o

t h e e ng in e f u e l c o n t r o l . Power t o d r i v e t h e pump i s s u pp l ed

d i r e c t l y by t h e m ain d r i v e s h a f t . U nder no rm al o p e r a t i n g c o n d i t i o n s , f u e l f l ows

t h r o u g h

t h e

pump

f rom

t h e f u e l i n p o r t t o t h e i n l e t f u e l f i l t e r e lem e n t

c o n t a i n i n g a

s e l f - r e l i e v i n g v a l v e to t h e b o o s t s t a g e . B et we en t h e b o o s t a n d

m ain stage i s t h e i n t e r s t a g e 40 m i c ro n p l e a t e d p ap er f i l t e r and o p t i o n a l

de- icer sys tem.

The bo o st s t ag e p r e s s u r e r e g u l a t i n g v a l v e c o n t r o l s t h e p r e s s u r e

o f

t h e f u e l d e l i v e r e d

to

t h e m a i n s ta g e i n l e t a t b et we en 45 a nd 65 p s i a b ov e

pump i n l e t pr e s s u r e . The r a t e d c a p a c i t y of th e pump i s 41.6 gpm a t 3260 rpm

and a d i scharge p ressu re

o f

1 0 0 0 p s i g .

Fue l Con t ro l

-

The H a m i l t o n S t a n d a r d JFC25-10 f u e l c o n t r o l ( F i g u r e 4 )

i s

a

h y dr o me c ha n ic a l h i g h c a p a c i t y f u e l

f low

m e t e r i n g u n i t d es ig ne d

to

p e r m i t

s e l e c t i o n o f t he d e s i r e d e ng in e t h r u s t l e v e l t hr ou gh ou t t h e f l i g h t en ve lo pe

o f

4

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QUALITY

T H I S P A S S A O C

L O C K C D

WNEU

O C T I W A L C U L

H L A l L R

USED-

ENGINE WCCLICD

A I R r R A U C

SUPPLIED

FUEL-OIL COOLER

OPTIONAL EQUIP

OPTIONAL

---

C W l P Y C M l 1

I

IR CONTROL

VALYC

a

I I I

I ' I

OVCRBOARO

I

i

r

C YC R G C U C V

CUCL

SHUT-WC

VALVES

L

Figure

2 B a s i c

JT3C-7 Fuel System

5


10/48

PUMP INLET PRESSURE

I 1 UMP

BOOST

PRESSURE

-

UMP OUTLET PRESSURE

MAIN DRAIN

F i g u r e

3

Two-Stage

Main

Fuel Pump

6

ORIGINAL

PAGE

IS

OF

POOR QUALITY


11/48

ORIGIN L PAGE

IS

O POOR QUALITY


12/48

t he J T3C- 7 e ng i ne equi pped ai r c ra f t . Two manua l l y ope ra t e d l e ve rs a r e pr ovi ded

on each cont r ol : a power l ever f or r egul a t i ng e ng i ne t hr us t i n t he r ange f r om

ful l

r ever se t hr ough i dl e

t o

t akeof f ; t he o t h er , a shut o f f l ever t o r egul at e

f uel f o r engi ne s t a r t i ng and shut down. The var i abl e s se nse d

by

t he f uel c ont r ol

ar e power l ever ang l e , bur ner pr essur e and engi ne

N Z

r ot or s peed. By ut i l i z -

i ng t hes e v ar i a bl es , t he f uel c ont r ol a c c ur a t e l y go ve r n s t he engi ne s t ea dy

s t a t e s el ec t ed s peed and l i m t s f uel f l o w f or a cc el er at i o n and dec el er a t i o n

t hr ough a speed- governi ng sys t em of t he pr opor t i onal o r dr o op t y pe.

.

f

T

The f uel cont r ol may be cons i dered as cons i s t i ng of a f uel - met er i ng s y s t em and

a comput i ng syst em

The met e r i ng sys t e m r e gul a t es t he f uel suppl i e d t o t he

f uel c ont r o l

by

t he eng i ne dr i ven f uel pump t o prov i de t he eng i ne t h rust

out put demanded by t he p i l ot , but s ubj ec t t o engi ne oper at i ng l i m t at i ons as

sensed and schedul ed by t he f uel cont r ol comput i ng sys t em The comput i ng sys t em

senses and combi nes var i ous oper at i ona l par amet er s t o gover n t he out put of t he

met er i ng syst em

of

t he f uel c ont r ol dur i ng al l e ngi ne o pe r a t i ng r egi mes .

F i gur e

5

i ndi cat es t he f uel cont r o l pa ramet er s

and

schedul i ng accur acy

r equi r ement s f or t hese par amet er s .

'2.5

SPEED GOVERNOR

DECELERATION SCHEDULEI

T

~~ ~ ~

ENGINE HIGH

ROTOR

SPEED, N2 RPM

F i gur e

5

J T3C 7

Fuel Cont r o l Schedu l i ng Accur acy Requi r ement s

8


13/48

f i l

i

ng

f

ue

The

J T3C 7

combus t o r sec t i on cons i s t s

of

ei ght separ at e t ubu l ar combust i on

chamber s i n

a

co- annul ar a r r angement . The chamber s , as v i ewed f r om t he r ear

of

t he e ngi ne ,

ar e number ed c l ockwi se st art i ng wi t h t he upper most chamber as No.

1 .

These chamber s ar e i nt er connect ed by cross - over t ubes f o r f l ame pr opagat i on

dur i ng s t a r t i ng.

L i ght i ng o r s t ar t i ng i s i ni t i at ed f r om s par k i gni t er s l ocat e d

i n t he No.

4

and

No.

5 combust i on chamber s. Each combust i on chamber compr i ses

a s er i es

o f

f or med sheet - met al , ai r c ool ed c yl i ndr i c al l i ner s .

The f or t y- ei ght f uel

nozz l e assembl i es ar e suppor t ed i n t he f uel mani f o l d and

a r e a r r anged i n ei ght c l us t er s

of

s i x noz zl es eac h. Eac h c l us t e r pr oj ec t s i nt o

accommodat i ng aper t ur es i n t he upst r eam e n d o r dome of each combust i on

chamber . The

J T3C 7

combus t o r empl oys a dual - or i f i ce pr essure a t om z i ng f uel

F i l t er Sy st ems

-

The J T3C- 7 engi ne

f uel

s y s t e m i nc or por at es s ev er al f uel

t er s di f f er i ng i n c ons t r uc t i on, f i l t e r ar e a and f i l t r at i on qual i t y depend-

on t he subsys t em component pr o tec t i on r equi r ement s . Tab l e I 1 pr ovi des

a

s y s t e m f i l t er t abul at i on f or t he J T3C- 7 engi ne. I t s h oul d be not ed t h e

i nt er s t age

40

m c r o n pl eat ed paper f i l t er p r o vi des t he pr i mar y pr ot ec t i on f o r

al l s ubs y s t e m c omponent s . I t a l s o ac t s as a c ol l ec t o r of f uel bor ne i c e

c r ys t a l s . An opt i ona l f uel de i c i ng sys t emcan be added t o t he engi ne t o

i nc r eas e f uel f i l t er i nl et t emper a t ur e s, c l ear i ng t he f i l t er of c ol l ec t e d i c e

TABLE I 1

J T3C 7 FUEL SYSTEM FI LT ER SURVEY

Component

Loca t

i on

Mat er i al

Por e Si ze Ar ea (in)

Fuel Pump I nl et St ai nl es s St eel 400 m c r o ns

5. 15

Fuel Cont r ol I nl et St ai nl es s St eel

200

m c r o ns

18. 8

Fuel Cont r ol S er v o St ai nl e s s St e el 40 m c r o ns 7. 1

P r e s s ur e and I nl e t St ai nl e s s St e el 74 m c r o ns 8. 5

Dump Val ve

Fuel Nozzl e Pr mar y

St ai nl es s St eel

007

-

.009

Di a.

0. 39

Fuel Nozzl e Secondar y

St ai nl es s St eel

007

-

.009

Di a.

0. 47

openi ng

openi ng

*Repl aced for CI D Tes t - See Engi ne Modi f i cat i ons f o r AMK Sect i on

Combust or Descr i pt i on

9


14/48

n o z z l e ( F i g u r e 6)

to o b t a i n t h e r e q u i re d turndown r a t i o ( r a t i o o f maximum to

min imum fue l f l o w ) . The nozz les a re des igned

t o

d i s c h a r g e a p r e d e t e r m i ne d

amount

o f

f u e l when s p e c i f i e d p r e s s u r e d r op s a r e m a i n t a i n e d a cr o s s t h e p r i m a r y

and secondary s tages,

a c t i n g b o t h as an a t o m i z i n g an d m e t e r i n g d e v i c e . The

r e l a t i o n s h i p betw een f u e l

f low

a n d n o z z l e p r e s s u r e d r o p

for

a t yp ica l JT3C-7

e n g i n e

i s

shown i n F i g u r e

7 .

The p r es su r i z in g and dump va lv e i s used

t o

channe l f l ow t o t h e p r im a r y

or

secondary

sys tem.

When the secondary c rack ing

or

s t a g in g p o i n t

i s

reached , th e secondary va lv e opens and

f l o w i s

a d m i t t e d t o

t h e s ec on da ry s y st e m. U n t i l t h e n t h e s y s te m

f l o w

i s

t o

t h e p r i m a r y o n l y . T h i s

s t a g i n g p o i n t

i s

c o n t r o l l e d b y a s p r i n g l o ad e d v a l v e , w h ic h i s s e n s i t i v e t o

t h e d i f f e r e n c e b et we en

f u e l

p r es su re and combus to r p ress u re .

1. SPRING

6.

PRIMARY STRAINER 11. NOZZ LE BOD Y INSERT

2. 1OWERPR)MARY FERRULE

7. S P R I N G S EA T S N A P R I N G 1 2 . P R IM A R Y

PLUG

3.

UPPER PRIMARY FERRULE

8. I N N E R S E C OND A R Y S TR A IN E R S N A P R I N G 1 3. N OZZL E B OD Y

4. SPRING SEAT

9

OU TE R S E C ON D A R Y S TR A IN E R S N A P R I N G

14.

I N S E R T S N A P R I N G

5.

PRIMARY STRAINER SNA PR ING 10. SECONDAR Y STRAINER

1 5 . R E T A I N I N G N U T

F i g u r e

6

Fue l Nozz le

E N G I N E M O D I F I C A T I O N S F O R A M K

8-720

F l i g h t

T e s t

Engines

The approach fohlowed by the

F A A

has been

t o

b l e n d J e t A and FM-9 ad d i t i v e

i n - l i n e a t th e a i r c r a f t f u e l i n g p o i n t

t o

produce an

AMK

f u e l w i t h a c ce p ta b le

f i r e s up re ss io n p r o p e r t i e s i n th e a i r c r a f t ' s f u e l t an ks . T h is ap pr oa ch r e q u i r e s

t h a t t h e

AMK

be a c c e p t a b l e and us e ab l e w i t h i n t h e a i r c r a f t ' s f u e l and e n gi ne

s y st e m s. C o m p a t a b i l i t y s t u d i e s

( R e f s . 1,4 ,5 ,6>

e v a lu a t in g t h e e f f e c t s

of

u s i n g

AMK

o n

the per formance

o f

a i r f r am e fue l sys tems and eng ine components showed

10


15/48

1.000

1o.ooo

NOZZLE PRESSURE DROP, PSlD

(FUEL PRESSURE-BURNER PRESSURE)

F ig u re 7 JT3C-7 Fuel

Flow

Schedu le

t h a t t h e

AMK

needed

t o

be processed

or

degraded

t o

a f u e l s u i t a b l e

t o

meet t he

r e q u i r e m e n t s o f t h e JT3C-7 eng ine s f o r th e 8-720 a i r c r a f t for t h e p l a n n e d

F u l l - s c a l e T r a n s p o r t C o n t r o l l e d I m pa c t De m on s tr at io n ( C I D ) t e s t . S p e c i f i c a l l y ,

t h e s e r e q u i r e m e n t s

i n v o lv e d e ng in e o p e r a b i l i t y ( s t a r t i n g , a c c e l e ra t i o n /

d e c e l e r a t i o n , r e l i g h t ) a nd p er fo rm a nc e ( e f f i c i e n c i e s ,

e x i t

t empera tu re

d i s t r i b u t i o n , f i l t e r a b i l i t y ) .

S e v e ra l s t u d i e s n t h e U n i t e d S t a t e s and U n i t e d K in gdo m i n d i c a t e d t h a t t h e

FM-9 po lymer can be h i g h l y degraded and t h e AMK r e s t o r e d to n e a r J e t A

p r o p e r t i e s ( R e f s 1 ,2 ,3 ).

A

p r o t o t y p e

AMK

f u e l d e g r a d e r

for

t h e

C I D

a i r c r a f t

was deve loped by t h e Gene ra l E l e c t r i c Company based on a h i g h speed , a i r

d r i ve n c e n t r i f u g 1 pump. F o ur d e g ra d e r s o f t h i s t y p e , n e c e s s a r y for t he 8720 ,

were to be eng ine n a c e l l e mounted and capab le

o f

r u n n i n g o n J e t

A

and /o r

degraded AMK for t h e r e q u i r e d g ro un d and f l i g h t t e s t m i s s i o n s.

NASA

Ames-Dryden F l i g h t R es ea rc h F a c i l i t y was r e s p o n s i b l e

f o r

t he i n s t a l l a t i o n

o f

t h e f o u r d e g r a de r s ys te ms o n t h e 8 720 a i r c r a f t as

w e l l as necessary

m o d i f i c a t i o n s t o t he a i r c r a f t .

F i g u r e 8

i s

a schemat ic

of

t h e

AMK

d eg ra de r s ys te m i n s t a l l e d

f o u r e n g i n e s

o f the 8-720

C I D

a i r c r a f t .

Th e

p r i m a r y d e g ra d e r

c o n s i s t e d of t h e

F l O l

eng ine augmentor ce n t r i f u ga l pump, t he

a u x i l i a r y power a i r t u r b i n e m ot or , and f u e l p r e ss u r e t h r o t t l

11

on each o f t h e

components

C5A a i r c r a f t

n g v a l v e . The a i r


16/48

8 7 2 0 A MK I N S T A L L A T I O N PA RT S L I S 1

I T E M

40

4 1

4 2

4 3

4 4

4 5

50

5 1

5 2

53

54

5 5

5 7

58

5 9

6 2

6 3

6 4

65

66

6 7

68

69

7 0

7 1

7 2

7 3

7 4

7 5

7 6

7 7

7 8

7 9

8 2

8 3

8 4

85

86

0 7

88

89

90

9 1

9 2

9 3

94

9 5

96

9 7

98

99

1 0 0

1 0 1

1 0 2

1 0 3

1 0 4

105

1 0 6

1 0 7

1 0 8

1 0 9

1 1 0

1 1 1

1 1 2

1 1 3

1 1 4

D ESC R I PTI O N

DEGRADER SPEED CONTROL FUEL FLOW SENSOR

DEGRADER ASSEMBLY. PUMP AND A I R TU RBINE MOTOR (AT M)

DEGRADER MOUNTING BRACKET

FUEL LIN E ADAPTER ( INCLUDE S TWO - 4 N I P P L E S )

FUEL HOSE. 3 00 0 P S I OPERATING (0. 75 - IN CH NOM)

FUEL TUBE, 10 00 P S I OPERATING (0. 75 - IN CH NOM)

FLO W O R I F I C E ( 0 . 75

-

0. 50 INCH MS REDUCER)

FUEL RECIRCULA TION HOSE, 10 00 P S I OPERATING (0. 75 - IN CH NOM)

FUEL/AIR HEAT EXCHANGER

HEAT EXCHANGER MOUNTING BRACKET

HEAT EXCHANGER AI R FLANGE CLAMPS

HEAT EXCHANGER AI R DUCT

BELLMOUTH AI R SCOOP

FAN AND RELAY (1 1 5 VAC, 3 PH, 4 00 HZ, 11 A, INRUSH 90 A/PH

FAN MOUNTING BRACKET

QTY/

ENGINE

1

1

1

2

1

1

1

1

1

1

2

1

1

FOR 1 SEC) 1

1

FAN WIRING AN0 CIRCUIT BREAKER

ATM OI L COOLER

ATM O I L COOLER MOUNTING BRACKET

ATM O I L HO SE, 100 0 P S I OPERATING (0. 50 - IN CH NOM)

A T M O I L F I L T E R

ATM OI L F IL TE R MOUNTING BRACKET

ATM O I L PUMP ( 2 8 VOC.

22

A, INRUSH 135 A FOR 0 .5 SEC)

ATM O I L PUMP BYPASS FLOW ORI FI CE ( 0. 50 - IN CH NOM)

ATM OI L PUMP MOUNTING BRACKET WI RING AN 0 RELAY

ATM O IL PRE SSURIZA TION HOSE (0.25- I NCH NOM)

ATM SEAL DRAI N HOSE (0. 37 5- INC H NOM)

FUEL THROTTLING VALVE

FUEL THROTT LING VALV E MOUNTING BRACKET

COP A IR BLEED REG CHK AND

S / O

VALVE WI TH C LAM PS ( C V880)

ENGINE FUEL SUPPLY HOSE, 1 00 0

P S I

OPERATING (1.5 - INCH NOM)

FU EL BYPASS VALVE ( 1 . 5 - I N C H , 14 / 2 8 VDC . 1 A )

FUEL BYPASS VA VE MOUNTING BRACKET

ATM SPEED SIGNAL CABLE AN0 CONNECTORS

ATM AI R SU PPLY DU CT ( 3 . 5 - I N C H N OM, 0 . 04 0 WALL STAI N LESS STEEL)

ATM AI R REGULATOR AND SHUTOFF VALVE CLAMPS

ATM A I R REGULATOR AN0 SHUTOFF VALVE ( 2 8 VDC. 1 A

ATM AIR SHUTOFF VALVE AND ATM AIR INLET CLAMPS

C DP AI R BLEED t A LV E SWI TCH ( C O C KPI T)

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

3

ATM AI R SHUTOFF VALVE ( 2 8 VOC. 1 A ) 1

ATM A IR EXHAUST OUCT CLAMP 1

ATM A IR EXHAUST OUCT (4.0 - INCH NOM, 0. 02 0 WALL STAINL ESS STEE L) 1

FUEL THROTTLING VALVE SERVO PRESS. TUBE. 300 0 PS I OPERATING (0 .25 - IN . ) 1

FUEL HEATER JUMPER TUBE 1

SIGNAL CONVERTER (FUEL SENSOR SIGNAL TO VDC) 1

ATM O I L PRESSUR E ( 0 - 2 00 PSI G ) 1

DEGRADER FUEL DISCHARGE PRESSURE (0 -2 00 0 PS IG) 1

DEGRADER FUEL DISCHARGE TEMPERATURE (O o- 25 O0 F) 1

THROTTLING VALVE INTERSTAGE PRESSURE (0- ?5 0 PSIG) 1

FAU LT CONVERTER (SENSOR SIGNA L TO VOC) 6

ENGINE FUEL PUMP INLET PRESSURE (0-150

P S I G )

1

PRIMARY FUEL NOZZLE PRESSURE (0-1000

P S I G )

1

SECONDARY FUEL NOZZLE PRESSURE (0 -1 00 0 P S I G ) 1

EN G IN E FU EL F I LT ER D I FFER EN T I AL PRESSU RE ( 0 - 5 0 PSI O ) 1

DEGRADER FUEL INL ET TEMPERATURE (0 " - 17 5" F) 1

DEGRADER FUEL INL ET PRESSURE (0 -50 PS IG) 1

ENGINE FUEL PUMP INLET TEMPERATURE

( 0 " - 2 0 0 " F )

1

ENGINE SCAVENGE O I L TEMPERATURE (O0 -35O "F) 1

ATM O I L TEMPERATU RE ( 0 - 300 " F) 1

FUEL CONTROL WASH SCREEN DIF FE RE NTI AL PRESSURE ( 0- 50

P S I O )

1

THROTTL ING VALVE LEAKAGE CHECK VALVE 1

THROTTLING VALVE LEAKAGE HOSE, 1000

P S I

O PER ATI N G ( 0 . 50- I N C H ) 1

CHECK VALVE 1

PRESSURE TRANSDUCER. 50 P S I 0 MFP INLET-MF P INL ET SCREEN ENG

2 3

DIFFERENTIAL PRESSURE TRANSDUCER

RESTRAINED BELLOWS

ATM AI R SUPPLY DUCT ( 3 . 5 NOM,

0 .040

WALL WITH 2- . 3- INCH BELLOWS)

SU PPLI ED

BY

NASA

NASA

NASA

NASA

GE

GE

NASA

GE

NASA

GE

NASA

GE

GE

NASA

GE

GE

NASA

GE

GE

NASA

GE

NASA

NASA

GE

GE

GE

NASA

GE

GE

GE

GE

GE

NASA

NASA

GE

NASA

NASA

NASA

NASA

NASA

GE

GE

GE

GE

GE

GE

GE

GE

GE

GE

GE

GE

GE

GE

GE

GE

GE

GE

GE

NASA

GE

GE

COCKFIT

( A > D E G R AD E R P A R T S

Figure

8 8720

Anti-Misting Kerosene Degrader Installation Schematic

ORIGINAL PAGE IS

OF POOR QUALITY

12


17/48

ORIGINAL PAGE Is

OF POOR

QUALnvl

8EEcQo w

NOZZLE8

( B > D E G R A D E R S C H E MA T I C

F i g u r e

8

8720

A n t i - M i s t i n g K er os en e D egrader I n s t a l l a t i o n Sc he m at ic ( C o n t ' d )

13


18/48

ORIGIN L P GE S

OF POOR QU LITY


19/48

ORIGIN L

P GE

IS

OF

POOR QU LITY

a

n

K

7

.

5


20/48

ORIGIN L P GE S

OF POOR QU LITY


21/48

t u r b i n e w as d r i v e n b y co mp re ss or b l e e d a i r d u r i n g e n g i n e o p e r a t i o n a nd was

capab le

o f

p r o v i d i n g d eg ra de d AMK

for

e ng in e s t a r t t h r o u g h t h e u se o f h i g h

p re ss ur e a i r f rom g r o u n d c a r t s or eng ine c ross b l ee d . The

F l O l

engine pump

u t i l i z e d b y

G . E .

as the degrader had a des ign

f low

c a p a c i t y much h i g h e r t h a n

t h a t r e q u i r e d

b y

th e JT3C-7 eng in e . There fore , i t was necessary t o i n c l u d e a

r e c i r c u l a t i o n l o o p t h r ou g h an a i r - f u e l h ea t e x ch a ng e r, m ou nte d i n a n e x t e r n a l

wing mounted pod, to d i s s i p a t e e x ce ss h e a t g e n e r a t e d b y t h e d e g r a d e r t o t h e

f u e l .

A

t h r o t t l i n g v a l v e l o c a te d a t t h e degrader e x i t r ed uc es t h e f u e l

p r e s s u r e b e f o r e t h e m a in f u e l e n g i n e pump

to

a c c e p t a b l e l e v e l s

(


22/48

I n p r ep a ra t io n for o n e s e r i e s of t e s t s c on du ct ed a t t h e F A A T e c h n i c a l C e n t e r ,

t h e JT3C-6 f u e l c o n t r o l was m o d i f i e d b y b l o c k i n g s h u t t h e s e r v o f i l t e r bypass

and r e p l a c i n g t h e 74 m i c r o n i n l e t f i l t e r s c re e n w i t h a n ew l y f a b r i c a t e d 2 00

m ic ro n s iz e f i l t e r . A t t h e r e q u e s t of

N A S A I F A A ,

a n o t h e r s e r i e s o f t e s t s w e r e

schedu led to e v a l u a t e th e o p e r a b i l i t y

of

t h e JT3C-7 co n t ro l

o f

t h e B-720 t e s t

a i r p l a n e when o p e r a t i n g o n AMK f u e l .

P r a t t & W hi tn ey a s s i s t e d i n t h e

p r e p a r a t i o n a nd

i n s t a l l a t i o n of a JT3C-7 fu e l c on t r o l on th e JT3C-6 eng ine .

The JT3C-7 f u e l co n t ro l was i nsp ec t ed , r e pa i r ed and m od i f i ed w i t h a down

c ha nge a c c e l e r a t i o n cam i n o r d e r to m a k e t h e c o n t r o l

c o m pa t ib l e w i t h t h e

JT3C-6 t e s t e n g i n e . I n s t a l l a t i o n of the cam and checkout was accompl ished by

Hami l t on S tanda rd . A mockup of t h e JT3C-7 c o n t r o l a nd s e v e r a l s p e c i a l f i t t i n g s

were prov ided

to

a s s i s t i n p l um b i ng t h e m o d i f i e d JT3C-7 f u e l c o n t r o l to t h e

JT3C-6 eng ine . The re s u l t i n g schedu le

i s

shown i n F i g u r e 1 2 w i t h t h e B i l l - o f -

M a t e r ia l JT3C-6 and JT3C-7 sch edu les.

CONTROL SPEED - Nc, RPM

x l o

F i g u r e 12 F u e l C o n t r o l A c c e l e r a t i o n S c h ed u le s

18


23/48

UNDEGRADED

104,

A M K

,

-

5 81

I I

I I I 1 1 1 1 1 1 I I11111 I I 1 1 1 1 1 1 1 I

I

l l l W

C

106

1 0 5

CONDITIONS

m O A

PUMPSPEED IRPMI 2400 3000 3000

FUEL

FLOW

(kg/hr) 750 1590 1590

DISCHARGE PRESSURE IkPa) 207 0 3450 345 0

- \

3.6

1.6

1.4 1.2 1.2

- A . .

m

I V

I

i I

1

i f i I I

1 2 4 5

6

7

8

9 1 0 11 12 13 14 1 5 1 6

NUMBER OF PASSES THROUGH J T ID FUEL PUMP

F i g u r e

13

Fi l te r R a t i o S en s i t i v i t y

Undegraded AMK Degraded AMK

E

Transition

velocity

E

0.01 0.1 1 o 10 100

Velocity

approaching

f i l ter, cm /sec

F i g u r e 1 4

T r a n s i t io n V e l o c i t y

19


24/48

LABORATORY FLOW C H A R A C T E R I Z A T I O N E Q U I P M E N T

Under N A S A / F A A sponso rsh ip ,

P r a t t & W h it ne y i n v e s t i g a t e d t h e e x t e n t o f

AMK

p r e - s h e a r i n g or d e g r a d a t i o n r e q u i r e d t o e na bl e s a t i s f a c t o r y o p e r a t i o n of t h e

e n g in e com ponents a t v a r i o u s f u e l t e m p e ra t u re s . F u e l c h a r a c t e r i z a t i o n t e s t s ,

d e v e l o p e d b y P r a t t & W h it ne y an d o t h e r i n v e s t i g a t o r s , w er e u se d to de te rm ine a

c o r r e l a t i o n w i t h t h e pe rfo rm an ce r e q u i r e d

o f

t h e f i l t e r s , f u e l n o z z l e s a nd

combustor o f th e JT3C-7 eng ine for t h e C I D m i s s i o n . Because t h e a n t i m i s t i n g

a d d i t i v e i nc re as es t h e e f f e c t i v e v i s c o s i t y o f t h e b l e n d e d AMK f u e l , t e c h n i q u e s

t h a t measured v i s c o s i t y a nd f i l t e r a b i l i t y were u sed t o q u a n t i f y t h e e x t e n t t o

which

AMK

was degra ded fr o m i t s i n i t i a l o r i g i n o r unshea red s t a te .

For

low

l e v e l s o f p ol ym e r d e g r a d a t i o n , t h e d e g r a d a t i o n l e v e l was e v a l u a t e d b y a f i l t e r

r a t i o o b t a i ne d f rom a s i n g l e f l o w f i l t r a t i o n t e s t . T hi s t e s t

i s

a r a t i o o f t h e

t i m e s

r e q u i r e d

f o r

a k n o w n q u a n t i t y of t e s t f u e l and t h e same q u a n t i t y

o f J e t

A

f u e l

t o

f l o w t hr ou g h a s p e c i f i e d f i l t e r (1 7 m i c ro n sc re en ) ( s e e Appendix 6-1

f o r a d e t a i l e d p r oc e du r e) .

I n an e a r l i e r p ro gra m

( R e f .

1 > , AMK was degraded by in c re a s in g number

o f

passes t h rough a JT8D fue l pump . The sens i t i v i t y o f f i l t e r r a t i o t o the number

of

passes through the pump

i s

shown i n F i g u r e 1 3 . T h i s p l o t an d su b se qu e nt

t e s t s

showed t h a t a l t ho ug h f i l t e r r a t i o i s an adequate measurement techn ique

f o r

d e g r a d a t i o n l e v e l s e q u i v a l e n t

t o f i l t e r

r a t i o s d o w n t o a p p r o x i m a t e l y two,

i t d i d n o t p ro v i de s u f f i c i e n t r e s o l u t i o n t o d e s c r ib e l e v e l s b elo w t h a t p o i n t .

F i l t e r a b i l i t y , f u e l s pr ay q u a l i t y , and c om bu st io n t e s t s r ec or de d i n R e f. 1

i n d i c a t e d t h a t t h e r e w e r e s i g n i f i c a n t d i f f e re n c e s i n t h e way AMK deg raded

between the

3

and 16 passes per fo rmed a l though

f i l t e r

r a t i o s showed a l m o s t n o

d i s t i n c t i o n .

I n f i l t r a t i o n e xp er im en ts , when

AMK

v o l u m e t r i c f l o w r a t e p er u n i t

a rea or v e l o c i t y i s p l o t t e d a g a i n s t i n c r e a s i n g d i f f e r e n t i a l p r e ss u r e a cr os s a

v er y f i n e f i l t e r , t h e r e

i s

a n o t i c e a b l e i n cr e a se i n f l o w r e s is t a n ce a t a

p a r t i c u l a r v e l o c i t y a s shown i n F ig u r e 14. The s h i f t p o i n t

i s

a f u n c t i o n

o f

f u e l t y pe o r l e v e l o f AMK d e g r a d a t io n and has been l a b e l e d t r a n s i t i o n v e l o c i

( V , ) .

I t has been hypo thes i zed t ha t t hese

s h i f t s

or

t r a n s i t i o n v e l o c i t i e s

are analogous t o t r a n s i t i o n

from

l a m i n a r t o t u r b u l e n t f l o w w i t h i n t h e

f i l t e r

P r a t t & Whi tney has found t h i s measurement tech n iqu e t o be a va luab le and

rep rod uc ib l e means o f c a t e g o r i z i n g h i g h l y d eg ra de d AMK f u e l s .

A

d e t a i l e d

l a b o r a t o r y p r o c e du r e

f o r

m ea su rin g t r a n s i t i o n v e l o c i t y

i s

i n c l u d e d i n A ppend

6-2.

T h e l e v e l s

of AMK

deg rad a t i o n recommended by P r a t t & Whi tney

t o

s a t i s f y t h e

f i l t e r a b i l i t y and combus to r pe r f o rmance re qu i r e d

for

t h e C I D program

w i l l

be

assessed

i n

t h e n e x t s e c t i o n of t h i s r e p o r t .

RESULTS AND D I S C U S S I O N

FUEL

SYSTEM

AND E N G I N E OPERABILITY

P r a t t

&

Whi tney ass i s t ed

N A S A

i n d e t e rm i n i n g th e s a f e t y and m i s s i o n s u i t -

a b i l i t y o f t h e m od i f ie d f u e l

s y s t e m

f o r t h e p r o p o s e d e n g i n e t e s t s a n d

s ub se qu en t f l i g h t s . T h i s s t u d y re v i ew e d an d a n a l yz e d i n f o r m a t i o n and t e s t d a t a

r e c e i v e d from

N A S A / F A A

r e g a r d i n g t h e d e g r a d e r s y st em , h e a t e x c ha n g e rs , e n g i n e

fu e l sys tem and subsequent e f f e c t s t o eng ine o i l a n d f u e l a s t h e y p e r t a i n e d t o

operab i l i t y . Recommended l i m i t s f o r f u e l d e g r a d a t io n and e ng in e c o n d i t i o n

( 5 )

were de termined and presented t o

N A S A / F A A .

20


25/48

The f i 1 e r a b i

1

i y c h a r a c t e r i s t i c s of a l l t he f u e l

system components were

su rveyed t o a s s e s s c l o g g i n g for s u b s e q u e n t e n g i n e t e s t s .

A summary o f t h e

J T 3 C - 7 b i l l - o f - m a t e r i a l f u e l s y s t e m f i l t e r s and s c re en s i s t a b u l a t e d i n T ab le

11. These f i l t e r s w ere i n c l u d e d i n t h e as se ssm en t e x c e p t fo r t h e f u e l p u m p

i n t e r s t a g e w h i c h was r e p l a c e d by a

G E

5-79 metal f i l t e r o f s m a l l e r a r e a b u t

s l i g h t l y c oa r se r mesh s i z e

( 4 4 m i c r o n s ) . Based o n known f i l t e r c h a r a c t e r i s t i c s

( a r e a , m esh s i z e , f u e l flow r eq ui re m en ts ) and t h e f i l t e r a b i l i t y e x p er im e nt s

per fo rmed under

NASA

c o n t r a c t NAS3-22045 and documented i n

R e f .

1 , t h e

pressure and dump ( P & D ) , a n d f u e l

c o n t r o l s er vo f i l t e r s were ju dg e d t o be

most

s u s c e p t i b l e t o cl og g in g . The c l og g in g phenomena due t o g e l f o r m a t i o n was f o u n d

t o

b e a f u n c t i o n

of

i n c re a s e d f u e l

flow

o r v e l o c i t y , d ec re as ed f u e l t e m pe r at u re

a n d c u m u l a t i v e

t i m e

(Ref. 1 ) . T h e r e f o r e , i t was p r o j e c t e d t h a t f o r s h o r t

d u r a t i o n s , low a l t i t u d e f l i g h t s and e nv ir on me nt al c o n d i t i o n s f o r t h e

C I D

program, AMK degraded t o f i l t e r r a t i o s o f a p p r o x i m a t e l y 1 . 2 or t r a n s i t i o n

v e l o c i t i e s a t l e a s t 2-3 cm /sec.,

w ou ld pr e cl u de c l o g g i n g i n t h e e n gi n e f u e l

system. Based on f u e l no zz le sp ray q u a l i t y and subsequen t combus t i on t e s t s

( R e f .

1 > ,

t h i s l e v e l

o f

de gr ad at io n was judged

t o

b e a c c e p t a b l e

for

e n g i n e

c om bu st or r e q u i r e m e nt s as w e l l . I n a d d i t i o n , t h e e n g i n e two stage gear pump

c o u ld p r o v i d e f u r t h e r d e g ra d a t i o n m ar gi n t o t h e AMK f u e l

d e l i v e r e d from t h e

d e g r a d e r s ys te m. I n

t h e ev en t t h a t s i g n i f i c a n t c l o g g i n g o f t h e se r v o f i l t e r

ta ke s p la c e , t h e f u e l c o n t r o l c o ul d be g in t o r e a c t s l u g g i s h l y , e s p e c i a l l y a t

low power . Comp le te b l ock i ng o f t h e s e r vo f i l t e r w o ul d c au se

loss

o f s e r v o

p r e s s u r e w i t h s ub se qu en t f u e l

flow

r e d u c t i o n

t o

a min imum set t ing . The min imum

flow l e v e l

for

th e JT3C-7 eng ine i s 640 pph which i s be low i d l e . Remova l of

t h e s e r v o

f i l t e r

was n o t p r a c t i c a l b eca use c o n ta m i na n t s c o u l d a f f e c t t h e

v a r i o u s s e rv os r e s u l t i n g i n u n p r e d i c ta b l e m e t e r i n g and g o v e rn i n g e f f e c t s . For

r easons

o f

s a f e t y ,

i t

was s t r o n g l y recommended t h a t f i l t e r s l s c r e e n s w i t h o u t

p r o v i s i o n s for a u t o m a ti c b yp as s, ( f u e l c o n t r o l s e r v o a nd f u e l n o z z l e s ) be

m o n it o re d on a l l f o u r e n g i n e s

for

p r e s s u r e r i s e .

I t

was a l s o recommended th a t

a p p r o p r i a t e f u e l samples be a na ly ze d f o r d e g ra d at io n l e v e l b y f i l t e r r a t i o and

t r a n s i t i o n v e l o c i t y t e s t s .

I n f o r m a t i o n was s u b m i t t e d

to

NASA Ames-Dryden F l i g h t R es ea rc h F a c i l i t y i n t h e

areas o f e n g in e and com ponent o p e r a b i l i t y and d u r a b i l i t y , a i r b l e e d , p lu m b in g ,

i n s t r u m e n t a t i o n , e t c . T h i s s e c t i o n summarizes o n l y t h e more c r i t i c a l a re a s

t h a t r e qu i r e d s i g n i f i c a n t s tu dy or ana l ys i s . One o f t h e f i r s t a reas o f

i n v e s t i g a t i o n con cern ed t h e a v a i l a b i l i t y and e f f e c t s

of

e ng in e b le e d a i r

r e q u i r e d t o d r i v e t h e a i r t u r b in e motor d r i v e f o r t h e d e g r a d e r . A i r b l e e d

f l o w s a nd p re s s u r e l e v e l s p r e d i c t e d

for

d e g r a d e r o p e r a t i o n

(G.E.

computer

model) were compared

t o

t hose av a i l a b l e fr om th e JT3C-7 eng ine . Tab le

I11

shows t h e r e s u l t s

o f

t h i s c om pa rison w hic h i n d i c a t e s t h a t t h e a i r b l e e d

r eq ui re m en ts were o n l y s l i g h t l y h i g h e r t ha n t ho se a v a i l a b l e

f rom

a t y p i c a l

i n - s e r v i ce JT3C-7 eng ine .

I n r eg a r d

t o

t h e p o s s i b i l i t y

of

l o c k i n g e n gi ne b l e e d op en o r c l o s e d ,

i t was

con vey ed t h a t t h i s c o u l d be d e t r i m e n t a l t o e ng in e t r a n s i e n t o p e r a t i o n . I n

p a r t i c u l a r , t h e JT3C-7 e n g in e t h r u s t l o s s when t h e a u t o m a t i c su r g e b l e e d s a r e

opened on a

low

p ow er a p pr oa c h c o n d i t i o n a t 30 00 f e e t an d 15 0 k n o t s t r u e a i r

speed was es t i m at ed

t o

be ap pr ox im at e l y 327 pounds

or

10%.

21


26/48

TABLE

I11

AND

TEMPERATURES

V S . P R E D I C T E D

QUANTITIES

AVAILABLE JT3C-7 BLEED FLOWS, PRESSURES

P R E D I C T E D

-

G . E .

MODEL

C A S E ( 1 )

C A S E

( 2 )

( i d l e ) ( m a x )

6 3% 98%

( T a m b ( O R ) 550

565

565 550

( B l e e d P r e s s u r e

((Bleed Temp ( O R ) ) 725 725 1181 1181

)

44.9 44.9 174.9 174.9

7;;;;

Flow)

1

.o

1

.o

1.9 1 .9

(Bleed Rat io ) 0.027 0.027 0.012* 0.012*

p s i a )

A v a i l a b l e

HPC

Bleed Pressures and Tempera tures

( f r om

JT3C-7 eng ine a t t he

above b leed

flows)

PTX 30.5 30.5 16 8.3 17 1.9

a t

B leed

P o r t

Blee d Temp. a t

)

737 737 1243 1228

B leed

Port

( O R )

TTX

* =

S l i g h t l y e xc ee ds JT3C-7 s p e c i f i c a t i o n

l i m i t o f

0.012 f o r

HPC

b le ed a i r

f o r maximum cont inuous

to

t a k e o f f p o w e r

Seve ra l recommendat ions were made by P r a t t

&

W h i t n e y r e l a t i n g

t o

f u e l

p r e s s u r e , f u e l t e m p e r a t u r e a n d

o i l

t e m p e r a t u r e

l i m i t s

fo r th e JT3C-7 en gin e.

D u r i n g e ng in e o p e r a t i o n s , f u e l p r e ss u re a t t h e e n gi ne f u e l pump i n l e t s h o u l d

be m a i n t a in e d a t n o t l e s s t h a n 7 .5 p s i a bov e t h e t r u e v a p o r p r e s s u r e

of

t h e

f u e l

to

p reven t vapo r

l o c k a n d /o r pump c a v i t a t i o n

from

o c c u r r i n g a t e l e va t e d

f u e l t e mp e ra t ur es . F u el p r e s s u r e s h o u l d be k e p t b e lo w 55 p s i g d u r i n g e n g i n e

o p e r a t i o n and s h o u l d n o t be a l l o w e d t o e x ce e d 8 5 p s i g a f t e r s hu td ow n when t h e

f u e l p ressu re may i nc r ea se due

t o

t he rma l expans ion o f t h e f u e l . The e n g i n e

f u e l

system

c a n. to le ra te s h o r t d u r a t i o n ( m i l l i s e c o n d s ) p r e s s u r e e x c u r s i o n s

or

s p i k e s o f 10 0 p s i a bo ve t h e pump i n l e t p r e s s u r e . The l i m i t i n g a r e a i s a

s e c t i o n

of

t h e f u e l c o n t r o l w h ic h s ee s pump i n l e t p r e s s u r e an d

i s

capab le

o f

s u s t a i n e d o p e r a t i o n o n l y up

t o

1 1 5 p s i a .

22


27/48

F ue l t e m pe r at u re l i m i t s w ere e s t a b l i s h e d w i t h t h e a s su m pt io n t h a t l o n g

descen ts from h i g h a l t i t u d e s were b ey on d t h e s l o p e o f t h e f l i g h t t e s t s p la nn ed

so t h a t e x t r e m e l y h i g h t e m p er a tu r e r i s e s t hr o ug h t h e f u e l pumps c o u l d b e

avo ided .

I t

was recommended t h a t pump i n l e t t empe ra tu re be l i m i t e d

t o

160F

w i t h o v e rs h o ot s

t o

170F

for

s h o r t p e r i o d s

o f

t i m e o n l y . T h i s

l i m i t

was se t

because

o f

t h e u n k n o w n c o n d i t i o n of t h e l o w t e m p e r a t u r e e l a s t o m e r s e a l s t h a t

w ere p r e s e n t i n t h e e n gi n e f u e l pumps and f u e l c o n t r o l . P r a t t

&

Whi tney

recommends mai n t a i n i ng eng ine o i 1 i l e t tempe ra tures be tween 176 and 21 2F for

e x t en d e d s e r v i c e l i f e . H ow ev er, o i l t e m p e r a tu r e s w er e p e r m i s s i b l e to 270F

w i t h o v e rs h o o ts t o 290F

for

10 m in ut es f o r b o t h g ro un d and i n - f l i g h t

o p e r a t i o n s .

FUEL C H A R A C T E R I Z A T I O N TESTS

AND

ANALYSES

The purpose

of

t h e

l a b o r a t o r y f u el c h a r a c t e r i z a t i o n t e s t s was t o v e r i f y AMK

f u e l b l e n d e d

f o r

t h e C I D p r o gr a m r e a c t e d i n t h e same ma nn er as t h e p r e v i o u s l y

e v a l u a t e d AMK (Ref.

1 ) for f i l t e r a b i l i t y and c om bu st or p e rf or m an c e, a n d t o

a s s e s s t h e d e g r a d a t i o n l e v e l a c h i e v e d by the degrader sys tem

f o r

subsequen t

e n g i n e t e s t s . Two s e t s of f i l t e r r a t i o and t r a n s i t i o n v e l o c i t y mea su r in g

e qu ip me nt we re f a b r i c a t e d b y P r a t t & Whitney for NASA Ames-Dryden F l i g h t

R ese arch F a c i l i t y and t h e F A A Techn i ca l Cen te r . A l i s t o f t he equ ipmen t

c o m p r i s i n g e a c h

o f

t h e

flow

m e as u ri ng d e v ic e s i s p r o v i d e d i n T a bl e C-1

o f

Appendix

C .

Degraded AMK was o b t a i n e d from t h e

F A A

f o r u se i n c a l i b r a t i n g t h e n ew ly

f a b r i c a t e d e qu ip m en t a g a i n s t e qu ip me nt used i n e a r l i e r p ro gra ms a t P r a t t &

Whitney . The f ue l was f u r t h e r deg raded us i ng a Ga u l i n D i s pe r se r or homogenizer

f o r

one pass a t

8000

p s i

( N A S A

CR - 168081 ) be fo re compara t i ve expe r imen ts we re

conduc ted . Resu l t s o f t h e c a l i b r a t i o n s i n d i c a t e d go od a gr ee me nt be tw e en t h e

equipment fo r t h e h i g h l y d eg ra de d

AMK

t es ted . Tab le I V i s a t a b u l a t i o n o f t h e

d a t a r e c or d e d and subsequ ent c a l i b r a t e d f i l t e r r a t i o s . The t r a n s i t i o n

v e l o c i t i e s f o r t h e t h r e e u n i t s o b t a i n e d fro m t h e p l o t s shown i n F i g u r e s 1 5, 1 6

and 17 ar e shown i n Tab le

V .

Tab le I V

FILTER R A T I O S

n i t J e t A T i m e

AMK

Time F i 1 t e r R a t i o

# 1 ( P r a t t

&

Whit ney) 5.33 sec 5.86 1 . 1

#2 ( N A S A Ames-Dryden) 5.41 sec 5.9 3

1 . 1

#3 ( F A A Tech Ce nte r) 5.13 sec 5.68

1 . 1

23


28/48

r

2

P

15

2

I

I

u-

g

10

2

5

u

U

u.

LL

5

0

0 5 10

15 2

25

VELOCITY, CMiSEC

F i g u r e 15 D e t e r m i n a t i o n o f T r a n s i t i o n

V e l o c i t y . U n i t 1

0 15

20

25

VELOCITY, CMlSEC

F i g u r e 1 6 D e t e r m i n a t i o n o f T r a n s i t i o n

V e l o c i t y . U n i t

#2

24

P

2

8 1 5 ,

4

I

$

u-

a

g

10

5

U

kk

Y

n

5

0 5

10

15

20

25

VELOCITY, CMlSEC

F i g u r e 17 D e t e r m i n a t i o n

o f

T r a n s i t i o n

V e l o c i t y . U n i t 3


29/48

TABLE V

T R A N S I T I O N

VELOCITY

T r a n s i t i o n V e l o c i t y

# 1 ( P r a t t

&

Whi tney) 10.5 cm/sec

#2 ( N A S A Ames-Dryden) 10.7 cm/sec

#3 ( F A A Tech Ce nt er ) 10 .5 cm/sec

The f i l t e r r a t i o and t r a n s i t i o n v e l o c i t y m easurement e qu ip m en t w ere d e l i v e r e d ,

s e t

up and demonst ra ted f o r b o t h

NASA

Ames-Dryden F l i g h t R e se a rc h F a c i l i t y a nd

F A A T e c h n i c a l C e n t e r p e r s o n n e l for t h e i r s ub se qu en t u se o n - s i t e .

A

sample

o f

AMK

f u e l , t y p i c a l

of

t h a t u sed i n t h e

C I D

t e s t , was t e s t e d

t o

e s t a b l i s h t h e f l o w c h a r a c t e r i s t i c s and f i l t r a t i o n p r o pe r t ie s as a f u n c t i o n o f

d e gr a da t i on l e v e l a nd t o compare t h e f i l t e r a b i l i t y c h a r a c t e r i s t i c s

o f

t h e

r e c e n t l y b le nd ed f u e l w i t h f u e l t e s t e d d u r in g e a r l i e r

N A S A / P & W

p rog rams . Two

b a tc h es o f f u e l were t e s t e d as a r e s u l t

o f

a bn or ma l l y h i gh f i l t e r r a t i o s f ou nd

i n t h e f i r s t b a t c h

o f

AMK f u e l . I n i t i a l t e s t i n g

o f

t h e f u e l t o d et er mi ne i t s

f i l t e r r a t i o showed u n u su a l l y h i g h

l e v e l s o f f i l t e r r a t i o ( o v e r 5 00 ) . A

p o r t i o n

o f

t h i s f u e l was d e gr ad e d t o a t r a n s i t i o n v e l o c i t y o f 4 .5 and t he n

s u b j e c t e d t o f i l t e r a b i l i t y t e s t i n g . Immediate f i l t e r c l o gg i ng o cc u r re d , even

a t t h e l ow e s t

f l o w

r a t e s . The u n u su a l l y h igh f i l t e r r a t i o s o b ta in e d p r i o r

t o

t he f i l t e r a b i l i t y t e s t i n g was a s cr ib e d t o c on ta m in a t io n from a sample be ing

d ra wn f r o m t h e b o t t o m

o f

a s t o r a q e t a n k . E v a l u a t i o n

of

t h e i n i t i a l b a tc h o f

AMK

f u e l was d i s c o n t i n u e d an d a

e v a l u a t i o n

o f

th e AMK fu e l . The

I m p e r i a l C he mic al I n d u s t r i e s I

A second ba t ch

o f

AMK

fue l samp

c o n s i d e r e d t o be a no rma l l eve l

d i v i d ed i n t o two p o r t i o n s w h i c h

l e v e l s

of

2.0 and 2.7 cm/sec. F

t h e p r e s s u r e d r o p a c r o s s a 1 6

m

i e w

f u e l sample was req ues ted to c o n t i n u e t h e

r e m a in d e r o f t h e c o n t a m i n a te d f u e l w as s e n t

t o

1) f o r a n a l y s i s .

e recorded f i l t e r r a t i o s

o f

57 w h i c h

i s

f o r

unsheared o r v i r g i n AMK. The sample was

were degraded t o t r a n s i t i o n v e l o c i t y ( V T )

l t e r a b i l i t y t e s t s were conduc ted t o measure

c r o n s t a i n l e s s s t e e l s c re e n as a f u n c t i o n

o f

~ ~

AMK

f u e l

flow

a t a m b ie n t t e m p e r a t u re

( R e f . 1 ) .

The f i l t e r t e s t i s de sc r i b ed i n

NASA CR-168081.

Tab le

V I

p r e s e n t s t h e r e s u l t s

o f

t he f i l t e r a b i l i t y t e s t i n g

c o n d u c t e d o n t h e

AMK

f u e l d u r i n g t h i s prog ra m. T a bl e

V I 1

p r e s e n t s t h e d a t a

r e co r de d u nd er c o n t r a c t NAS3-22045. I n t he t a b l e s , f i l t e r c l o g g i n g i s

i n d i c a t e d

fo r

t h o s e v e l o c i t y e n t r i e s w here t h e p r e s s u r e dr o p i s shown as a

r a ng e , r a t h e r th a n as a s i n g l e v a lu e .

R e s u l t s o f t h e f i l t e r a b i l i t y t e s t i n g conducted on t h e second b a t ch

o f AMK

f u e l

i n d i c a t e d t h a t t h e c l o g g in g c h a r a c t e r i s t i c s o f t h e o n - l i n e b l e nd e d

AMK

made

f o r t h e

C I D

p ro gr am a r e v e r y s i m i l a r to

t h e

b a t c h b l e n de d f u e l u n de r

NASA

c o n t r a c t NAS3-22045. T h is t e s t i n g e s t a b l i s h e d t h e c r i t e r i a f o r f i l t e r a b i l i t y

a nd c om b us to r r e q u i r e m e n t s d u r i n g t h e C I D program. Fue l samples ta ke n

downstream

o f

a de gr ad er , w h i l e t h e e ngine o p e r at e d a t i d l e , r e s u l t e d i n

t r a n s i t i o n v e l o c i t y l e v e l s

o f

2 .9 and 3.2 cm/sec whic h was co ns ide red

s a t i s f a c t o r y

for

t h e p l a n n e d m i s s i o n s

o f

the

8-720

a i r c r a f t .

25


30/48

V T

= 2.0

c l o g g i n g

V T = 2 . 1

c l ogg i ng

TABLE V I

FILTERABILITY

T E S T ( 1

6 /J m ABSOLUTE

SCREEN)

1984

A P

psi

0 . 20

0 . 4 0

0 . 6 0

0 . 80

0 . 90

1.30-1 .40

1.60-1.80

2.10-2.30

3.00-3.40

4.00-4.40

5.80-9.40

0 . 10

0 . 3 0

0.50

0 . 80

1 . 10

1.20-1.30

1 .50-1.60

1.90-1.20

2.10-2.60

3.60-4.60

F low Rate

c c l s e c l

1 . o

2 .0

2.7

3.6

4 . 1

5 . 4

6.0

6 . 5

8 . 0

8 . 8

10.4

1 .o

2 . 0

2.8

4 . 0

5.6

6 . 1

1.7

9 . 0

10 . 0

13.4

S u p e r f i c i a l (

V e l o c i t y , c m l s e c

3.1

6 . 3

8.4

11.3

12.8

16.9

18.8

20.3

25.0

21.5

32.5

3.5

6.3

8 . 8

12.5

11.5

19.1

24.1

28.1

31.3

41.9

T r u e V e l o c i t y ( )

cmlsec.

141

210

241

290

312

367

392

406

463

49

1

551

141

210

251

31 3

380

398

455

502

331

665

.............................................................................

I ) S u p e r f i c i a l v e l o c i t y i s b as ed o n p i p e c r o s s - s e c ti o n a l a r e a i n w h ic h t h e

( )

T r u e v e l o c i t y i s based on flow c o e f f i c i e n t c o r re c t ed f l o w a re a from a

f i l t e r

i s

p l a c e d .

J e t

A

c a l i b r a t i o n

for

t h e f i l t e r b e in g te st ed .

TABLE

V I 1

1981 FILTERABILITY T E S T ( 1 6 p m ABSOLUTE S CRE E N) 1981

TEST #45

AP F lo w R a te S u D e r f i c l a l

I

T r u e V e l o c i t v ( )

psi c c l s e c l

VT

=

1.9 0 .30 1 .6

0 . 52 2 . 1

0.69 3.0

c log g ing 0 .94-1 .10 3 .8

1.21-1.49 4.1

2.43-3.80 5.8

v e i o c i ty, cm lsec

5.0

8 . 4

9 . 4

11.9

12.8

18.1

Tes t #34

cm lsec

179

290

303

350

366

44 1

VT

=

2.5 0.65

1.03

c logg ing 1 .28-1 .61

1.62-2.48

2.9-3.1

4.2-5.5

6.9-9.9

12.2-15.6

15.6-1 8.2

3.5

5.3

4.2

8.2

9.4

11.1

13.6

16.4

18.0

10.9

16.6

19.4

25.6

29.4

3 4 . 1

42.5

51.3

56.3

32

1

41 5

451

533

516

643

1 2 0

802

853

.............................................................................

S u p e r f i c i a l

v e l o c i t y i s based on p i p e c r o ss - s e c t io n a l a r e a i n w hi c h t h e

( * ) T ru e v e l o c i t y i s b as ed on

flow

c o e f f i c i e n t c o r re c t ed flow a r e a from a

I )

f i l t e r i s p l a c e d .

J e t A c a l i b r a t i o n for t he f i l t e r b e i n g te st ed .

26


31/48

ENG I NE PERF O RM ANCE

The B-720/JT3C-7 s im u la t io n

for

t h e C I D f l i g h t p l a n s u p p l ie d b y NASA

Ames-Dryden F l i g h t Resea rch F a c i l i t y was rev i ewed and assessed t o be

s a t i s f a c t o r y

from

a n e n g i n e o p e r a b i 1

i

y s t a n d p o i n t . E ng in e s im u l a t e d p a r t

power and t akeo f f power pa rame te rs

w e r e

compared w i t h s i m i l a r p ow er c o n d i t i o n

d a t a f rom in-house and FAA T ec h C e n t e r g e n er a te d g r o un d t e s t d a t a a nd t h e

agreement was good.

I t was n o t e d t h a t t h e r e was some e n g i n e o p e r a t i o n i n t h e

c om pr es so r " b l e e d s o pe n' ' po we r r e g i o n d u r i n g a i r c r a f t a p p ro a c h .

F i gu re 18 shows t y p i c a l JT3C-7 eng in e perfo rmance da ta used as a ba se l i ne

r e f e r e n c e t a k e n

f o r

s tanda r d day a t sea l e v e l s t a t i c c o n d i t i o ns . I n F i gu r e 18,

N ,

r e p r e s e n t s t h e low rotor speed, and N 2 t h e h i g h

rotor

s pe ed , i n RPM,

c o r r e c t e d

t o

sea l e v e l s t a t i c s ta n da r d day c o n d i t i o n s a s a f u n c t i o n

of

e n g i n e

p r e s s u r e r a t i o , P T 7 / P T Z . F igu re 18 p resen t s t he eng ine exhaus t gas

tempera tu re i n deg rees Rank ine , and W F r e p r e s e n ts e ng in e f u e l

f l o w ,

i n

l b s / h r , w i t h b o t h p a ra m et er s c o r r e c t e d

t o

sea l e v e l s t a t i c s t a n d a r d day

c o n d i t i o n s .

h

pc

SLTO

97

N2

EPR

I

2.672

N2 9670

12,000-

1o.ooO

-

a

I,

9

8000-

2

5

v

B

I-

a

a

ImJO-

V

4000-

SLTO

104.8% N 1

IDLE 235

4000 A 1 1

1

1 o

1.5 2.0

2.5 3.c

Y ENGINE

PRESSURE

RATIO, PT~ /PT:

Fi gu re 18 Ty p i ca l JT3C-7 Eng

W

ENGINE PRESSURE RA TIO,

PT7/PT2

ne Per fo rmance (S ta nda rd Day Sea Leve l S t a t i c )

27


32/48

T h e s i g n i f i c a n c e

o f

t h e e n g i n e f u e l flow, exhaus t gas t empera tu re , and t he

ro to r speeds i s t h a t t he s e pa ra m et er s d e f i n e t h e p er fo rm a nc e c h a r a c t e r i s t i c s

o f t h e e ng in e and a r e t h u s an i n d i c a t i o n

o f

e n g i n e " h e a l t h " .

For

example, i f

t h e f u e l flow a nd e x h a u st ga s t e m p e r a tu r e s a r e h i g h e r t h a n n o rm a l a t a g i v e n

e n g i n e p r e s s u r e r a t i o ,

i t i n d i c a t e s a l o s s i n en gi ne e f f i c i e n c y . The b e h a v io r

o f

t h e low and h i gh p res su r e compressor

ro tor

speeds, N , and

N Z ,

p r o v i d e s

an i n d i c a t i o n w h et he r t h e l o s s

o f

e f f i c i e n c y

i s

i n t h e lo w o r i n t h e h i g h

s p o o l .

The expe cted rang e

o f

va lues above and be low the ave rage

of

each

o f

t h e f o u r

per formance

pa rame te rs for a new pr od uc t i on JT3C-7 eng in e has been es t im at ed

t o be as f o l l o w s a t a g i v e n e n gi ne p r e s s u r e r a t i o :

Low

Rotor Speed,

N , -

1.2%

H i g h

Rotor

Speed,

N 2

-

1.2%

Exhaust Gas Temperature

-

30"R

Fuel F low, W F - 2.5%

I t

ho

I d

be n o te d t h a t t h e a bove v a r i a t i o n s r e l a t i v e

t o

a n a v e r a g e p r o d u c t i o n

e n g i n e ar e f o r a n u n i n s t a l l e d e n g in e and do not r e f l e c t a i r f r am e i n s t a l l a t i o n

e f f e c t s , p ower e x t r a c t i o n , e n g in e sy ste m a i r b le e d , and e n gi ne d e t e r i o r a t i o n .

The f o l l o w i n g d i s c u s s i o n c o v e rs t h r e e g ro u ps

o f

p e r f o r m a n c e r e s u l t s :

o b s e r v a t i o n s f o r g ro un d e n gi ne t e s t s a t t h e F A A T ec hn ic al C en te r, f l i g h t t e s t

made

on

September 18, 1984 w i t h bo th

J e t

A

and AMK, and

C I D

o f

December 1,

1984

w i t h A M K o n l y .

FAA Technical Center T e s t s

I n o rd er

t o

e v a l u a t e t h e e n g i ne p e r fo r ma n ce t h a t c o u l d o cc u r i f h e f u e l

d e g r a d e r s h u t down d u r i n g f l i g h t , a JT3C-6 e n g i n e t e s t was c o n d u ct e d w i t h J e t

A

and undegraded AMK f u e l s a t t h e

F A A

T e c h n i ca l C e n t e r . D u r i n g t h e t e s t , f u e l

was

s u p p l i e d from a tan k us in g s tan dar d 6-707 boo s t pumps.

A s

p r e v i o u s l y

d e s c r ib e d , t h e JT3C-6 f u e l c o n t r o l was m o d i f i e d to i n co rp or a t e f i l t r a t i o n

f e a t u r e s m o r e i n l i n e w i t h t h e JFC25-10 C-7 c o n t r o l u s e d i n t h e JT3C-7 e n g i n e s

i n t h e

C I D

a i r c r a f t .

The engine appeared to p e r fo r m s u r p r i s i n g l y w e l l on AMK

t h a t was o n l y s l i g h t l y deg raded (F .R .=30 ) by t he 6-707 boos t pumps. S teady

s t a t e pe rfo rm an ce a t

EPRS

o f 1.5

t o

2 .5 a nd t r a n s i e n t re sp on se c a l i b r a t i o n s ,

w h i l e b u r n i n g AMK, i n d i c a t e d no s i g n i f i c a n t d i f f e r e n c e s f rom b a s e l i n e t e s t s

c o n d u c t e d w i t h

Jet A

f u e l . The o n l y o p e r a t i o n a l a b n o r m a l i t y n o t e d was t h e

immedia te p ressure r i s e i n c re a s e a c ro s s t he i ns tr um e nt ed f u e l f i l t e r l s c r e e n s

up

t o

a s te ad y, l i m i t e d v a l u e ( 5 ) as t h e f u e l was sw i t ched from J e t A to

undegraded AMK.

A s e c o n d t e s t was pe r fo rmed w i t h t he JT3C-6 eng ine us i ng a JT3C-7 f u e l c o n t r o l

s i m i l a r t o t h a t used on t h e C I D a i r c r a f t to e v a l ua te t h e o p e r a b i l i t y of t h e

JT3C-7 c o n t r o l s o n t h e t h e 6 -7 20 t e s t a i r p l a n e when o p e r a t i n g o n u nd e gr ad ed

AMK f u e l . NASA Ames-Dryden F l i g h t R es ea rc h F a c i l i t y r e p o r t e d t h e e n g in e

28


33/48

o pe ra te d s a t i s f a c t o r i l y fo r 41

minutes on undegraded AMK f u e l . P os t t e s t

i n s p e c t i o n

o f

t h e f u e l c o n t r o l

s e r v o

f i l t e r

r e v e a l e d s i g n i f i c a n t a m o u n t s o f

s o f t ge l on t he downs t ream s i de o f t he sc reen . F i l t e r r a t i o m ea su re me nts o f

t h e f u e l i n d i c a t e d l e v e l s

o f

40

f rom

t h e

f u e l

tank and

1 1

f rom

l o c a t i o n s

downstream of t h e boost pumps.

F l i g h t T es ts

F l i g h t

t e s t

da ta was an a lyzed

f rom

t h e 6-720 a i r c r a f t o p e r a t i n g a l t e r n a t i v e l y

w i t h J e t

A

and

AMK

du r i ng f l i g h t 9 on Sep tember 18,1984 . F i g u r e 19 shows Je t

A

a nd de gr ad ed AMK t e s t p o i n t s p l o t t e d w i t h

a

t y p i c a l b a s e l i n e JT3C-7 e n g i n e

pe r fo rmance cu rve

f o r

a s t a n d a r d d ay a t s e a l e v e l

s t a t i c c o n d i t i o n s . The

per fo rmance o f t h e f o u r f l i g h t

t e s t

p o i n t s i n te rm s of t s p e e d , f u e l

flow

W F ) , and exhaus t gas tempera ture ( E . G . T . )

i s

h i g h e r t h e n t h e t y p i c a l J T 3 C - 7

sea l e v e l s t a t i c (S.L.S.) per fo rmance. Th is d i f fe re n ce was expec ted because:

1 )

t h e f l i g h t t e s t d a t a a re a t a pp ro xi ma te ly

0.3

Mn r a t h e r t h a n a t

S . L . S . ,

2)

t h e f l i g h t e n g in e s h ad un d o ub t ed l y d e t e r i o r a t e d due t o age and h igh-eng ine

t imes and

3)

t h e f l i g h t e ng in es c o u l d d i f f e r due t o i n s t a l l e d e f f e c t s ( a i r

b l e e d , p o we r e x t r a c t i o n e t c . ) . H ow ev er, t he s l o p e o f t h e f l i g h t t e s t d a ta

a gr ee s c l o s e l y w i t h t h e t y p i c a l

eng ine s l ope and t he re i s e s s e n t i a l l y n o

d i f f e r e n c e i n p e r fo rm a nc e b etw een

AMK

and Jet

A

f u e l .

12,000

10,000

a

I,

5

8000

2

5

2.

8 6000-

u

4000

2000

0

4

160

M

a

u

;

400-

3

Q:

5

2 1200-

v

c1

1.5

2 0 2 5

3.0

ENGINE PRESSURE RATIO, PT,/PT,

1 o

-

-

-

-

-

FLIGHT

TEST

DATA 9~18-84

ET A

MN=.3

A AMK MNZ.3

0 0 0 ~.5 3.0

I 1 0 1 5 2.0

ENGINE PRESSURERATIO. PT,IP~,

F i g u r e 1 9

F l i g h t T e s t Data Compared

t o

B a s e l i n e P e r fo r m a nc e

29


34/48

C I D T e s t

Data taken f rom t h e 8-720 t e s t a

t h e C I D

t e s t

on December 1 , 1984

be fo re q round impac t . Th ree da ta

r c r a f t o p er a t in g

were ana lyzed

t o

p o i n t s r e p r e s e n t

s e l e c t e d f o r each o f t h e f o u r e n q i n es . The D o i n t s

w i t h AMK d u r i ng f l i g h t 15 o f

e v a l u a t e e n g i n e p e r f o r m a n c e

n g t h r e e p ow er l e v e l s w ere

r a n g e d from Mn 0.15 t o 0.25

a t a l t i t u d e s o f

2000

to

4500

fee t . The lowest p ow er p o i n t s e l e c t e d was r e c o r d e d

t h r e e seconds b e f o r e g ro un d i m p a ct . The r e s u l t s a r e p l o t t e d i n F i g u r e 20 and

were compared t o t h e d a t a ta ke n d u r i n g f l i g h t 9 and t o a t y p i c a l u n i n s t a l l e d

b a s e l i n e

for

a JT3C-7 en gin e. Th is

c om pa ris on showed n o s i g n i f i c a n t d i f f e r e n c e

i n e n g in e p er fo rm a nc e f o r C I D f l i g h t s 9 and 15.

The f o u r f l i g h t e ng in e s us ed

d u r i n g t h e

C I D

pe r fo rmed as expec ted .

NPICA L JT3C-7 ENGINE

PERFORMANCE (STANDARD

DAY SEA LEVEL STATIC)

10.000

U

FLIGHT TEST DATA

9-18-84

ET A MN I O

A MK MN= 0 3

v

m

V

6

CID FLIGHT 15

12-1-84

MN

0 15 TO 0

5

NG NO 1

NG NO 2

h NG NO 3

6 NG NO 4

I I

I -I

2 0 2 5 3 0

1 5

5000

10

ENGINE PRESSURE RATIO, P T ~ / P T ~

l 2 * O o 0 r

FLIGHT TEST

D A T A

9-18-84

/

PERFORMANCE (STANDARD

ET A MN 0.3

A

MK

MN o 3 WPICA L JT3C-7 ENGINE

I

DAY SEA L EVEL STATIC)

10,000

CID FLIGHT 15 12-1 84

MN 0.15 TO 0.25

v)

9 8000 ENG NO. 2

ENG NO. 3

0 ENG NO. 4

-

U

U

8 6000

I,

5

4000

I a

3

SECONDS

RFFORE IMPACT

600

/

YPICAL JT3C-7 ENGINE

PERFORMANCE STANDARD

DAY SEA LEVEL STATIC)

I

I 1

2 0

2 5

3.0

1 0 1.5

ENGINE PRESSURE

RATIO,

PT,/PT12

F igu re 20

F l i g h t a n d C I D T e s t Data Compared to Base l i ne Pe r fo rmance

30


35/48

CONCLUDING

REMARKS

f u e l c h a r a c t e r i z a t i o n s and a re v i e w

o f

JT3C-7 eng,ne pe r form anc e a r e

documented for a B-720 t e s t a i r p l a n e o p er at ed on an a n t i m i s t i n g k er os en e

AMK )

f u e l .

The f o u r e n g i n e s w e r e m o d i f i e d b y a dd in g a f u e l d e g r ad i n g s y st em t o

i m p r o v e t h e

f l o w

q u a l i t i e s

o f

t h e f u e l i n t h e en g in e . These e v a l u a t i o n s w e r e

made

fo r

a g r o u n d t e s t e n g i n e a n d

for

t h e f l i g h t e ng in es , c u l m in a t in g i n th e

C o n t r o l l e d I m p a c t D e m o n s t r a t i o n ( C I D ) December 1 , 1984 . The fo l l o w in g r e s u l t s

w e r e o b t a i n e d :

o

Flow

c h a r a c t e r i z a t i o n t e s t s on de gra ded

AMK

f u e l sa mples i n d i c a t e d l e v e l s

o f d e g r a d a t i o n s a t i s f a c t o r y

for

t h e p l a n n e d s e a l e v e l

e n g i n e t e s t s a n d

s h o r t f l i g h t t im e, low a l t i t u d e m i s s i o n s of t h e 8-720 a i r c r a f t .

o

T h e o p e r a b i l i t y a n d p e r f o r m a n c e

of

t he JT3C-7 eng ines op er a t in g on

degraded

AMK

were comparable

to

r e s u l t s w i t h J e t

A

f o r

t h e f l i g h t

c o n d i t i o n s a s s e s s e d d u r i n g t h i s p r o g r a m .

o

The per formance

of

t h e f o u r f l i g h t eng ines d u r i n g f l i g h t and

t o

ground

i mp ac t was s a t i s f a c t o r y f o r t h e

C I D

m i s s i o n .

31


36/48

APPEND I X

A

JT3C-7 ENG I NE

32


37/48

v

v

m

.

3

l

.

-

a

L

L L

a

.


38/48

- a . .

ORGDNAL PAGE IS

4 O

POOR

QUALITY


39/48

ORlGlN L

P GE

IS

OF

POOR QU LITY

tu

Y

n

n

Q

aJ

aJ

>

I.

aJ

U

m

aJ

L

r

LL

35


40/48


41/48

7

ORlGlM L

P GE

IS

O

POOR

QU LITY

m

W

a

_

c

-c

m

In

a

a


42/48

A P P E N D I X

B-1

d r a i n o u t o f t h e t u b e . The t i m e r e q u i r e d for t he men i scus o f t h e f u e l

t o

pass

between the two r e f e re nc e marks on t he t u be was rec o rded . Th i s p roced u re was

PROCEDURE

FOR D E T E R M I N I N G

FILTER

R A T I O

38

I


43/48

a i

39

a

U

.-

I

m


44/48

A P P E N D I X 8-2

1 .

2.

3.

4.

5 .

6.

7.

PROCEDURE FOR D E T E R M I N I N G TH E T R A N S I T I O N VELOCITY

( A

Measure

o f AMK

D e g r a

Documents

An timisting Fuel System Kerosene JT3 Engine Integration Study