Analysis of the T63-A-700

John S. Glaeser Depot Engineering and R

DOTIFAAICT-TN90118

on file at the Technical Center

US. Department of Trarispcftation

Federal Aviation Administration

rbine

Technical Center Atlantic City International Airport, N.J. 08405

NOTICE

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T a c h n i c o l Repod Oosumantot ion Page -"- -- 1. Report No. 2. Government Accesston No. T DOT/FAA/CT-T~90/18 --- 4 T i t l e ond $vbti;le

ANALYSIS OF THE T63-A--700 ENGINE USED I N ALCOHOL TURBINE FIJEL EXTENDER TEST

- -- 7. Author's)

John S. G l a e s e r -- --

9. Performing Organization Nome and Address

Depot Engineer ing and RCM Suppor t O f f i c e U.S. Army A v i a t i o n Systems Command Naval A i r S t a t i o n , Corpus C h r i s t i , Texas

12. Sponsoring Agency Nome ond Address

U.S. Department of T r a n s p o r t a t i o n F e d e r a l A v i a t i o n Admini s t r a t i o n T e c h n i c a l Cen te r A t l a n t i c C i t y I n t e r n a t i o n a l A i r p o r t , N J 08405

- -. 3. Recipnent's Catolog No.

---- -- 5. Report Dote

August 1 990 -- --- 6. Performing Orponitation Cod*

8 . Perform~ng Orgon~zo t~on Report NO.

DOT/FAA/cT-TN90/18 10. Work Unit No. [TRAIS)

1 1 . Contract or Gront No.

13. Type o f Report ond Per iod Covered

T e c h n i c a l Note

14. Sponsoring Agency Code

ACD-2 10

15. Supplementory Not01

COTR: Augusto F e r r a r a

-- 16. Abstract

The teardown a n a l y s i s of t h e T63-A-700 eng ine used i n f u e l e x t e n d e r r e s e a r c h a t t h e F e d e r a l Avia t ion A d m i n i s t r a t i o n (FAA) T e c h n i c a l Cen te r was conducted by t h e TJnited S t a t e s Army A v i a t i o n Systems Command (AVSCOM) Depot Engineer ing and R e l i a b i l i t y Centered Maintenance Support O f f i c e (DERSO) i n o r d e r t o a s s i s t t h e FAA i n complet ing an e v a l u a t i o n o f t h e u s e of a l c o h o l s a s e x t e n d e r s f o r t h e e x i s t i n g t u r b i n e f u e l s .

The t u r b i n e s e c t i o n of t h e T63-A-700 eng ine d i s p l a y e d burned vanes on t h e f i r s t s t a g e gas producer . I n a d d l t i o n , t h e b l a d e t i p s o f t h e second s t a g e g a s p roducer t u r b i n e r o t o r had rubbed t h e i n t e r i o r of t h e second s t a g e gas p roducer n o z z l e . It was concluded t h a t t h e v a n e s on t h e f i r s t s t a g e g a s p roducer burned d u r i n g a s e r i e s of h o t o r hung starts u s i n g e x t e n d e r f u e l s . The i n e f f i c i e n c y of b o t h t h e f u e l n o z z l e and t h e f u e l c o n t r o l u n i t u s i n g a l c o h o l b l e n d s d u r l n g s t a r t i n g o p e r a t i o n s caused t h e o v e r t e m p e r a t u r e s . The second s t a g e g a s p roducer n o z z l e was warped a s a r e s u l t of t h e r m a l c y c l i n g from ambient t e m p e r a t u r e t o a h o t o r hung s t a r t c o n d i t i o n t h a t caused t h e t u r b i n e r o t o r t i p s t o r u b t h e n o z z l e . The remainder of t h e eng ine , i n c l u d i n g t h e s e a l s , f u e l c o n t r o l u n i t , f u e l n o z z l e , b e a r i n g s , and i n t e r n a l components, showed no d i s c r e p a n c i e s . Much of t h e change a p p e a r s t o have r e s u l t e d from hung s t a r t s . F u t u r e e v a l u a t i o n s of e x t e n d e r f u e l s s h o u l d c o n s i d e r u s i n g d e s i g n f u e l s d u r i n g s t a r t i n g o p e r a t i o n s and t h e n i n t r o d u c i n g e x t e n d e r f u e l s a f t e r t h e eng ine h a s reached normal o p e r a t i n g c o n d i t i o n s . - - -

17. Kay Words 18. D~s t r ibu t ion Stctemmt

Document is on f i l e a t t h e Techn ica l A l t e r n a t e F u e l s , Alcohol , Cen te r L i b r a r y , A t l a n t i c C i t y I n t e r n a t i o n a l Turb ine Engine, Teardown, A i r p o r t , New J e r s e y 08405 I n s p e c t i o n I--

---- --- 19. Security Clossif . (of this report) 20. Security Clasr i f . (of this

TJnclass i f ied - U n c l a s s i f i e d -- Form DOT F 9700.7 (8-72) Reproduction of completed poge outhorized

22. Pr ice T----

ACKNOWLEDGEMENTS

The t e c h n i c a l a s s i s t a n c e provided by the fo l lowing AVSCOM and CCAD personnel was inva luab le i n completing t h i s r e p o r t :

Ed Ledwig Joe Stephens

J e s u s Vela

Ed Wilson

Charl-es Warren

Norman Brinke r

AVSCOM Engine Technology Sec t ion

AVSCOM Technica l Management Sec t ion

CCAD Engine Pre-Shop Analysis Sec t ion

CCAD Ana ly t i ca l I n v e s t i g a t i o n Branch

CCAD M e t a l l u r g i c a l Branch

TABLE OF CONTENTS

EXECUTIVE SUMMARY

INTRODUCTION

VISUAL INSPECTION

TEST CELL

TEARDOWN

ENGINEERING ANALYSIS

CONCLUSIONS

L I S T OF ILLUSTRATIONS

F i g u r e

1 F u e l C o n s u m p t i o n C o m p a r i s o n

2 O u t p u t Power C o m p a r i s o n

3 T h e A f f e c t e d T r a i l i n g E d g e s

4 T r a i l i n g Edge Showing I n c i p i e n t M e l t i n g

L I S T OF TABLES

T a b l e

1 P e r f o r m a n c e R a t i n g s

2 G a s T u r b i n e E n g i n e T e s t L o g S h e e t

3 L e a d i n g P a r t i c u l a r s

P a g e

v i

1

1.

2

2

3

3

P a g e

5

5

6

6

P a g e

7

8

10

EXECUTIVE SUMMARY

The teardown a n a l y s i s of t h e T63-A-700 engine used i n f u e l ex tender r e s e a r c h a t t h e Fede ra l Avia t ion Adminis t ra t ion (FAA) Technical Center was conducted by t h e TJnited S t a t e s Army Aviat ion Systems Command (AVSCOM) Depot Engineering and R e l i a b i l i t y Centered Maintenance Support O f f i c e (DERSO) i n o rde r t o a s s i s t t he FAA i n completing an eva lua t ion of t h e use of a l c o h o l s a s ex tenders f o r t h e e x i s t i n g t u r b i n e f u e l s .

The t u r b i n e s e c t i o n of t he T63-A-700 engine d isp layed burned vanes on t h e f i r s t s t a g e gas producer. I n a d d i t i o n , t h e b l ade t i p s of t h e second s t a g e gas producer t u r b i n e r o t o r had rubbed the i n t e r i o r of t h e second s t a g e gas producer nozz le .

It was concluded t h a t the vanes on t h e f i r s t s t a g e gas producer burned dur ing a s e r i e s of ho t o r hung s t a r t s u s ing extender f u e l s . The i n e f f i c i e n c y of both t h e f u e l nozz le and the f u e l c o n t r o l u n i t u s ing a l c o h o l b lends dur ing s t a r t i n g o p e r a t i o n s caused the overtemperatures .

The second s t a g e gas producer nozzle was warped a s a r e s u l t of thermal c y c l i n g from ambient temperature t o a ho t o r hung s t a r t cond i t i on t h a t caused t h e t u r b i n e r o t o r t i p s t o rub t h e nozz le .

The remainder of t he engine, i nc lud ing t h e s e a l s , f u e l c o n t r o l u n i t , f u e l nozz le , bea r ings , and i n t e r n a l components, showed no d i sc repanc ie s .

Much of t he change appears t o have r e s u l t e d from hung s t a r t s . Future eva lua t ions of ex tender f u e l s should cons ider u s ing des ign f u e l s during s t a r t i n g o p e r a t i o n s and then in t roduc ing extender f u e l s a f t e r t h e engine has reached normal ope ra t ing cond i t i ons .

INTRODUCTION

The Federa l Aviation Adminstration (FAA) Technical Center eva lua ted t h e performance of a lcohol a s ex tenders f o r rhe e x i s t i n g a v i a t i o n t u r b i n e f u e l s . The eva lua t ion , which was conducted a t the FAA Technical Center dynamometer f a c i l i t y , used a T63-A-700 engine. The engine used i n t h i s p r o j e c t was loaned t o t h e FAA by the United S t a t e s Army Aviat ion Systems Command (AVSCOM).

Various experimental f u e l b lends were evaluated i n t h e T63-A-700 s t a t i c t e s t c e l l t e s t s . These blends cons i s t ed of e i t h e r e thano l o r methanol mixed wi th e i t h e r JP-4 o r Jet-A, and t h e a l coho l concent ra t ion v a r i e d from 5 t o 20 percent . The engine accrued approximately 120 t o t a l hours dur ing t h e eva lua t ion .

It was decided t h a t a teardown a n a l y s i s of t he engine would not be performed a t t he FAA f a c i l i t y i n A t l a n t i c C i ty , N J . The engine was shipped t o t h e Corpus C h r i s t i Army Depot (CCAD) a f t e r completion of t h e eva lua t ion .

The AVSCOM Depot Engineering and R e l i a b i l i t y Centered Maintenance Support Off ice (DERSO) a s s i s t e d the FAA i n t h e f i n a l eva lua t ion . DERSO i s co l loca t ed wi th t h e CCAD complex a t t he Naval A i r S t a t i o n , Corpus C h r i s t i , TX. DERSO ass igned a p r o j e c t engineer t o conduct t he teardown a n a l y s i s of t h e engine.

A four-point p ro j ec t p lan t o complete t he engine teardown a n a l y s i s was developed. It included a v i s u a l i n spec t ion , a t e s t c e l l run t o determine t h e ope ra t ing c h a r a c t e r i s t i c s , a complete teardown inspec t ion t o determine f a i l u r e modes of i n t e r n a l components, and an a n a l y s i s of a l l i n t e r n a l engine and f u e l c o n t r o l u n i t s e a l s f o r d e t e r i o r a t i o n . Emphasis was placed on t h e engine ho t ( t u rb ine ) s e c t i o n and the f u e l system. Funds f o r t h i s p r o j e c t were l i m i t e d and allowed no a d d i t i o n a l a n a l y s i s .

VISUAL INSPECTION

The T63-A-700 engine, s e r i a l number AE403067BCDY was inspec ted a t t h e CCAD Engine Pre-shop Analysis Sect ion t o i n s u r e t h a t t h e engine was t e s t - c e l l ready. The hot s e c t i o n of the engine d isp layed a carbonlexhaust bu i ldup on t h e e x t e r i o r of t he engine case . This buildup i s suspected t o be from ho t o r hung s t a r t s r e s u l t i n g from use of the a l t e r n a t e f u e l mixtures .

The f u e l system had been modified t o inc lude a T - f i t t i n g i n t he f u e l l i n e p r i o r t o t he f u e l con t ro l u n i t . This modi f ica t ion was used f o r f u e l p re s su re measurements. The engine t u r b i n e s e c t i o n r o t a t e d f r e e l y by hand and exh ib i t ed no binding o r rubblng. Therefore, t h e engine was t r a n s f e r r e d t o t h e t e s t c e l l f o r an o p e r a t i o n a l t e s t .

TEST CELL

The f u e l used during t h i s t e s t run was MIL-J-5624, JP-4.

The engine was placed i n t e s t c e l l number 9. Pre- tes t t roubleshoot ing revea led t h a t t he i g n i t i o n e x c i t e r was inoperable . A s e r v i c e a b l e e x c i t e r was i n s t a l l e d , and t h e engine s t a r t e d normally.

The engine o i l consumption during the t e s t c e l l run w a s normal.

The s p e c i f i c f u e l consumption f o r t he engine was c o n s i s t e n t l y h igher than the maximum al lowable ( f i g u r e 1 ) .

Ex t r apo la t ion of the t e s t c e l l d a t a i n d i c a t e s t h a t t h e engine w i l l produce r a t e d power a t 105 percent N 1 speed, 1484 OF t u r b i n e o u t l e t temperature, and 93.5 foot - pound-force ( f t - l b f ) to rque , when co r rec t ed t o s tandard day, s e a l e v e l condi t ions . Obviously, t h e engine was not run i n t h e t e s t c e l l a t t h e s e cond i t i ons a s the maximum ope ra t ing temperature was 1380 OF ( t a b l e 1 ) .

The engine was operated through a l l ranges of power s e t t i n g s . Table 2 r e f l e c t s t he t e s t run parameters. A t a l l power s e t t i n g s , t h e s h a f t horsepower ( r e f e r r e d t o s tandard day, sea l e v e l condi t ions) was lower than the minimum s p e c i f i e d i n TM55-2840-231-23, Aviat ion Unit and In te rmedia te Maintenance Manual, Engine Assembly ( f i g u r e 2) .

Af te r the f u n c t i o n a l t e s t , t he engine was t r a n s f e r r e d t o t h e CCAD Engine Pre-Shop Analysis Sec t ion a r e a f o r teardown a n a l y s i s . The f u e l c o n t r o l u n i t and the f u e l nozzle were t r a n s f e r r e d t o t he CCAD Fuel Control Shop f o r a n a l y s i s .

The engine disassembly revea led s e v e r a l d i sc repanc ie s i n t he hot s e c t i o n . The f i r s t s t a g e gas producer nozzle vanes had burned t r a i l i n g edges. One 3-vane s e c t i o n of t he nozzle was burned more heav i ly than t h e remainder of t h e vanes ( f i g u r e 3) .

The second s t a g e gas producer t u r b i n e r o t o r b lade t i p s had rubbed t h e top and bottom of the second s t a g e gas producer nozz le cy l inde r . Dimensional checks were conducted on the gas producer nozzle . The only discrepancy was t h e f l a t n e s s of the forward f l ange face which i s ad jacen t t o t h e c y l i n d e r . When t h e f a c e s were measured on a f l a t measuring t a b l e , one f a c e of t h e nozzle f l ange was found t o be 0.006 inch high. This is an i n d i c a t i o n of nozz le warpage. The h igh p o i n t was loca t ed 90 degrees from the rubbed a r e a s of t h e cy l inde r .

The number e i g h t bear ing had some d i s c o l o r a t i o n , which ind ica t ed some s l i g h t overhea t ing i n t h e gas producer s e c t i o n of t h e t u r b i n e assembly.

The fue l c o n t r o l components were a l l i n working order . The f u e l c o n t r o l s e a l s had no evidence of d e t e r i o r a t i o n . The f u e l nozz le was c l ean and showed no d i sc repanc ie s which would have a l t e r e d t h e f u e l atomizing p a t t e r n .

The remainder of the engine components d i sp layed no d e f e c t s .

ENGINEERING ANALYSIS

F i r s t s t a g e gas producer nozz le - The nozzle was analyzed a t t h e CCAD Meta l lu rg i ca l Laboratory. An examination of t h e burned cross-sec t ion confirmed - i n c i p i e n t me l t i ng i n t h i s a r e a of t h e nozz le ( f i g u r e 4) . The number of engine hours a t t h e time the nozzle s t a r t e d t o burn is unknown. The type of f u e l i n use and the engine ope ra t ing parameters when t h i s f a i l u r e commenced i s a l s o unknown; however, t h e following hypothes is i s probable. The in spec t ion of t h e f u e l nozzle and the f u e l con t ro l u n i t i n s t a l l e d I n t h i s engine revea led t h a t t hey were ope ra t ing normally. The f u e l a tomiza t ion p a t t e r n f o r t h i s nozz le was proper f o r normal ope ra t ing condj t ions . However, t he a l coho l f u e l mix tures may have a l t e r e d t h e flame p a t t e r n during s t a r t i n g and low power requirements , p a r t i c u l a r l y dur ing hot and/or hung s t a r t s . I n a d d i t i o n , t h e flame speed when ope ra t ing on a l c o h o l f u e l s i s slower, and i t i s p o s s i b l e t h e flame f r o n t extended beyond t h e burner can. This f u r t h e r compounds t h e overtemperature problem dur ing a h o t o r a hung s t a r t .

Second s t a g e gas producer nozz le - The dimensional check of t h e nozz le i nd ica t ed warpage a t a po in t 90 degrees from t h e r o t o r t i p rub marks. The rub marks were 180 degrees a p a r t and were uneven i n l eng th and depth. This would confirm warpage a t only one po in t on t h e nozz le a s measured i n t he l abo ra to ry . The cause f o r t he nozz le warpage was most l i k e l y due t o h ighe r than normal s t a r t i n g temperatures from the a l coho l b lends and was aggravated by t h e burned nozz le vanes dur ing s t a r t i n g . Thermal cyc l ing from ambient temperatures t o a start o r h o t s t a r t cond i t i on may have con t r ibu ted t o t h e warping. A p o r t i o n of t h e vanes a l s o burned away. Heat t r a n s f e r between the vanes and t h e per imeter of t h e nozz le increased allowing a more r a p i d thermal cyc l e t o t h e u n i t .

Second s t a g e gas producer t u r b i n e r o t o r - The b lade t i p s of t h e r o t o r had rubbed the second s t a g e nozzle due t o t h e warpage and e l l i p t i c a l shape of t h e nozz le i t s e l f . The r o t o r blade t i p s were worn due t o t h e rubbing. Th i s rubblng e f f e c t may have r e s u l t e d i n hung s t a r t s u n t i l t h e b lades t i p s had worn and t h e nozz le gouge was deep enough t o a l low freewheel ing of t h e t u r b i n e i n t h e nozz le .

CONCLUSIONS

The behavior of the engine i n t h e t e s t c e l l run (low s h a f t horsepower and h igh s p e c i f i c f u e l consumption) was confirmed during teardown and a n a l y s i s and revea led the i n e f f i c i e n c y of t h e burned f i r s t s t a g e gas producer nozz le vanes.

It is probable t h a t the e thano l and methanol b lends wi th j e t f u e l i n f luenced the e f f i c i e n c y of both the f u e l c o n t r o l u n i t and t h e f u e l nozz le , p a r t i c u l a r l y dur ing engine s t a r t i n g opera t ions .

It i s unknown how o r when t h e f i r s t s t a g e gas producer nozzle was exposed t o temperatures high enough t o burn t h e nozz le vanes. The engine a n a l y s i s i n d i c a t e s t h a t some combination of blended f u e l s and a ho t o r hung s t a r t p r e c i p i t a t e d t h e problem.

It i s a l s o unknown what e f f e c t t h e damaged hot s e c t i o n had on t h e r e s u l t s of t h e eva lua t ion i t s e l f . It i s p o s s i b l e t h a t c o n s i s t e n t r e p r o d u c i b i l i t y of t h e eva lua t ion r e s u l t s were a f f e c t e d a f t e r t h e hot s e c t i o n of t h e engine became damaged.

Assuming t h a t t he a l coho l b lends con t r ibu ted t o t h e hot s e c t i o n damage during s t a r t i n g ope ra t ions , i t fo l lows t h a t cons ide ra t ion should be given t o us ing only j e t f u e l t o s t a r t gas t u r b i n e engines. Extender f u e l s would be introduced a f t e r t he engine reached normal ope ra t ing cond i t i ons . This would r e q u i r e a d d i t i o n a l t e s t i n g t o confirm t h e above assumption. The Federa l Aviat ion Adminis t ra t ion Technical Center r epo r t ed t h a t t h e inc idence of hung s t a r t s was reduced by s t a r t i n g the t e s t engine on e i t h e r n e a t Jet-A o r n e a t JP-4.

1 a I x RCTURL o MAXIMUM RLLOWRBLE I Ln & 0.90, J u

Z 0 " I- 0.m a 5 3 Ln 0-----__5 I E *------- z -------a

0.70 -----------

POWER SETTING ( % N1) FIGURE 1. FUEL CONSUMPTION COMPAKISON ---

X f3CTURL OUTPUT O MINIMUM REQUIRED OUTPUT

POWER SETTING ( Z N11 FIGURE 2. OUTPUT POWER COMPARISON

F I G U R E 3. THE AFFECTED T R A I L I N G EDGES

F I G U R E 4. T R A I L I N G EDGE SHOWING I N C I P I E N T M E L T I N G

Ram power Gas Specific fuel rating Measured

Net jet producer consumption torque at rated gas Shaft HP thrust Ib speed rpm Output IblSHP-hr output shaft temp O F ("C)

Rating (min) (min) (5%) (est) shaft rpm (mad ft-lb (max) (max)

'Rakeoff

Normal

90% normal

7 5 4 normal

Start and idle

Flight auto- ration

317 33

270 28

243 26

203 2 1

35 max 10 may

0 max 10 max

NOTE. Specific fuel consumption = fuel flow1SHP

; I t . . 1h 1 Pi .-

'I 4- . . I r. ? l-4 .-

m s . . M h r) T.1

r.

.-h . . M h M f4 .-

117 -4 . , GI rx r) F1

.-

h 4

r- r' M r . .-

.. -x > It- .- .-

1-4 .3

M I? o +-

o m 'J1-0 t.1 t.1 .- .- \a h . ' .- .- r-. r> . . -0 -0 0 0 C .-

00 b-I-

W M LLLL

Rimensions Length ~ e i ~ h t Width

Engine weight (dry). 1'63-A-700

TABLE 3. LEADING PARTICULARS

Maximum oil consumption

Lubricat ing oil specifications

Fuel specifications Pr irnary Al te rna te Ernergency

Design power output R a m power ra t ing

Design speeds: G a s producer (N 1 ) Power tu rb ine (N2) Power o u t p u t sha f t

40 4 inches (1.03 m ) 22.5 inches (0557 m ) 19.0 inches (0.48 m )

138.5 pounds (62.82 kgr.)

0.05 gallhr C6 5 ozlhr)

MIL-T-5624 (JP-4) MIL-T-5624 ( J P - 5 ) ( JP-8) ( JET-A) (JETA-1) M1L.G-5572

317 s h p 335 shp

*US GOVERNMENT PRINTING OFFICE. 1~90-70b061/?0121

10