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Produced by the NASA Center for Aerospace Information (CASI)
CC.) 7U C "L AL41!!@ AU1 CSLL 1!t' G3 /o'j 141a-4

DGE/NASA/0167-8

r 1ASA CR- 174809

'ARRETT NO. 31-3725(8

ADVANCED GAS TURBINE (AGT)

TECHNOLOGY DEVELOPMENT

EIGHTH SEMIANNUAL PROGRESS REPORT

(JULY 1983 -- DECEMBER 1983)

Engineering Staff of

Garrett Turbine Engine Company

A Division of The Garrett Corporation

JUNE 1984

Prepared for

NATIONAL AERONAUTICS

Lewis Research Center

Cleveland, Ohio 44135

Under Contract DEN3-167

AND SPACE ADMINISTRATIO

r-r. • a

for

U.S. DEPAR rMENT OF ENERGY

Office of Vehicle and Engine Research

Technology Development and Analysis

Washington D.C. 20585

and Development

Division
DOE/NASA/0'67-8

NASA CR-174809

GARRETT NO, 31-3725(8)

ADVANCED GAS TURBINE (AGT)

TECHNOLOGY DEVELOPMENT

EIGHTH SEMIANNUAL PROGRESS REPORT

(JULY 1983 — DECEMBER 1983)

Engineering Staff of

Garrett Turbine Engine Company

A Division of The Garrett Corporation

JUNE 1984

Prepared for

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

Lewis Research Center

Cleveland, Ohio 44135

Under Contract DEN3-167

for

U.S. DEPARTMENT OF ENERGY

Office of Vehicle and Engine Research and Development

Technology Development and Analysis Division

Washington D.C. 2058

Lt
^l j

T

a

^I

i

TABLE OF CONTENTS

1.0 SUMMARY

1.1 Power Section Development

1.2 Compressor Development

1.3 Turbine Development

1.4 Combuster Development

1.5 Regnerator Development

1.6 Ceramic Development

1.7 Rotor Dynamics/Foil Bearing Development

2.0 INTRODUCTION

3.0 POWER SECTION DEVELOPMENT

3.1 Rotor Dynamic Development

3.2 Ceramic Engine Development

4.0 COMPONENT/SUBSYSTEM DEVELOPMENT

4.1 Compressor

4.2 Turbine

4.3 Combustion

4.4 Regenerator Development

4.4.1 Ford Regenerator Development

4.4.1.1 Regenerator Cores

4.4.1.2 Regenerator Seal- Cooled Diaphragms

4.4.1.3 Regenerator Seals - Performance Development

4.4.2 Regnerator Development (GTEC)

4.5 Ceramic

4.5.1 Materials

4.5.1.1 Ceramic Material Testing Summary

4.5.1.2 Turbine Diffuser/Insulation Evaluation

4.5.2 AGT101 Ceramic Component Thermal Screening

4.5.3 Ceramic Structures Rig Testing

4.5.4 Ceramic Turbine Rotors

4.5.4.1 Ceramic Material Development

4.6 Rotor Dynamic/Foil Bearing Development

ill QG PAG1 DLAT1l{ 1,10T F?1'+?fi":]7
TABLE OF CONTENTS (Contd)

Page

4.6.1 Rotor Dynamic Rig Testing 39

4.6.2 Analysis 39

4.6.3 Alternate Bearing Systems 41

APPENDIX, A

1.0 TASK 2.3 - CERAMIC ROTOR 47

1.1 Material Development and Characterization 47

1.2 Bladed Rotor Fabrication 47

2.0 TASK 2.7 - STATOR 48

2.1 Molded Stator Processing 4B

2.2 Fillet Crack Investigation 48

3.0 TASK 2.7 FLOW SEPARATOR HOUSING 49

APPENDIX B

1.0 SUMMARY 51

2.0 ROTOR-MATERIALS AND FABRICATION DEVELOPMENT 51

3.0 CERAMIC STRUCURES

APPENDIX C

1.0 BACKGROUND

2.0 SUMMARY

3.0 STATIC STRUCTURES

3.1 Turbine Stator

3.2 Turbine Shroud

3.3 Combustor Baffle

3.3.1 Combustor Baffle (Cast)

3.3.2 Combustor Baffle (Plastic Forming)

3.4 Transition Duct

3.5 Combustor Liner

3.6 Regenerator Shield

iv

53

53

53

53

54

54

55

55

56

56

56
TABLE OF CONTENTS (Contd)

Psae

APPENDIX D

LIST OF SYMBOLS, ABBREVIATIONS AND ACRONYMS 59

REFERENCES 64 
{ LiST OF FIGURES 

C

Figure Title page 

1 ACT101 Program Schedule 4

2 Rotor Exhibits Subsynchronous Conical Motion Which Limits Engine Speed 5

3 Rotor/Bearing System Clearance 7

4 Configuration Differences 8

5 Compressor Backshroud Clearance Effect 8

6 Brush Seal installation 8

7 Engine Self-Sustaining Temperature and Speed Prediction 9 

k 8 Start Transient Cycle for First Ceramic Engine Build SIN 002C 10

9 Performance Rating Stations 11

10 Impeller Blade Loading-Hub 13

11 Blade Loading-Mid-Passage 14 

12 Impeller Blade Loading-Shroud 15 

13 Diffusion Flame Combustor ignition Performance 16 

14 Simplex Mod iI Fuel Nozzle (Film Cooled) 17 

15 Simplex Fuel Nozzle (Delevan Corporation) 17

16 Cooled Regenerator Seal Schematic, Phase 4 18

17 Regenerator Inboard (HOT) Seal Crossarm Temperature 18

18 AGT Regenerator Seal Leakage 18

19 AGT Regenerator Core Torque 19

20 Leakage and Sensitivity Improvements of Phase V Seals 19

21 Regenerator Seal Mechanical Load 19

22 Regenerator Seal Leakage 20

23 Regenerator Drive Torque 21

24

25

AGT Hot Regenerator Rig

RCG Coated Machine HTP

22

and Insulation From Lockheed 25

26 AGT101 Insulation Tzst Rig 26

27 Transition Duct and Baffle Screening Rig With Previous (top) and

Revised (bottom) Insulation Configurations 29 

28 Turbine Shroud/Turbine Stator/Turbine Backshroud Screening Rig 

With Previous (top) and Revised (bottom) Insulation Configuration 29 

29 Fracture Region 30 

30 Simulated Development Engine Start Transient 31 

31 Typical TIT Trace at Idle 31

32 Low Pressure Regenerator Inlet Temperature Versus Cycle Time 31 

33 Vacuum Formed Insulation Coating Degradation 32

34 Acoustic Emission Trace, Build 9 34

35 Turbine Shroud Fracture 35

36 Simulated Vibration Test for Outer Diffuser Housing to Shroud 36

37 Stock Removed Front Flow Separator Housing Platform to Provide

Axial Seal 37

38 Inner Diffuser Housing Fracture (Structures Pig Build 10) 39

39 Brush Seal Installation 41

40 AGT Foil TC Locations 4

41 AGT Inner Foil TC Locations 42

42

43

AGT Outer Foil TC Locations

Foil Instrumentation

4

43 

VI
1

s.

{ { LIST OF FIGURES (Contd)

i Figure Title

s

44 Hydrodynamic Fluid Film Trust Bearing Installation

K j 45 Pivoted Pad Air Bearing Installed in Engine

46 Pivoted Pad Bearing - Additional Features

i 47 As-Molded Turbine Shroud

48 Green Machined Turbine Shroud

t ,

to I

ri`i l

.^ I

Pa 

4

4

4

5

5
Table Title Pa

viii

LIST OF TABLES

SIN 001 Rotor Dynamic Summary 

Geometric Design Summary 1

Aerodynamic Design Summary 1

AFT101 Component and Material Summary 2

Summary of AGT Ceramic Material Characterization at Garrett 2

Thermal Screening Summary 2

Rig Assembly Ceramic Components 3

Development Engine Static Structural Hardware 3

Development Engine Static Structural Hardware 3

Ceramic Rotors Received From ACC 4

Flexure Strength of Test Bars Cut From Fully Processed ACC

Rotors at Room Temperature and 2200E 4

Summary of Brush Seal Steady-Steady Power Consumption at

Maximum Speed (1000p000 rpm) 4

1

2

3

4

5

8

7

8

9

10

11

12
1.0 SUMMARY

This report describes progress and work

performed by the Garrett/Ford team to develop an Advanced Gas Turbine (AG,r) engines

for automotive applications, during the period

July through December 1983. This work was

performed for the Department of Energy

ender NASA Contract DEN3-167. This is the

eighth In a series of semi-annual reports. Work

performed during the first seven periods (References 1 through 7) initiated design and analysis, ceramic development component testing,

and test bed evaluation.

Project effort conducted under this contract is part of the DOE* Gas Turbine Highway Vehicle System Program. This program is

oriented at providing the United States automotive industry the high-risk long-range technology necessary to produce gas turbine

engines for automobiles with reduced fuel consumption and reduced environmental Impact.

It is Intended that technology resulting from

this program reach the marketplace by the

early 1990s.

The advanced automotive gas turbine,

when Installed in a Ford vehicle (3000 pounds

inertia weight), will provide:

A CFDC fuel economy of 42.8 miles per

gallon based on Environmental Protection

Agency (EPA) test procedures and Diesel

No. 2 fuel. The AGT-powered vehicle will

substantially give the same overall vehicle

driveability and performance as a comparable production vehicle powered by a conventional spark-ignition powertrain system

o Emissions less than federal standards

o Ability to use a variety of fuels

*A list of abbreviations and acronyms is presented in Appendix D, herein.

1.1 Power Section Development

a Rotor dynamic Instability Investigatio

continued on engines SIN 001 and 003. Seve

forward ball bearing hydraulic mount confi

rations were tested with little effect. F

bearing parameters such as stiffness, foil nu

ber, load capacity and sway space we

changed with some benefits noted. init

investigations Into aerodynamic influen

were evaluated and a shaft damper system w

tested with marginal results.

Trial assembly of SIN 002 ceramic eng

was Initiated and testing plans and procedu

established.

1.2 Compressor Development

Impeller design activities have been co

pleted on the straight line element (SLE) bla

definition to address near-net-shape powd

metal die forging. Performance character

tics of the Baseline Test 2A impeller w

closely preserved. v Duplication of the Test 

impeller exit blade angle could not be fu

accommodated using SLE methodology (50

degree baseline, 47.97 degree SLE). T

lower exit blade angle gives rise to a low

slip factor and slightly higher work for t

same tip diameter. Therefore, tip radius w

reduced 0.016 inch to compensate for t

reduction in average exit blade angle. A

other salient design features w

satisfactorily preserved.

1.3 Turbine Development

The modified blading design has be

released to the subcontractors for tooling p

curement. No other activity was address

during this reporting period.

1.4 Combustor Development

Developmental testing of the diffusi

flame combustor (DFC) for initial use in t
SIN 002 2100 O F ceramic structures engine was

completed. Combustor wall temperatures

were recorded at idle and maximum power

conditions, and the combustor pattern ftfctor

was within acceptable limits.

A natural gas slave preheater was designed

and fabricated, while the nonvitlated preheater

was repaired.

A film cooled version of the Delavan slmplex nozzle was received and is being readied

for test.

1.5 Regenirator Development

Samples of a new rectangular matrix (1100

cell/in 2 ) were received from NGK, along with

the first full size core. Modulus of rupture

(MOR) is equivalent to the original thick wall

Isosceles triangular structure. In addition,

three Corning thinwall sinusoidal wrapped

cores also were received.

Hot regenerator rig testing of the Phase IV

seal was accomplished. The main objective of

the Phase IV design was to maintain the leakage characteristics of the Phase III while reducing the drive torque requirements. Three

different combinations of the Phase IV seal

design were evaluated. The best of these then

was selected for evaluation at various build

clearances to determine the effect of diaphragm clearance on leakage and drive torque.

Based on test data from Phase IV, initial

fabrication of Phase V seals was accomplished. Preliminary static seal rig testing

showed a significant reduction in leakage and

sensitivity to stack height. In addition, the

drive torque requirements were reducedSeals currently are being made available for

hot regenerator rig testing.

1.6 Ceramic Development

Ceramic screening tests were co

qualifying components for structures 

ing at 20000F. Two complete sets of 

static structures were qualified fo

testing. The components successfully 

minimum of 7 simulated engine sta

shutdown transients to 2000 0F. A tot

hours and 31 minutes were accumulate

this reporting period in the structures r

Seven rotors fabricated by ACC (8

Y2O2, 4-percent Al2O3) were sintere

this reporting period (four by Ford a

by ACC). Three rotors have passe

Inspection and are being machined 

testing. Two rotors were sectioned 

bar evaluation with results indicating 

at room temperature and 54 ksi at 2

Three rotors were delivered to ASEA-

for glass encapsulation and HIP expe

Densities ranged from 95-99 percent 

cal. Although these rotors were not 

ered good quality (visual, bladefill, 

rotor was selected for spin test.

1.7 Rotor DynamIes/FoB Bearing

Development

Effort continued on rotor dynamic

opment in support of resolving the 

chronous motion noted during engine 

Activities have included screening fo

ings for engine test, evaluation of 

damper, and Initiating a thorough 

mapping of the test rig and engine 

environment. In addition, alternate 

configurations are being investigat

active basis.

^^ -
2.0 INTRODUCTION

This report Is the eighth In a series of

Semi-annual Technical Summary Reports for

the Advanced Gas Turbine (ACT) Technology

Development Project, authorized under NASA

Contract DEN3-187 and sponsored by the Department of Energy (DOE). This report has

been prepared by The Garrett Turbine Engine

Company (hereinafter referred to as Garrett),

a Division of The Garrett Corporation, and

Includes information provided by Ford Motor

Company, the Carborundum Company, and

AiResearch Casting Company. The project is

administered by Mr. Roger Palmer, Project

Manager, NASA-Lewis Research Center,

Cleveland, Ohio. This report presents plans

and progress from July 1983 through December 1983.

Project effort conducted under this contract is part of the DOE Gas Turbine Highway

Vehicle System Program. This program is

oriented at providing the United States automotive Industry the high risk, long range technology necessary to produce gas turbine engines for automobiles that will have reduced

fuel consumption and reduced environmental

Impact, It is intended that technology resulting from this program be capable of reaching

the marketplace by the early 1990s.

The advanced automotive gas turbine,

when Installed In a Ford vehicle (3000 pounds

Inertia weight) would provide:

A CFDC fuel economy of 42.8 miles per

gallon based on Environmental Protection

Agency (EPA) test procedures and Diesel

No. 2 fuel. The AGT-powered vehicle shall

give substantially the same overall vehicle

driveability and performance as a comparable production vehicle powered by a

conventional spark-ignition powertrain system

o Emissions less than federal standards

o Ability to use variety of fuels

The Garrett/Ford Advanced Automot

Gas Turbine has been designated the AGT10

The program is oriented toward develop

the long range high risk technology of 

AGT101 gas turbine such that the auto ind

try can carry that technology forward to p

duction in the 1990s. Emphasis on cerami

gas bearings, low emission combustion a

Improved component performance domina

the effort. The AGT101 gas turbine is be

used as a test bed in which to develop th

technologies.

The program, as currently scheduled, 

depicted in Figure 1. The program continu

techology work through FY85, culminating 

the demonstration of the original goals 

engine specific fuel consumption, power o

put, and emissions. In addition, the viabi

of ceramics will have been demonstrated 

the AGT101 test beds, and the potential 

economically producing the ceramic parts 

automotive production quantities will ha

been assessed. When these goals are achiev

Ford will be in a position to Initiate t

production process without Government s

port, through the typical preproduction ta

which then could lead to production in 

1990s.

The primary technology challenge in 

program continues to be the development 

the meramic components and related high p

formance gas turbine aerothermodynam

components for the AGT101. The AGT101 

nominally a 100 shp engine, capable of spee

to 100,000 rpm and operating at turbine in

temperatures (TIT) to 2500 O F with a speci

fuel consumption level of 0.3 over much of 

operating range.

This report reviews the power secti

(metal and ceramic engine) effort conduc

to date, followed by a review of the co

ponent/ceramic technology development. A

pendices include reports of progress fro

Ford, AlResearch Casting Company, and 

Carborundum Company.
FISCAL YEAR

80 81 02 83 84 1 85 j 80 87 88 89

GOVERNMENT MILESTONES A I A 2 JA3,4 5

CERAMIC DEVELOPMENT ASSESSMENT 0 PROOUCIDILITY

STRUCTURES A 2100°F STRUCTURES

TURBINE 2500°F TURBINE

READY FOR TEST

REGENERATOR DEVELOPMENT

COMPONENT DEVELOPMENT

CHARACTERIZE

POWER SECTION 1800°F ENGINE

ALL CERAMIC 1

0 SHP

P I

ENGINE CHARACTER

DEVELOPMENT

,--—0.30 S CERAMIC

EMISSIONS I ENGINE

POWERTRAIN IST NGINE 1ST CERAMIC

DEVELOPMENT RUN PARTS 0 ^^ 50 MP

DEM

PRODUCTION ENGINEERING 42,8 MPG DEMO

AND MANUFALTURING

^^

_ _

DEVELOPMENT

GOVERNMENT L DESIGN REVIEW 4, INITIATE ENGINE TEST WITH CERAMIC ROTOR

MILESTONE'S 2, CHARACTERIZE ENGINE — BUILD 1 5. CHARACTERIZE ALL CERAMIC ENGINE

3. CHARACTERIZE ENGINE WITH CERAMIC STATICS

Figure 1. AGT101 Program Schedule.

4

AV ztkep,
3.0 POWER SECTION DEVELOPMENT

Rotor dynamic instability testing continued

on engine SINE; 001 and 003. Several forward

ball bearing hydraulic mount configurations

were tested with little effect. Changes were

made in the foil bearing parameters such as

stiffness, load capacity, foil number, and sway

space with some benefits noted. Aerodynamic

Influences were Investigated along with a

shaft damper system.

Trial assembly of SIN 002 ceramic engine

was initiated and plans prepared for Initial

testing during the next reporting period.

3.1 Rotor Dynamic Development

Rotor dynamic development to increase

stability continued through this reporting perled. This effort has included changes to the

forwrit i -t.01 bearing mounting, Increasing foil

bear'r:g stiffness by changing foil thickness,

toil. dumber and bearing sway space; and by

adding shaft dampers. In addition, some diagnostic testing was conducted to determine

possible sources of dynamic excitation. Engine SIN 003, the primary rotor dynamics test

bed, was tested 22 times and accumulated 8.7

hours run time and 67 starts. Engine SIN 001

was tested seven times and accumulated 7.2

hours run time and 11 starts. Some of these

tests were terminated because of synchronous

motion. However, during most of the tests the

rotating group exhibited a subsynchronous conical motion. This motion, depicted in Figure

2, has not damaged engine hardware, except

for occasional foil bearing distress, but the

relatively large amplitudes (1-4 mil motion at

the turbine end) have limited engine speed

between 58, 000 and 96 , 000 rpm depending on

test configuration. The subsynchronous motion is a forward whirl with a frequency range

of 55 to 105-Hertz, which approximates the

first critical frequency. This conical motion

has its maximum displacement at the turbine

end with the node occurring at the ball bear-,

ing.

55.105 Nt

.^-..-+_

OIL

AIR LUBRICATED

109HICATEO .1

FOIL BEARI NG

BEARING (HYDRAULIC

Figure 2, Rotor Exhibits Subsynchronous

Conical Motion Which Limits Engine Spee

The foil bearing stiffness was Increase

from 1000 to 5500 pounds/inch by changing th

foil number from 7 to 6 and the foil thickne

from 0.006 to 0.007 inches. The initial test 

this configuration attained a speed of 96,00

rpm; however, subsequent builds deteriorate

In dynamic stability.

To increase rotor damping, Engine SIN 00

was configured with three different hydrauli

mount configurations for the forward bal

bearing. Testing of these configurations show

ed little promise compared to the baselin

engine. (Table 1).

A major change was made in the fo

bearing by installing a relatively low stiffnes

(1500 pounds/inch at 0.006 Inch sway space*

bearing with very high load capacity. The loa

capacity was meas+.Fred to be 57 pounds com

pared to 10 pounds for the 5500 pounds/inc

bearing.

The first test with this configuratio

achieved a speed of 76,000 rpm, a 25-percen

increase from the previous test with the low

load capacity bearing.

Aerodynamic clearances were tested i

two of the five areas shown in Figure 3.

'Diametral clearance, bearing ID (minus) shaf

OD.

& VY3 1wi:. 1 I
TAA-PLE 1. SIN 001 ROTOR DYNAMIC SUMMARY.

thiud 10 11 12 13 14 15 

Thrust Hydraulic Compound Dutton Ring Compound Hydraulic Hyd

Denring Mount Parallel lHaslomer Elastomer Parallel Mount Mo

Standard Mount (dry) Mount (dry) Mount Standard Standard Sta

Pon a roll 6 fall 6 roil 6 roil 6 roil 7 roll 7 

Hearing springless springless springless springless springless L.A. type L.A

0.0088 S.S. 0.0088 S.S. 0.0088 B.S. 0.008B S.S. 0.0088 S.S. 01006 S.S. 0.00

Oearbox Quill Quill Quill Quill Close Quill Q

Coupled

Max 71.0 66 70.5 6BA 70.2 54.7 

Speed (Itrpin) (Unloaded (Unloaded) (Unloaded) (Unloaded) (Unloaded (Unloaded) (Unlo

76.5

(Loaded)

Vibration 1.3 at 96 IN 1.4 at 100 liz 1.4 at 100 liz 1.5 at 104 Ilz 1.24 at 105 lir. 1.2 at 76 3.5 

at Shut Down (Unloaded)

0.3 at Ins

(Loaded)

The bearing housing clearance (clearance 3

In Figure 3) was Increased from 0.0085 inch

cylindrical to 0.01.45 grooved as shown in

Figure 4. This clearance was later increased

to 0.040 inch cylindrical. No significant dynamic effect was noted due to changes in this

clearance.

The compressor backface clearance (number 4 in Figure 3) nlso was changed to determine Its effect on rotor dynamics. This clearance was changed from 0.024 to 0.054 and

0.079 Inch ciearance. The instability whirl

frequency increased with each increase in

clearance. The relationship is plotted in Figure 5. With the 0.079 inch clearance the

engine was run to 85,000 rpm. There is an

apparent Inconsistency between the significant

increase in frequency without a corresponding

Increase in stability. This inconsistency will

be investigated.

A brush seal used in some gas turbine

engine applications to replace a labyrinth seal

was manufactured to a size that coul

installed next to the foil bearing (see Fi

6)1 The brush seal was configured to Inte

with the shaft by 0.020 inch (diametral). 

would Increase the frictional forces 

inherent damping without adding signifi

stiffness or excessive power loss to the 

tem.

The Introduction of the brush seal 

coupled with decreasing the sway space in 

foil bearing. The foil bearing was teste

0.0084 Inch sway space as a baseline prio

adding the brush seal. Engine speed 

increased from 62,000 rpm to 84,000-94

rpm by adding the brush seal. Sway space 

decreased to 0.0064 inch and finally to 0.0

inch with the brush seal. No additio

benefits were noted by decreasing the s

space. Whether the improvements in stab

with the brush seal were due to added dam

or the thermal reduction of sway space In 

foil bearing through additional heat genera
FOIL BEARING OIL MOUNT GEAR

CLEARANCES

®I TURBINE BACNSHAOUO U COMPRESSOR BACHFACE

®2 TURBINE SHROUD ®5 COMPRESSOR SHROUD

BEARING HOUSING

Figure 3. Rotor/Bearing System Clearances.

by the brush seal adjacent to the foil bearing

Is not clear. However, the brush seal has

exhibited significant wear during test which

would diminish its effect with time, and thus,

it appears, that a brush seal is not a viable

solution for stabilizing the rotor/bee.ring syste m.

Planned development in rotor dynamics for

the next reporting period includes; experimentally mapping the thermal environment of

the foil bearing, completing the Investigation

of clearance effects, adding damping with

structural dampers and a hydrodynamic thrust

bearing.

3.2 Ceramic RnEtine Development

Trial build preparations for the firs

2100 O F engine containing a full compliment o

ceramic structures, was completed in October

1983.

Two trial assemblies of the SIN 002

ceramic engine were completed and a total

engine leak check was made to establish the

estimated self-sustaining temperature of the

unit (Figure 7). The analysis accounted for the

measured static leakage, rotor clearance

effects and the hydraulic loader parasitic drag

as a function of engine speed.

a A- 4^l:-... .-'
ti.YLl IpOYKI

. ^ I

I

IYU 11

tK1Y.ww /

A

t

\ IWI \ ru

\ twYO(Iw

I/IY IILt

KN.Y.

YOKKI

Figure 4. Configuration Differences.

20 40 60 80

8LEASANCE, MILS

Figure 5. Compressor Backshroud Clearance

Effect.

The primary purpose of the Build 1 test is

to subject the first AGT101 ceramic engine

130

120

r

J 110

_ x

y W

100

z LL

90

configuration to a thermal cycle limite

2100 O F TIT and 65,000 rpm rotor speed. 

engine will be operated along a contro

closed-loop turbine inlet temperature sched

Figure 6. Brush Seal installation.

Figure 8 gives a description of the 

transient showing engine light-off to 100

(on the starter) and maintaining that temp

ture for ten minutes at idle speed, then ra

ing temperature up to 2100 O F ( approxim

42 to 430F/minute). At approxima

1750 0F, estimated engine self-sustaining 

perature at idle speed, the starter assist 

be removed, and the engine will be loade

achieve a 2100 O F TIT. This temperature 

be maintained for three minutes prior t

ducing thr, engine load, and thereby decrea

TIT along an identical downward ramp u

all load is removed. Fuel flow wil

reduced to further drop TiT. At a minim

speed of 45,000 rpm, the engine will be 

down.

With the completion of the two trial bu

engine leak cheek, and analysis, the final b

and testing will be initiated during the 

reporting period.

8
__ innn 58,000 RPM

5.0 ' T43 WITH 65 LB/IN BRAG FROM

HYDRAULIC LOADER

4

,0 WITH LOADER 0 

3 1701 0

s

3.0 0

3E 60,000 RPM 51,000 52,000

53,000 ov,uu

0

0

Wi

1,0

0,0

WITHOUT LOADER

COMPUTER MODEL DATA

^-^^-• ESTIMATED TEST CART AND

ENGINE SHAFT HORSEPOWER

LOSSES

- 27% SYSTEM LEAKAGE

Figure 7. Engine Self-Sustaining Temperature and Speed Prediction.

9
F

10

t

i

START TRANSIENT CYCLE FOR IST•CERAMIC ENGINE

3

21 ---- — 21

— — — — I MIN

20

O IB `

16 ^! rq'\ BUAHER SHUTDOWN AT NGG 5 45,000 

14 1r^^ qq^^y

W

o.

3.E'

12-\

\

u 10 AIRFLOWMAX = 10 LB/MIN

= Nrr, MAY = 65,000 RPM

Wx

m

2

START TRANSIENT TIME, MINUTES

Figure 8. Start Transient Cycle for First Ceramic Engine Build S IN 002C.
Figure 9. Performance Rating Stations.

4.0 COMPONENT/SUBSYSTEM DEVELOPMENT

i

Component/subsystem development activities during this reporting period were concentrated on supporting AGT101 (1600 oF and

2100 0F) engine development, ceramic development, combustion tests and hot regenerator

testing. Figure 9 shows the performance

rating stations for the ACT101 engine and

components.

The following sections discuss major efforts and accomplishments during this reporting period for each component/subsystem.

4.1 Compressor

Impeller redesign activities have b

completed on the straight line element 

blade definition to address near-net-sh

powder metal die forging. The basis o

redesign was to maintain the performa

levelo demonstrated during Test 2A (R

ence 6) while approximating the arbi

blade shape using straight line eleme

Table 2 shows a geometric comparison o

Test 2A Impeller and the SI.E impeller, 

1.0 AMBIENT

2.0 COMPRESOR INLET

QOV1

2.05 IMPELLER INLET

2.5 DIFFUSER INLET

3.0 DIFFUSER

DISCHARGE

3.05 DUCT COMMON

INSTRUMENTATION

PLANE IRIGSI

3.1 REGENERATOR HP

INLET

3.5 REGENERATOR HP

EXIT

3.6 COMBUSTOR INLET

4.0 COMBUSTOR EXIT,

TURBINE INLET

4.1 STATOR INLET

4.5 STATOR DISCHARGE

5.0 TURBINE ROTOR

EXIT

5.05 DIFFUSER EXIT

(RIGS)

5.07 DIFFUSER EXIT

BEND (RIGS)

6.1 REGENERATOR LP

INLET

5.5 REGENERATOR LP

EXIT

7.0 POWER SECTION

1 EXHAUST
TABLE 2. GEOMETRIC DESIGN SUMMARY

Test 2A SLE

Hub/Tip 0.4478 0.4478

Inlet Hub Radius (inch) 0.600 0.600

Inducer Sweep Angle 7.28 7.37

(cold), degrees

Splitter LE Sweep Angle -5.43 -2.95

(cold), degrees

Exit Radius , inch 2.198 2.102

Exit b-Width, Inch 0.1718 0.1718

Blade Number 12/24 12/24

(inlet/exit)

Average Exit Blade 50.71 47.97

Angle, degrees

Exit Rake Angle, degrees 0 0

Axial and Radial 0.003 0.003

Clearance , inch

Inlet Shroud Normal 0.015 0.015

Thickness , inch

Wet Hub Normal 0.025 0.025

Thickness ; inch

Exit Shroud Normal 0.015 (eat) 0.014

Thickness , inch

Exit Hub Normal 0.052 (eat) 0.052

Thickness , inch

Average Exit Normal 0.026 (eat) 0.030

Thickness , inch

Vaneless Space Ratio 1.0751 1.0830

Diffuser Inlet Air Angles, 73.09 (est) 72.87

degrees

Diffuser inlet b-Width,

Inch 0.1664 0.1664

Diffuser Exit Radius, 3.233 3.233

Inch

Diffuser Exit b-Width, 0.134 0.134

Inch

Table 3 shows an aerodynamic comparison.

Duplication of the Test 2A impeller exit blade

angle distribution could not be fully

accommodated using SLE methodology. For

example, to keep the same hub and shroud

blade angles in the exit region resulted in an

average exit blade angle less than Test 2A

Impeller. This lower exit blade angle gives

rise to a lower slip factor and higher work for

the same tip diameter. Therefore, the tip

radius was reduced from 2.198 to 2.182

TABLE 3. AERODYNAMIC DESIGN

SUMMARY

Test 2A

Impeller

SLE

Impelle

P/pDuct, % -1.8 -1.8

P/PIGVP % From -0.55 -0i,55

Test Data

TT IN, R 544.7 544.7

PT IN, psis 14.350 14.350

Npgyg, rpm 1001000 100,000

WpgyS, Ibm/sec 0.855 0.855

Tip Speed, ft/sec 1918 1904

Total Temp Ratio 1.740 1.745

Efficiency, % 83.3 04.9

Specific Speed, rpm x 100 56.0 56.2

Mrelshroud 1.145 1.151

W2/W1 shroud 0.595 0.581

VI shroud 1.211 1.234

Vmean inlet

Average Deviation 6.12 6.52

degrees

Slip Factor 0.8970 0.8921

Q(CAPS) 0.9360 0.9337

Pressure Ratio 5.625 5.663

Wet Blockage 0.98 0.98

Exit Blockage 0.90 0.91

Inches to compensate for the reduction i

average exit blade angle from 50.71 t

47.97 degrees. Blade loadings are shown in Fig

ures 10 through 12. All other salient desig

features were satisfactorily perserved usin

the SLE technique.

4.2 Turbine

The modified blading design has been re

leased to the subcontractors for troling. N

other activity was addressed during this re

porting period.

4.3 Combustion

Development of the backup diffusion flam

combustor (DFC) was initiated for the SIN

002C ceramic engine. This combustor isaconven

tional film cooled, metal, design, and dis

12
G

0.70 O 111 BLADE

O AGT TEST 2A

0.60

0,60

°z

^^`J•

s 0.

0.40.E

a

n__

gWs

0.30

0.20

0.10

0 10 20 30 40 60 60 70 C.^ 90 

PERCENT MERIOIONAL DISTANCE

Figure 10. Impeller Blade Loading-Hub.

charge temperature rated at 21000F. It Is

similar to the combustor used in the metal

engine (1600oF TIT) except that the air orifices are proportioned to account for the different operating conditions.

Testing was conducted at idle and full load

conditions. At the full load condition, the

combustor maximum wall temperature was approximately 1800 O F and uniform, while combustor discharge temperature pattern factor

was within acceptable limits, 0.11. At idle,

wall temperatures also were uniform with a

maximum of 18000F.

Ignition data was obtained by rig simulation at 15-, 25 -1 35- and 45-percent speed points.

Figure 13 shows the ignition data. Ignition

fuel-air ratios linearly vary with engine speed

and are 0.012 at 15-percent speed and 0.007 at

45- percent speed.

Nozzle Development

Test facilities down-time resulted in 

program delays. The major contributing 

ponent was the second stage air pre-he

suppling the high temperature nonvitiate

to the test section. A natural gas slave 

heater was designed and fabricated whil

pairs were accomplished. The backup is 

sidered unsatisfactory for combustion te

wherein emissions are to be measured. H

ever, for other parameters of importance 

as nozzle integrity liner wall temperature

lean blowout limits, it Is a valid technique

A film cooled version of the lean 

Simplex fuel nozzle has been received 

Delavan (Figure 14). This nozzle is 

result of a heat transfer analysis to esta

sufficient air cooling techniques to supp

the onset of plugging as previously report

Reference 7.
0,00

0

0.80

x

x

U4

W 0.70

tN

21W

P.

0.60

n

0.50

0.40

0.30

q ART TEST 2A

1.00

-0:10.0

1.10

O SLE BLADE

40 50 60 70

PERCENT MERIDIONAL DISTANCE

Figure 11. blade Load ing-hfId-Passage.

A back-up fuel nozzle design was implemented in collaboration with Delavan Corporation. The objective of this design (shown in

Figure 15) was simplicity and compactness

so as to maximize the cooling capability and

minimize factors encouraging fuel coking. As

shown, the design replaces the center bodyswirler of the Simplex.

4.4 Regenerator Development

4.4.1 Ford Regenerator Development

4.4.1.1 Regenerator Cores

Samples of a new rectangular matrix with

1100 cells/in2 were received from NGK. The

14

. 1

modulus of rupture (MOR) is equivalent to 

original thick-wall isosceles triangular stru

ture. The first full-size core with this mat

geometry also was received during this repo

ing period. In addition, three Corning th

wall cores were received at Ford.

4.4.1.2 Regenerator Seals - Cooled

Diaphragms

To accommodate the higher operating te

peratures associated with the AGT10

(2500 0F) engine, the regenerator i

board (hot) seal crossarm requires diaphra

cooling. This design (Figure 16) ha

funnel incorporated in the crossarm end d

phragm, allowing cooling air to flow betwe
1.30

1.20

1.10

1.00

0.90

0

x

:E 0.80

W

s Od0

0,89

0.50

0.40

0.30

0

d

O SLE BLADE

q ACT TEST 2A

PERCENT MERIDIONAL DISTANCE

Figure 12. Impeller Blade Loading - Shroud.
0

s

fL

.J

0

0

FUEL: JP-4

AIR ASSIST AP 4.0 PSIG

• ^- 50o W

WN

CC

`. 400

0.014 \'^ 300 tW

0,012 s

0.010 200 y

0.006

0.006 NO LIGHT GHT

40

ENGINE SPEED, PERCENT

4.0 3.0 2.0 1,0

TIME TO LIGHT OFF, SECONDS

Figure 13. Diffusion Flame Combustor

Ignition Performance.

the middle and lower diaphragms. A transfer

tube at the corner allows the air to continue

through the high pressure side of the inner

periphery, exiting into the regenerator HP

discharge air stream through holes in the middle diaphragm.

The initial inboard cooled diaphragm regenerator seal was evaluated in the ceramic

structures rig at Garrett (Section 4.5.3 herein). Thermocouples were attached to both

halves of the crossarm shoe and middle diaphragm. The design objective is to keep the

diaphragm temperature below 1600 0F. The

results (Figure 17) indicated excellent

cooling at the crossarm outer extremities with

inadequate cooling air at the center hole region. The cooling passages and/or cooling flow

control devices require additional work in this

region to increase cooling flow.

To supplement the test hardware, a Ford/

Honeywell Computer System Program 

three-dimensional heat transfer analysis 

being utilized. A parametric study will 

conducted in an attempt to simulate the t

temperatures to guide future des

iterations.

4.4.1.3 Re r orator Seals - Performance

Development

The main objectives for the Phase IV s

design were to maintain the leakage char

teristics associated with the Phase IiI des

with a reduction In mechanical load charact

istics to reduce drive torque requiremen

Several modified versions of the Phase IV s

design were fabricated during this report

period for evaluation in the hot regenera

rig at Garrett. The intent of these s

combinations was to determine the effec

adjusting seal system loads on core operat

position and resulting leakage and drive torq

variations.

Three different combinations of the Ph

IV seal design were evaluated in the hot reg

erator rig. The best of these combinati

was then selected for evaluation at vario

build clearances to determine the effect 

diaphragm clearance on leakage and dr

torque.

These seals were evaluated for a to

diaphragm clearance variance of 0.052 

0.077 inch. The leakage level for the Phase 

seals (Figure 18) was equivalent to 

Phase III seals, Reference 7, even though 

diaphragm clearance was 0.012 to 0.037 i

higher. In addition, the Phase IV seal had 

cooling air funnel beneath the crossarm s

port diaphragm, which permits additonal le

age.

Drive torque requirements for the Phase 

seal design were significantly higher as Ill

trated on Figure 19. These data emph

size the need to incorporate a yoke at 

fixed roller location to allow Increased dr

torque capacity for the present seal desig

This requirement will be reviewed with Phas

designs now in progress.

16

'.m
COOLING AIR

FUEL_y

AIR ASSIST

JIM AGJACLMT TUIEI

CEMTEABODY

AND

AXIAL SWIALLA

FUEL AND AIR ASSIST

COOLING AIR

i

fLAME

f^

r

COOLING AIR OUT

COOLING AIR IN

AIR ASSIST

FUEL

COMBUSTOR

GOOLIMO AIR

Figure 14. Simplex Mod Q Fuel Nozzle (Film Cooled).

Figure 15. Simplex Fuel Nozzle (Delevan Corporation).

17
2000 1YMNL IODATION

+ - O IUAIIME INLET

O LORE INLET 1 1100

t

0 1N0E 135 a S61

4 DIAPHRAGM 162 A 331

1 1

1600

0 DIAPHRAGM 181 a SNI

l

r

1400

LL

1200

'/OIAINRAOMI ^

INIIIMIlO '76

^ 1600

j I \

CONTINUOUS AIM \ LP,

8 1 St 93 S/

AflAIN[

LOLLING AIR PAIN

\

35 O S8 WIN ^ HA^ ^^

w-. -MIONG `

1.0 LO

•^_ 3 DIAPHRAGM, I AM

t

WWII T1TIM + 

\

Figure 16. Cooled Regenerator Seal 200

Schematic, Phase 4. G 20 46 eo 10 Im

TIME, MINUTES

12

PHASE IV

NOVEMBER 83

CLEARANCE = 0.052. 0,077 Figure 17. Regenerator Inboard (HOT

10 Seal Crossarm Temperature.

PHASE I

Le

2E

APRIL 82 B. CLEARANCE = 0.050 INCH Bcsed on the test results for the Pha

m seal design, a Phase V design was initi

u

The primary design objectives for the Ph

8 seal configuration were to decrease le

and drive torque requirements. To accom

these objectives, the Phase V design fea

4 an Integrated crossarm dia phragm which 

W inates the inner secondary diaphragm req

2

In previous designs. A controlled test seq

^+^^ PHASE fll In the static seal rig indicated a signif

,PAIL B3

CLEARANCE = 0.1140 -0.050 INCH Portion of the total leakage occurs a

0 Inside and outside corners. In addition

0 10 20 30 40 50 60 Integrated crossarm diaphragm has a red

SEAL PRESSURE OIFFEREN 'iIAL (API, PEI lift angle, which should significantly r

the mechanical load characteristics and 

Figure 18. AGT Regenerator Seal Leakage. torque requirements.

18
PHASE IV

NOVEMBER 03

400 CLEARANCE = 0.087.0,077

PHASE III

APRIL 03

CLEARANCE _

300

Ei

p 200

s

h

W

0

v

100

CLEARANCE = 0.050

PHASE IV

PHASE IIIHX025 CX025 AVE

32

HX017JAVERAGE

28

24

Uj 20

o`e 16

12 PHASE V

w 4

1 CX012 CX01'

AVERA

HX026

0

0,270 0.275 0,280 0.285 0.280 0.205 0.30

SEAL WORKING HEIGHT. IN

Figure 20. Leakage and Sensitivity

improvements of Phase V Seals.

1800

1800

ICU

1200

m 1000

0

4

° 000

000

400

200

0

0 10 20 30 40 50

SEAL PRESSURE DIFFERENTIAL (AP). PSI

Figure 19. AGT Regenerator Core Torque.

The initial set of Phase V seals were fabricated for evaluation in the static seal rig.

This seal design demonstrated a signl°leant

reduction in leakage level and sensitivity to

diaphragm clearance (Figurre 20) when

compared to the Phase III and iV.

The mechanical load characteristics for

the Phase V seal also indicate a significant

reduction when compered to the Phase III and

IV configuration as shown on Figure 21.

Thus, the Phase V configuration exhibits

potential for reduced leakage and drive torque

eharacteristtcs. This set of seals will be

evaluated in the hot regenerator rig during the

next reporting period.

A new top plate for the static seal leakage

rig was designed and fabricated during this

report period. This plate has an opening in the

plexiglass portion of the low pressure side to

0 0.010 0.020 0.030 0,040 0.050 0

DIAPHRAGM CLEARANCE. IN

Figure 21. Regenerator Seal Mechanical 
.,

accommodate detection of leakage between

system components such as rubbing shoo, retainer and diapl^ragms.

Based on visual observation of coatings and

diaphragms of previous seals tested in the

AGT regenerator rig and engines, a significant

leakar,e path appeared to occur In the center

hole region. Consequently, definition of the

cover and flow separator housing deflection as

it effects seal pocket depth in this region is an

important criterion for design improvements.

4.4.2 Regenerator Development (Garrett)

The hot regenerator rig was assembled and

tested to evaluate the leakage characteristics

and drive torque requirements of Ford's Phase

IV regenerator seals.

Ford fabricated three sets of seals for test

evaluation:

o Baseline Phase IV seals

o Phase IV with increased inner peripheral

seal loading plus tapered thickness hot

crossarm shoe

o Phase IV with increased seal loading plus

welded seal diaphragms

Each of these seal sets were Installed and

tested in the hot regenerator rig under nominal operating conditions (T3.1 = 250017, T5.1

12000F).

The third seal set with welded diaphragms

exhibited such high seal loading resulting in

excessive drive torque and prohibited the measurement of useful data. In fact, while attempting to test these seals, the ring gears

were separated from two regenerator cores as

a result of drive torques in the 300 to 450

ft-lb range.

Successful tests were completed on the

baseline and tapered seal sets. The drive

torque and leakage characteristic for these

seals are shown on Figures 22 and 23, respectivel

PHASE IV — BASELINE

HX•021

CX•021

HOT-DYNAMIC

PHASE IV — TAPERED

OX-023

CX•022

NOT-DYNAMIC

16

T3, 1 - 250°F

14

T5. 1 ^ 1200° F

E 12 NREG 12 RPM

f

m

10

x

B

4

Y., 6 n

4

2

0

0 10 20 30 40 50 6

SEAL PRESSURE, PSIO

Figure 22. Regenerator Seal Leakage

The baseline seal set exhibited lower 

torque requirements and substantially hi

leakage than the tapered seal set. The dis

ity In seal performance is probably a resu

the higher seal stiffness of the tapered 

set.

Relative to the best of the earlier 

configurations neither of these seal sets 

hibited an improvement.

Instrumentation was added to this r

measure the variations in seal clearance a

regenerator seal inner periphery cros

positions. This instrumentation consisted 

set of Bently clearance probes mounted 

bracket anchored to the exhaust cover 

circle. The Bently targeted a "finger" fixe

20
NREO — 12 RPM

320

T3.1 — 2504F

280 T5,1 — 1200°F

240

mJ

J 206

O'

160

W

c 120 PHASE IV — BASELINE

+O^ HX•O21 CX•021

0

t;

^ 80 ^^ PHASE IV — TAPERED

= HX•023 CX•022

s 40

COLD BUILD POCKET 3.690 INCHES

0 10 20 30 40 50 60

SEAL PRESSURE. PSI6

Figure 23. Regenerator Drive Torque.

the regenerator shield. Another Bently targeted the flat land of the exhaust cover. This

system is shown in Figure 24. By comparing

these clearance measurements, taking into accourt thermal growth of the regenerator

shield, and the thermal effects on the Bently

calibrations the local variations In regenerator

pocket can be calculated.

The data from this clearance probe instrumentation was Inconclusive due to the lack of

Information on the thermal growth of the

regenerate- shield. Qualitatively however,

these data seemed to indicate an opening of

the inner peripheral regenerator pocket with

increased rig press-are.

This test will be repeated at a future date

with more comprehensive thermal instrumentation on the regenerator shield.

4.5 Ceramic

4.5.1 Materials

4.5.1.1 Ceramic Material Testing Summary

A summary of the material property results is presented in Table 4. Additionally, a

material characterization reference chart

indicating where additional information (gen

erated by Garrett), is presented in Table 5.

4.5.1.2 Turbine Diffuser/Insulation

Evaluation

As reported previclsly, (Reference 7), th

use of a fibrous insulation system as a portio

of the turbine diffuser design was stimulate

by results of the Babcock and Wilcox vacuum

formed 3000 material insulation in Builds 

and 10 of the structures rig. Results of tha

testing supported the ability of this type o

Insulation to withstand high temperature ga

velocities for short durations. However, sur

face erosion on the Insulation indicated that 

more durable system would be required fo

longer term exposure and higher gas veloci

ties. In pursuit of an improved insulatio

system, several samples of Lockheed High

Temperature Protection (HTP) were obtaine

for evaluation. The sample consisted of cylin

ders of sintered and machined 'nigh purity S10

and Al203 fibers. The samples were machined

to form cylinders with a 3.1-inch bore and a 3

inch length. As machined cylinders, and cylin

ders partially coated with a borosilieate glass

designated by NASA and Lockheed as reaction

cured glass (RCG), were provided by Lockheed

and shown in Figure 25.

Two samples, one uncoated and one coated

have been exposed to combustor discharge

gases as Illustrated in Figure 26. During thi

test, vitiated air at 2100 O F was directe

throucF the cylinder '-ore at 20 lb/min (ap

proxim ately 250 ft/sec) for 46 minutes. Thi

condition exceeded the 75 ft/see gas velocit

predicted for the turbine exhaust diffuse

dump region currently utilizing the Babcock

and Wilcox fibrous insulation.

Post test visual examination did not revea

any damage to the coated sample and only

minor surface erosion on the uncoated sample

2
BENTL

BRACRai

POCKET VARIATION

MEASUREMENT

Figure 24. AGT Hot Regenerator Rig.

22
TABLE C AGT101 COMPONENT AND MATERIAL SUMMARY

Quallllcatlon Bar Cenmie Cam went

Roam Tem erature I Elevated Tennneratum RoamTenuverAture I Elevalpt Tolpi nerAture

Supplier Material Process Condition -;6 74 M Population ug 4 M eF Population W9

0) M Population up 41 M eF I Population

ACC

Inner Diffuser RBSN Slip As Flrod 09,7 4,1 70 12.1 1011 2200 10 4.1%) 1 21 ••

Outer Dlllurer (11111,1104) Cut Longlludinally 5).2 5.) 10 46.3 )J 27 .-

Turbine Shroud Ground

Heat Treated 74,1 1.5 29

ACC

Stator RBSN Inleetlon AbFlred(l) 40.1 4.1 19 44.5 S,4 2200 23 2201 ..

(RBN 174) Molded

ACC

Rotor Sintered Slip Longitudlnally17 •• - - - •• 11717) 6,0 20 54 915 •- 10

S13N4 Calf Ground

(SNN 102)

Sintered In action Ao-Flred 49.2 6,9 30 10.9 7.6 1160 9 - •• -

5I 3N4 =olded 66.1 11.1 2000 70

67,7 10.1 2200 10

(SNN 122) 23.6 13.6 2700 12

Carborundum

Turbine Shroud, Sintered Injection As Fired 48.6 9.5 30 41.0 3.0 2100 10 55.0 17) 7,1 9 ••

Stator a-SIC Molded

Combustor Sintered Slip Longitudinally 49.4 1,1 )0 41.4 6,7 2500 10 57.0 7.) 9 ••

Baffle n-SIC Cut Ground

Traneltla, Sintered Isopressed Longitudinally 77.7 7,7 30 56,2 11.9 2700 10 -- -•

Duct, Region ..Sic Grand

Shield, Back.

shroud

Fad

Rotor SRBSN Slip Longitudinally 109.3 19.1 6 73.1 16,4 2200 6 - - •-

(RM.2) Cast Ground

Slat" RBSN Infection As Flred 45.1 9.2 39 47.1 7.7 2200 10 -- -- •• •• •• •• •-

Molded

NCK

Backshroud, Sintered Iwpresud LatRltudinally 17,4 IOJ 10 47.1 U,6 2000 7 -- -- •• •• -• •• •-

Transition S17N4 Grand

Duct (SN-30)

All test bars 0.250 x 0.121 Inch cross section unless poled, Ban tested in 4-point flexure, 1.50 Inch outer spm ud 0.75 Inch inner span. Cross head speed, 0.02

inchyminute

(I) Test bar cross section 0.51 X0.15 inch (1) 98.8 percent dome (51 As machined, longitudinally ground

(21 Test bar cross section 0.2 x 0,1 Inch (4) Characteristic strength, fill (6) Test bar section 0.276 x 0.1 inch

,

I

i

ThN erosion was judged a result of local

surface damage resulting from the machining

operation rather than the exposure conditions.

These preliminary results Indicate that coated

or uncoated HTP may be suitable for use in

the current AGT101 engine configuration and

that the RCG coated HTP may be suitable for

use in higher gas velocity locations. Procurement of additional test articles and additional testing will be pursued.

4.5.2 AGT101 Ceramic Component Thermal

Screening

Prior to qualification testing of AGT101

ceramic components in the static structures

rig, all ceramic parts with predicted hig

thermally induced stress are screened in su

assembly thermal screening rigs.

Thermal screening is intended to elimina

components with gross Internal defects and/

smaller defects located in regions of hig

bending or tensile stress. These lower quali

components will fracture during therm

screening allowing only the highest quali

parts to continue through qualification testin

and subsequent engine tests. The therm

screening rigs provide a screening test bed f

various components, configurations, and mat

rial changes and have an upper temperatu

limit of 21000F.
TABLE 5. SUMMARY OF AGT CERAMIC MATERIAL CHARACTERIZATION AT GARRE

KA

N4K 

AlResearch Caabng Co, Carbmundunl Co. among ford%rotort u. Ln Lp 

Retetion.51h1ered

Iteaction•Duided Sl )N4 Slivered $I 

INS, 51ntered SIC S,C LAS MIDSN IIIISN LAS

SL IM SC INS IM IF CF Chi IF Ilul SC , 161 II' 

Ihptlpd

911N-104 IIIIN.124 RDN-126 SSN.502 SSN•522 KK•01 KK-02 51V 8614 SNOO 

Flexure Sirniylh

Rwn1 Temperature 51 .2411 51 .251 5)•46 51.256 57.61 51 .266 51 .265 51 .764 56 54.26 52.68 SL

S7- 56.97 56 .99 57.59

56.96

Clrvulud Temp,

T 1 (1600.20007) SI.2)1 SI.156 SI.264 SI.M 54 .2) S6 S6 SIAS

T2 (72007) 51.24) SI.2S7 57.59 54.26 574,6

51.264

T S (7)007) 51.245 51 .251 51.256 52.61 SI-266 51463 5249 52.66

51.264

Transverse 51.246 51.255 52.56

Machined SI.277

Longitudinal SI-248 51.255 51.266 51.271 5)41 54 .23 54.26 SI.S 

Machined

Cut front S6 $2.67 57.49 

Components CCM6I 53-46

54

Post-Machining SI.246 52.61 52.59 54.25 

Oxidation 57 51.277

Oaldaticil

Gradient Furnace 54.10 $440

Dywunc 54.76

Durab hly ltig

Sires lluptum

Static, Air 56. 54.11 54.11

51.762

52.6)

Dyne nn c, 57.6) 52.65

Gat Fired

Interlace

r,onsideraliuns

Compatibility 5S-38 55-78 55-38 55-36 55 . 76 5548 55-)8 Test CCM62 CCM62 CCM62 CCM62 CCM62 CCM62 CCM92

Sliding Tests 52.74 52.7)

51.261

Cwting 52.76 52-78

Development 51.760

Shrink Fill

Ralchot Tests

Thermal Shock 54.75 54-)5

(Stator&)

Split Test (dolor)

Dladelea Rotor 53•46 52.65 52-65 cemal

Dfaded Rotor CCM62

55.75

• Tinted under NASA 3500•Mour Durability Program, Contract DEN347,

5C. Slip Cast

IM . InSecllon Molded

11' Isoprelsed

CI' Cold Pressed (Uniaxial)

SRDSN . Slnlered Reaction Derided SIIN4

Examples of Ileferencest

51 .245 : Page 745, Flat Semi-Annual Report

CCM62 • Paper preseeled at 1982 CCM

24
Figure 25. RCG Coated and Machined HTP Insulation From Lockheed.

A list of the AGT101 ceramic static structural components tested during this reporting

period are shown in Table 6. These tests have

successfully screened components to 2100OF

and have provided valuable data for stress

reduction design modifications.

During this reporting period, experimentation with improved screening rig insulation,

using vacuum formed alumina-silica fiber, was

conducted. The goal is to extend the life of

the screening rigs while duplicating, as closely

as possible, engine thermal conditions.

An improved insulation configuration for

the transition duct and combustor baffle

screening rig was successfully employed in 

December8 1983 test oft hesecomponents. I- ig

27 illustrates the old and new configuratio

It is anticipated that the life of this rig 

significantly extended.

The turbine shroud/turbine stator/turb

backshroud screening rig was likewise 

graded to a new insulation configuration

illustrated in Figure 28. The more effec

insulation and alteration of the flowpath 

felt to have contributed to higher shro

stresses, and subsequent fracture of turb

shrouds SIN 377 and SIN 374 on Decemb

and December 12, 1983 respectively ('fa

6). Review of SIN 216 is underway.

MY•97)64
THERMOCOUPLE

131

r,

WA 1

1

COMBUSTOR

4.5.3 Ceran

Build 7

Build 7 H

ceramic cc

screened in

mal and mec

final stages

loaded comb

were being

shield platfoi

26
TABLL 6. THERMAI. SCREENING SUMMARY

Date Component or Sub-Assembly SIN Mat'l Supplier TmELx,oP R

7/1/83 Inner Diffuser Housing 294 RBSN ACC 2000 

Outer Diffuser Housing 289 RBSN ACC 

7/27/83 Transition Duct 002 SSN NGK 2100 

Combustor Baffle 112 SASC CBO 

7/28/83 Transition Duct 111 SASC CBO 2100 

Combustor Baffle 111 SASC CBO 

8/1/83 Turbine Shroud (B-3 Design) 307 RBSN ACC 2100 

Turbine Stators (Segmented) Set 2 RBSN ACC 

Turbine Baekshroud 002 SSN NGK 

8/2/83 Turbine Shroud (B-3) 308 RBSN ACC 2100 

Turbine Stators (Segmented) Set 3 RBSN ACC 

Turbine Backshroud 105A SASC CBO 

8/3/83 Inner Diffuser Housing 309 RBSN ACC 2000 

Outer Diffuser Housing 300 RBSN ACC 

Ceramic Bolt Assembly 007 HPSN Norton 

008 — — 

009 — — 

Ceramic Rocker Assembly 007 SASC CBO 

008 — — 

009 — — 

8/9103 Inner Diffuser Housing 311 RBSN ACC 2000 

Outer Diffuser Housing 297 RBSN ACC 

Ceramic Rocker Assembly 004 SASC CBO 

005 — — 

006 — — 

10/4/83 Turbine Shroud (B-3) 354 RBSN ACC 2100 

Turbine Stators (Segmented) Set 4 SASC OBO 

Turbine Baekshroud 104 SASC CBO 

12/2/83 Inner Diffuser Housing 318 RBSN ACC 2000 

Outer Diffuser Housing 334 RBSN ACC 

Ceramic Bolt Assembly 013 HPSN Norton 

014 — — 

015 — — 
TABLE 6, THERMAL SCREENING SUMMARY (Contd)

Date Component or Sub-Assembly SIN Mat'1 Supplier Tmax,oF R

12/5/83 Turbine Shroud (B-3) 377 RBSN ACC 2100 Fr

12/8/83 Transition Duet 109 SASC CBO 2100 

Combustor Baffle 122 SASC CBO 

12/12/83 Turbine Shroud (B-3) 374 RBSN ACC 2100 Fr

12/13/83 inner Diffuser Housing 317 RBSN ACC 2000 

Outer Diffuser Housing 364 RBSN ACC 

Build 8

On August 31, 1983 the AGT101 Ceramic

Static Structures Rig successfully qualified a

completesetof development engine staticstruetural ceramic components through seven simulated engine start transients to 2000 0F. A

statistical summary of the test is shown

below:

• Total Light-Offs 14

• Time at 1200 O F 1 Hr 48 Min

• Time at 1500 O F 44 Min

• Time at 1800 O F 40 Min

• Time at 2000 1F 1 Hr 26 Min

• Transient Time 1 Hr 3 Min

o Total Rig Time 5 Hrs 45 Min

The rig assembly included seventy-eight

ceramic components fabricated from three

basic materials; silicon nitride, silicon carbide,

and lithium aluminum silicate (Table 7).,

Six fabrication processes were utilized representing the fabrication techniques and capabilities of six ceramic suppliers.

The simulated development engine start

transient followed for this test is shown in

Figure 30. Engine idle conditions for HP and

LP airflows were maintained at 10 lb/min with a

differential pressure of 5 psid. Figure 31

shows a typical T4, 1 trace during the test and

Figure 32 depicts the LP regenerator inlet

temperature (T5 , 1) as a function of cycle

time.

Rig testing was terminated during 

eighth start transient due to excessive 

pressure to low pressure internal leakage. 

rig was disassembled and inspected for com

nent damage.

Minor chipping was noted on the follo

components: combustor baffle strut, ecce

spacers, flow separator housing ID seal 

and T4.1 (TIT) thermocouple load spac

None of the noted chipping was a resu

material interface sticking.

The regenerator inner seal (hot side s

had temperature instrumentation installe

monitor both seal diaphragm and subst

temperatures. The excessive leakage 

terminated the test was due to collapsed 

phragms on the inner seal from over-heat

The inner seal Incorporated Ford's initia

cooled diaphragm design. Inspection of 

failed seal indicated partial blockage of 

cooling air passage from the installed ins

mentation. Ford's heat transfer analysis sh

that the seal should properly function when 

cooling flow is unobstructed.

The vacuum formed ceramic fiber ins

tion used to form the diffuser discharge f

path survived the test with minor radial cr

(Figure 33) through the flowpath coating l

and substrate. The surface coating appea

have cracked and spelled off the substrat

the highest velocity region immedia

downstream of the diffuser discharge. Ra

28
e

H

Figure 27. Transition Duct and Baffle

Screening Rig With Previous (top) and

Revised (bottom) Insulation Configurations.

Figure 28. Turbine Shroud/Turbine Sta

Turbine Backshroud Screening Rig With

Previous (top) and Revised (bottom)

Insulation Configuration.

I

+i 
e

Figure 29. Fracture Region.

cracking in the substrate was evident I

high velocity region Immediately d

stream of the diffuser discharge, and ap

to be related to the vacuum forming fab

tion process. Large voids are evident be

the "plate-like" layers of material 

weaken the Insulation mechanical prope

improved fabrication techniques by the 

plier are expected to alleviate the poor q

of the insulation preforms.

Turbine shroud alignment is of param

Importance in maintaining proper turbine 

running clearance within close tolera

The ceramic rocker/eccentric assembly 

cessfully maintained cold assembly ru

dimensions of 0.0015 inches Total Indi

Reading (TIR) through the cyclic testing.

TABLE 7. RiC ASSEMBLY CERAMIC COMPONENTS

Throe Materials, Six Fabrication Processes, Six Suppliers

In B/N8

Component Name SIN Material Source Quantity Design Configuration

Regenerator Shield 104 SASC CBO 1 A-1

Regenerator Shield Piston Ring 001, 002 RSSC Pura Carbon 2 A-1

Plow Separator, Ilousing 13 LAS Corning 1 A-2 (3-T4,1 Probes)

Regenerator Core MAS NOK 1 Cooled Thick Wall

Transition Duet 111 SASC CBO I A-3 (3-T4,1 Probes)

Transition Duct T4 ,1 Rushing 001, 002, 003 SASC coo 3 A-1

T4 ,t Inner Seal (Female) 001, 002, 003 LAS Corning 3 A-t

T4,1 Inner Seal (Mole) 001, 002, 003 LAS Corning 3 A-1

T4 ,1 Inner Seal Spacer 001, 002, 003 LAS Corning 3 A-1

T4 ,1 Inner• Seal Load Spacer 001, 002, 003 LAS Corning 3 A-1

T4 ,1 Outer Seal(Female) 001-004 LAS Corning 4 A-1

T4 , 1 Outer Sent (Mole) 001-004 LAS Corning 4 A-1

Combustor Baffle 112 SASC CDO 1 A-2 (0.200 Wall-Unifor

Turbine Backshroud 102 SSN NOK I A-1

Turbine Stators (Seg.) Set 02 RDSN ACC 19 A-1

Turbine Shroud 308 RBSN ACC 1 8-3

'turbine Shroud I.D. Seal 0.001 RBSN ACC 1 A-1

Turbine Shroud Wave Spring 001 RBSN ACC 1 A-1

Turbine Shroud O.D. Seal 001 RBSN ACC 1 A-1

Outer Diffuser Housing 300 RBSN ACC 1 A-3 (Dump Section)

Inner Diffuser Housing 311 RBSN ACC 1 B-2

Inner Diffuser Load Spacer 001, 002, 003 LAS Corning 3 A-1

Bolt Assembly 004, 005,006 I1PSN Norton 3 A-1

Rocker 004, 005, 006 SASC CBO 3 A-1

Eccentric 004, 005, 006 SASC CBO 3 A-1

Contract Washer (Upper) 004, 005, 006 HPSN Norton 3 A-2 (0.150 Thickness)

Contract Washer (Lower) 004, 005, 006 HPSN Norio" 3 A-2 (0.150 Thickness)

Crowned Washer 004, 005, 006 IIPSN Norton 3 A-1

30

w 
2000

10 MIN

1800 _ ` — — _ 4 MIN

1

W

^y

o

1500 --- — — 

4 MIN °'

h

6 MIN ='

s 1200

d AIRFLOW 10 LB/MIN

W 1000

E Wh

1!J

16 MINI

a SHUTDOWN

a AIRFLOW REDUCED TO 5 LR/MIN

2D0

6 10 I6 20 26 30

START TRANSIENT TIME, MIN

Figure 30. Simulated Development Engine Start Transient.

0

Q

6

g

N

n •I-Z-4#

PROSE NUMBERS I AND 2

SO• F SPREAD

m ^0 10 20 30 40 50 SO 70

TIME, MINUTES

Figure 31. Typical TIT Trace at Idle.

.w

ISO

TB.I ILP REGENERATOR INLETI

_ ...

.V I850-F AND 1

12

2

0

W

40

0

0 10 20 30 40 50 SO 7

TIME, MINUTES

Figure 32. Low Pressure Regenerator

Inlet Temperature Versus Cycle Time.

0

Q

d

ISIN

3
Oi?jGNIaL

OF POOR QUALII Y

6. 1

to 0

Figure 33. Vacuum Formed Insulation Coating Degradation.

F

{

J

' 32

MI'-93367 
i

Test Procedure

Build 9

On September 28, 1983 the second complete set of development engine static structural hardware (Table 8) was tested to 2000OF

using the identical start transient of Build By

Figure 30.

At two minutes into the second 200002

thermal transient the acoustic emission monitor picked up a continuous high energy output

from the number three bolt location. The

acoustic trace shown in Figure 34 shows the

RMS output saturated and a count rate

(counts/event) was observed in the 900-1000

range. Due to the high energy Indication the

test was terminated and the rig disassembled.

A statistic and summary of the test is as

follows:

o Total No. of Light-offs 

o Total time at 1200 O F 

o Total Time at 1500O F 

o Total Time at 1800 O F 

o Total Time at 2000 O F 

o Transient Time 20 Mins 

o Total Rlg Time 1 Hr, 

Upon disassembly, component ins

revealed a fractured turbine shroud and 

from the outer diameter of the outer 

near the second bolt location (7 o'cloc

tion). The inner and outer diffuser asse

spring loaded against the turbine shroud 

ting flange through the eccentric sp

this location. Eccentrics at the seco

third bolt locations were lightly "stuck

ther In the unloaded position due to ap

foreign material lodged between the ec

and the rocker during test. This un

TABLE B. DEVELOPMENT ENGINE STATIC STRUCTURAL HARDWARE

Three Materiels, Six Fabrication Processes, Six Suppliers

In B/N19)

Component Name SIN Material Source Quantity Design Configura

Regenerator Shield IDS SASC CBO 1 A-I

Regenerator Shield Piston Ring 003, 004 RSSC Pure Carbon 2 A-)

Plow Separator, Housing 12 LAS Corning I A2(3-T4.1 Probes)

Regenerator Core MAS NCH I Coaled Thick Wall

Transition Duct 102 SSN NOK 1 A-3 (3-T4,1 Probes)

Transition Duct T4,1 Bushing 004, 005, 006 SASC CUD 3 A-1

T4 , 1 Inner Seal (Nemale) 004, 005, 006 LAS Corning 3 A-I

Tq,1 Inner Seal (Male) 004, 005, 006 LAS Corning 3 A-0

T4 , 1 luncr Seal Spacer 004, 006, 006 LAS Corning 3 A-1

T4,1 Inner Seal Load Spacer 004, 005, 006 LAS Corning 3 A-I

T4,I Outer Seal (Female) 004, 005, 007 LAS Corning 4 A-1

T4,1 Outer Seal (Male) 004, 005, 007 LAS Corning 4 A-)

Combustor Baffle III SASC Clio 1 A-2 (0,200 Wall-Un

Turbine anekshroud 105A SASC CUO 1 A-1

Turbine Stators (Beg,) Set 03 RBSN ACC is A-1

Turbine Shroud 354 RBSN ACC 1 0-3

Turbine Shroud I.D. Seal 002 )ISSN ACC 1 A-1

Turbine Shroud Wave Spring 002 RBSN ACC I A-1

Turbine Shroud O.D. Seal LASS 001 RBSN ACC 1 A-1

Outer Diffuser Housing 297 RBSN ACC I A-3 (Dump Section)

Inner Diffuser Housing 309 RBSN ACC 1 B-2

Inner Diffuser Load Spacer 004, 005, 006 LAS Corning 3 A-1

Boll Assembly 007, 008, 009 HPSN Norton 3 A-1

Recker 007, 008, 009 HPSN Norton 3 A-1

Eccentric 007, 008, 009 HPSN Norton 3 A-1

Contract Washer (Upper) 007, 008, 009 IIPSN Norton 3 A-2 (0.150 Thicknes

Contract Washer (Lower) 007, 008, 009 HPSN Norton 3 A-2 (0.150 Thicknes

Crowned Washer 007, 008, 009 HPSN Norton 3 A-1
SATURATION:

MAX ACOUSTIC

ENERGY

SATURATION;

MAX ACOUSTI

ENERGY

ORIGfNAV PWV I `

I

OF POOR QUALITY

COUNTS/EVENT 

Figure 34. Acoustic Emission Trace, Build 9.

position can allow the outer diffuser to vibrate

against the turbine shroud due to recirculating

flow behind the outer diffuser with pressure

differential from diffuser Inlet to discharge as

the driver.

Fracture Analysis

The turbine shroud fractured at a surface

defect as indicated in Figure 35. The defect

was approximately 0.125 inch in depth.

Fracture of the turbine shroud occurred at

a time in the cycle when the analytically predicted thermal stress was less than 1 ksh

Since the shroud had survived a higher thermal

stress at 1200 O F (200 to 1200 OF transi

thermal stress was ruled out as the caus

fracture. Further, since the shroud had 

cessfully completed the first .cycle to 200

without a fracture indication a jafe assump

is that no interference was present,.

The one outstanding feature of the fr

ture was the unique acoustic signature, wh

gave the appearance of high energy vibra

between two major components. Since 

outer diffuser housing was "loose" in the s

due to the apparent sticking (FOLD at 

msmber two and three bolt location

vibration mode could conceivably be ex

Into the stack by the 10 lb/min airflow, and 

pressure differential across the part.

34
BOLT LOCATION NO. 2

BOLT LOCATION NO. I

i

LT LOCATION

NO. 3 I -^ rL —

DEFECT LOCATION

Figure 35. Turbine Shroud Fracture.

On the basis of outer diffuser to turbine

shroud vibration a test was conducted on the

inner and outer diffuser thermal screening rig

In which the ODH was deliberately stacked

loose to the turbine shroud (0.010-0.020 inch

axial clearance). The acoustic wave guide was

installed on the number three bolt and the

ODH was manually vibrated against the turbine shroud mounting flange. Figure 36 shows

the acoustic response from this test and

Indicates a signature comparable with Build 9

but with an expected lower energy level (RMS

and Count Rate).

Garrett believes that the vibratory energy

from the ODH to the turbine shroud in Build 9

contained sufficient ene, v to propagate

the existing surface defect and chip the diffuser OD at the point closest to bottom de

center.

Recommendation

To preclude the potential of this proble

the spring load across the inner/outer diffus

housing stack has been increased from 21 I

to 80 lb f.

Build 10/10A

During Build 10 assembly the compress

backshroud was replaced with update

dimensional hardware. The new hardware w

installed and a leak check performed, and e

cessive leakage was noted. Upon disassembl

it was noted that the axial stack between t

shroud/flow separator housing (FSH) seal
_..». .... ^^.. r r

J

r _ '_ X - . l.w

MANU

DUN

_ _. r.....

'LOW ENERGY BUT

IDENTICAL SIGNATURE

IL VIBRATION OF

0 TURBINE SHRO

INNER AND OUTER DIFFUSER SCREENING RIG

• WAVEGUIDE LOCATION — BOLT NO. 3 13.0'CLOCKI

RMS COUNT RATE

Figure 36. Simulated Vibration Test for Outer Diffuser Housing to Shroud.

platform resulted in a GAP, thus allowing

HP-to-LP communication. As shown in Figure

37, 0.050 Inch was removed from the FSH to

effect sealing. This unit was reassembled and

testing initiated.

On October 10, 1983, the AGT101 Ceramic

Static Structures Rig successfully qualified all

but one of a complete development engine

assembly of ceramic static structural components (Table 9) through ten (10) simulated

engine start transients to 2000 0F. A

statistical summary of the test is as follows:

• Total Light-Offs 12

• Time at 1200 OF 1 Hr 40 Min

• Time at 1500 0F 40 Min

• Time 1800 O F 40 Min

• Time at 2000 O F 1 Hr 40 Min

• Total Rig Time 5 Hrs 50 Min

At 19 minutes, 20 seconds into the fi

transient cycle (200O 0F) a 91 db event 

recorded on the FSH acoustic emiss

monitor. The count rate for the event w

approximately 450 counts indicate

probability of fracture. However, no chan

were noted In rig HP or LP inlet pressures, 

there was no fluctuation in regenerator dr

torque following the event, therefore, the t

was continued.

Air-cooled Phase IV regenerator seal te

ing was continued In Build 10 with Increa

air passage relief to accommodate hig

cooling airflow. The modified cooling p

sages had no positive effect on either 

metallic diaphragm o:, substrate temperat

over the previous configuration of Build 9

new cooled seal Configuration V is being p

sued by Ford (Phase V). The test was co

cluded following the successful completion 

10 simulated development engine start tr

sients to 20000F.

36
e

LOCATION NO. 1

RING SUPPORT HSG./FLOW

SEPARATOR HSG.INTERFACE

LOCATION NO, 2

FSH TO RING SEAL PLATFORM

0.050 STOCK REMOVED TO PROVIDE

SEAL AT LOCATION NO. 2

AXIAL SEAL POSITION —J

WITH FSH MOD

AXIAL SEAL POSITION

PRIOR TO FSH MOD

Figure 37. Stock Removed From Flow Separator Housing Platform to Provide Axial Seal.

At disassembly it was noted that the inner

diffuser housing had fractured during test and

the flow separator housing had an axial crack

along the LP £lowpath wall at the 10-11

o'clock position. The FSH fracture occurred

at the time indicated by the acoustic monitor.

FRACTURE ANALYSIS

inner Diffuser Housing

Fracture of the inner Diffuser Housing

(IDH) originated at the number 1 and number 2

bolt locations as illustrated in Figure 38.

Apparently, from investigation of the insulation, the IDH was forced against the indicated

bolt locations by a reactive load on the pilot

diameter of the insulation preform as the IDH

thermally expanded. Inadequate diametral

clearance between the IDH and the insulat

preform (in its coated and hardened conditi

has been determined the primary cause of 

fracture. With the IDH forced against 

numbers 1 and 2 bolt locations, the acou

emission probe (located on bolt number 3) 

no direct sound path to the IDH and no fr

ture signature was recorded.

Flow Separator Housing

Figure 37 illustrates the undercut requi

in the FSH mounting platform to provide ax

scaling with the turbine shroud. Dur

operation, a radial interference between 

ring support housing and the FSH mount

platform developed, as the unit was heated 

2400 0F, resulting in fracture in the under
TABLE 9. DEVELOPMENT ENGINE STATIC STRUCTURAL HARDWARE

Three Materials, Six Fabrioatlon Processes, Six Suppliers

In B/N(l0)

Component Name SIN Material Source Quantity Design Configuration

Regenerator Shield 108 SASC CRO 1 A-t

Regenerator Shield Piston Ming 003, 004 IISSC Pure Carbon 2 A-1

Flow Superstar, Housing 12 LAS Corning 1 A-2 (3-T4,1 Probes)

Regenerator Core MAS NOK I Coated Thick Wall

Transition Duct 102 SSN NOR 1 A-3 (3-T4,1 Probes)

Transition Duet Tq, 1 Bushing 004, 005, 006 SASC CDO 3 A-1

T4, 1 Inner Seal (Pomale) 004, 005, DD6 LAS Corning 3 A-I

T4, 1 Inner Seal (Male) 004, 005, 000 LAS Corning 3 A-3

T4, 1 Inner Seal Spacer 004, 005, 006 LAS Corning 3 A-1

T4,1 Inner Seal Land Spacer 004, 005, 006 LAS Corning 3 A-1

T4,1 Outer Scul (Pemulc) 004, 005, 007 LAS Corning 4 A-1

T4, 1 Outer Seal (Male) 004, 005, 007 LAS Corning 4 A-1

Combustor Baffle Ill SASC CBO I A-2 (0.200 Wall-Uniform

Turbine Baekshroud 105A SASC CBO 1 A-1

Turbine Stators (Beg.) Set 43 RBSN ACC 19 A-1

Turbine Shroud 354 RBSN ACC 1 0-3

Turbine Shroud I.D. Seal 002 RUSN ACC I A-1

Turbine Shroud Wave Spring 002 RUSN ACC 1 A-1

Turbine Shroud O.D. Seal LASS 001 RBSN ACC 1 A-1

Outer Diffuser Housing 297 RBSN ACC 1 A-3 (Dump Section)

Inner Diffuser dousing 309 RBSN ACC I D-2

Inner Diffuser Land Spacer 004, 005,006 LAS Corning 3 A-1

Bolt Assembly 007, 008, 000 HPSN Norton 3 A-1

Rocker 007, 008, 009 IIPSN Norton 3 A-1

Eccentric 007, 908, 009 HPSN Norton 3 A-1

Contract Washer (Upper) 007, 008, 009 HPSN Norton 3 A-2 (0.150 Thickness)

Contract Washer (Lower) 007, 008, 009 HPSN Norton 3 A-2 (0.150 Thickness)

Crowned Washer 007, 008, 009 HPSN Norton 3 A-I

fillet region. No secondary damage to either the

FSH or the regenerator core was observed.

4.5.4 Ceramic Turbine Rotors

4.5.4.1 Ceramic Materf>il Develooment

ACC continues to fabricate rotors of

8-percent Y203, 4-percent Al203 Compositions. Rotors are cast, dried, and presintered

by ACC; Ford continues to sinter rotors to

final density. Sintering experiments have continued at ACC and ASEA, and ACC continued to

improve rotor surface quality and yield. Efforts also continued on controlled temperature/humidity drying of the rotors to eliminate blade angle cracks.

During this period Ford sintered four rotors

to densities in excess of 98.8 percent theoretical. Three of these rotors have passed

non-destructive evaluation (NDE) inspection.

Two rotors (S/Ns 426 and 472)are prese

being machined for spin testing. The th

rotor (SIN 316) exhibited surface cracks 

was cut into test bars for evaluation. T

fourth rotor (SIN 353) is being NDE inspec

ACC sintered three rotors. Two rot

sintered at 3272 0F/100 psi N2 achieved de

ties of 96.6 percent theoretical. NDE insp

tion indicated internal defects in those ro

verified by destructive (cut-up) evaluat

One of these rotors (SIN 431) Is being use

verify and possibly calibrate the ultraso

NDE technique.

One rotor sintered at 3362 0F/15 ksi 

achieved a density of 96.5 theoretical 

passed NDE inspection. This rotor (SIN 542

being machined for spin testing.

During this period three rotors and sev

test specimens were furnished to ASE

384
Figure 38. Inner Diffuser Housing Fracture

(Structures Rig Build 10).

Sweden for glass encapsulated HIP experiments. Based on the test specimen experiments three rotors were HIP processed at

3002 oF/30 ksi achieving densities of 95-99

percent theoretical. These rotors were not

considered good quality and did not incorporate the latest ACC casting technology but

served the purpose of evaluating ASEA's densification technique. One rotor (SIN 565), which

passed visual (10-40x) inspection, was

NDE inspected and passed. This rotor is

being machined for spin testing. Table 10

presents the status of ACC rotors received by

Garrett.

The flexure strength of test bars cut from

two fully processed rotors were determined.

"The results are presented in Table 11.

4.6 Rotor Dynamic/Foil Bearing

Development

Effort continued on rotor dynamics development in support of resolving the subsynchronous motion noted during engine tes

ing. Activities have included screening fo

bearings for engine test, evaluating shaft dam

pers and Initiating a thorough thermal mappin

of the test rig environment and engine env

ronment. In addition, alternate bearing con

figurations are being investigated on an activ

basis.

4.6.1 Rotor Dynamic Rig Testing

A brush seal was designed and fabricate

for use as a shaft damper in the vicinity of th

foil bearing. Initial testing showed favorab

results in limiting subsynchronous and sy

chronous motion of the rotating assembl

Two variations (0.010 and 0.020 inch diametr

Interference) design were evaluated along wi

two shaft coating systems. Figure 39 show

the brush seal Installation.

Initial testing in the rotor dynamics r

showed improvement in suppression of th

synchronous and subsynchronous motion. How

ever, frictional heat generation and debris w

noted. A design modification was inco

porated to add additional cooling benefits 

the journal region and actively remove th

debris. However, as previously stated in Se

tion 3.2, the brush seal does not appear viab

as a long term solution. Table 12 shows pow

consumption test results for the eonfigutatio

evaluated.

4.6.2 Analysis

The foil bearing/journal environment ha

been analytically modeled using assume

boundary conditions. Results of this analys

indicated a well exhausted system thermall

however numerous bearing configurations ru

stably in the test rig while performing poor

in the engine. A major difference between th

rig and engine is the thermal environmen

therefore, installation of thermocouples (TC

directly on the foil leaves was undertake

Figures 40 through 43 depict the location an

number of TCs requested. This effort wa

underway at the close of the reporting perio

and results will be forthcoming.
TABLE 10. CERAMIC ROTORS RECEIVED FROM ACC

JULY 1 - DECEMBER 31, 1983

f

i

Rotor Process Status Comment

SIN 316 Sintered/passed NDE Cut up for test bars

SIN 426 Sintered/passed NDE Being machined for spin 

SIN 378 Sintered/failed NDE Cut up for test bar

SIN 431 Sintered/falled NDE Cut up for NDE verifica

SIN 472 Sintered/passed NDE Being machiend for spin 

SIN 565 Sintered/passed NDE Being machined for spin 

SIN 542 Sintered/passed NDE Being machined for spin 

SIN 552 Sintered Being NDE inspected

SIN 562 Presintered At Ford for sintering

SIN 563 Presintered At Ford for sintering

SIN 564 Presintered At Ford for sintering

TABLE 11. FLEXURE STRENGTH OF TEST BARS CUT FROM FULLY

PROCESSED ACC ROTORS AT ROOM TEMPERATURE AND 2200OF

Rotor

Density

Sintered by % Theoretical

Flexural Strengthl, 2

Room Temperatur e 2200OF

0 m N 0 m 

SIN 316

SIN 3783

Ford

ACC

98.8

96.7

113

95

16.6

7.5

20

20

54

51

9.5

6.6

1 1/4 point bend, 1.50-inch outer span, 0.125 x 0.250 x 2 inch-specimen

2 0 = Characteristic strength, m = Weibul slope, N = sample size

3 Rotor SIN 378 contained pores detected by NDE which were the fracture origins

40

I
Figure 39. Brush Seal Installation.

4.6.3 Alternate Bearing Svstems

I CENTERED TC ON INNER

FOIL Al EACH LOCATION

V SPAC

LOCATI

S FOIL

Due to the technical problems encountered

in resolving rotor stabiiity F two alternate systems are being pursued; Hydrodynamic Oil

Film Thrust Bearingl and Pivoted Pad Air

Bearing. The alternates address similiar but

different areas of the instability question.

A fluid film oil thrust bearing can be added

to the compressor end or the shafting inboard

of the existing ball bearing. An analytical

study was conducted to ascertain the possibilities of achieving significant radial and torsional dampening using the hydrodynamic

bearing. Results of this study were positive

and detail design and fabrication was initiated.

Figure 40. AGT Foil TC Locations.

The concept involves the utilization of 

circular thrust runner on the engine sha

Inboard of the existing ball bearing. Th

runner is straddled by two oil lubricated thru

washers that are supported by carriers fixed 

the housing. The ball bearing outer race 

retained in a hydraulic mount and is unr

strained axially except for a 10- to 50-poun

axial pre-load to prevent skidding.

Figure 44 (top half) illustrates a cro

section through the thrust and radial bearin

TABLE 12. SUMMARY OF BRUSH SEAL STEADY-STEADY POWER

CONSUMPTION AT MAXIMUM SPEED (100,000 RPM)

Shaft

Brush Seal Power Consumption, Watts

25% 50%

Coating 0.010 inch 0.020 Inch Slot Slo

Interference Interference Cutaway Cutaw

SCA:

Cooled 315 423 103 163

Uncooled 314 456 150 166

METCO 105:

Cooled 161 343 NOT 184

Uncooled 268 311 RUN 225
IuRSIRL ENO

^ r

COMPRESSOR \0]95

INO

0755

INNER EOII (

/

uee

/

lxt Exo

(C lOCg10M3

/ DI

MENSIO NS f INCHES

COMPRESSOR EN

[ 

0075

0070

Figure 41. AGT Inner Poll TC Locations.

Figure 42. AGT Outer Foil TIC Locations.

of the AGT101 engine in the baseline configuration. Note that the engine net thrust is

transmitted to the housing through the 

bearing.

Figure 44 (bottom half) illustrates a 

section through the same part of the en

when modified to accommodate the hydr

namic thrust bearing in conjunction wit

ball radial bearing.

Proper alignment of the thrust washer 

the thrust rotor at initial assembly is cr

to proper bearing operation. To assure p

alignment, the interface seat surfaces o

washer and the thrust plate assembly are 

spherical with the center of the spherical r

at the intersection of the engine shaft ce

line and a radial plate through the axial c

of the foil bearing. This configuration 

permit the thrust washer to align exactly 

with the mating thrust surface of the th

rotor. This arrangement also will sustain 

alignment through small displacements o

housing or the shaft during thermal excur

In engine operation.

The second alternate is a pivoted pa

bearing. The design heavily draws from 

successful GaP nett Brayton Rotating 

(NASA CR-1870). Benefits of the pivoted 

design include additional stiffness to th

tating system as well as damping. A sum

of salient bearing features is presented bel

Journal diameter - 1 .66 inches

Number of pads - 3

Pad effective arc length - 100 degrees

Pad width - 0.703 inch

xa7s

Figure 45 shows this bearing installed in 

engine and a sectional view is depicte

Figure 46.

42
IMI

BAI

f

TC

LEADS

0.003 WIRE

Figure 43. Foil Instrumentation.

43 
REVERSE

THRUST FLUID

FILM BEARING

THRUST ROTOR

FORWARD

THRUST FLUID

FILM BEARING

JI BEARING

CARRIER

SPHERICAL THR

PLATE ASSEMB

,kl

BALL BEAR

Figure 44. Hydrodynamic Fluid Film Thrust Bearing Installation.

44
Figure 45. Pivoted Pad Air Bearing Installed in Engine.

45
y

EEEXIBEE BEAM

f

I

I

I

UBNAL

Figure 46. Pivoted Pad Bearing - Additional Features.

46
APPENDIX A

FORD MOTOR COMPANY

ADVANCED GAS TURBINE (AGT) POWERTRAIN

SYSTEM DEVELOPMENT PROGRAM

EIGHTH AGT101 SEMI-ANNUAL

TECHNICAL PROGRESS REPORT

1. TASK 2.3 - CERAMIC ROTOR

1.1 Material Development and

Characterization

Testing of RM-3, reported in the seventh

semi-annual report, showed that this material

exhibits good oxidation behavior in the 18320F

region as well as good stress rupture behavior

up to 50 ksi at 1832 and 2192 0F. Testing

conducted this period identified a stress rupture problem for stress levels beyund 50 ksi at

both 1832 and 2192 0F. The results show that

the samples will either fall in less than 8 hours

or survive without failure for over 100 hours.

Preliminary analysis indicates that premature

failure may be related to a non-uniform flash

oxidation on the test samples. Work is continuing to improve the uniformity of the oxidation treatment.

Despite these inconsistent results at high

stress levels, the RM-3 SRBSN was shown to

exceed the stress rupture requirement of 30

ksi at 2050 0F. However, in an effort to

provide longer term material capability, development of material improvements has been

Initiated. Several modified compositions will

be Investigated and evaluated for oxidation

and stress rupture behavior. The effort will

concentrate on modifications that produce an

Inherent oxidation protection mechanism

rather than relying on flash oxidation.

Work to understand the fracture mechanisms in RM-2 material also is progressing.

Results to date Indicate that non-uniformities

in microstructure are the principal cause of

room temperature failure. The results of this

study will be incorporated in the work on

Improved material development.

1.2 Bladed Rotor Fabrication

As noted in the seventh semi-annual 

port, basic investigations were completed 

characterizing slip properties and slip behav

and models were formulated to predict s

performance. Slips with a polymer addit

have Improved the quality of cast rotors.

The slip condition is controlled by test 

density. A study to correlated nitrided den

ties of test bars and rotors, cast from t

same slip, was completed and results a

shown In Figure 47. As shown in the figu

test bars achieve a higher density than rot

when made from the same slip. This relati

ship determined the characteristics of the s

required to obtain rotors of the desired de

ity. Also notified was that the ratio of t

volume of the plaster mold to the mold s

face area influences the green density of t

bars. Data given in Figure 48 show how t

green density Is influenced by both the v

cosity of the slip and the volume-to-area ra

of plaster In the mold. These correlations 

properties of test bars and nitrided rotor$ 

necessary because the fragile condition of 

as-cast rotors precludes density measu

ments.

Sixteen rotors were cast during this per

with slips containing improved properti

Twenty rotors were nitrided with some bla

and hub cracking in each. Four serial nu

bers, V-5 9 6, 8, 9, were sintered with the b

rotor (V-9) having a density of 3.21 g/cm

These rotors all have too low a density 

testing.

As indicated in the seventh semi-ann

report, the now technique for removal of w

e
2.40 230

TEST IAR 1111111010 OTIOSITY. 919*3

n

in

Work continued during this reporting 

on the slip casting of rotors Using a mo

SRBSN material, designated RM-20

casting techniques investigated used th

mold process to produce bladed rotors fo

evaluation. The effect of ponder sizing

culating agents, and mold modificatio

being evaluated. Two rotors have bee

cessfully cast and sintered to 3.24 g

density and appear to be of high quality 

SC-1, SC-8). Rotor SIN SC-1 produc

this process was spin tested and fai

77,700 rpm. The origin of failure was a 

spherical porosity In the hub. Rotor SIN 

will be proof tested in the spin pit in th

reporting period. Six additional rotor

been slip cast and await sintering.

i

eI

s;

a

Design of the IB' configuration rotor 

tion molding tooling was completed this 

Figure 47. Rotor Vs Test Bar Density. period. The belief is that the new desig

improve changes for successful fabric

This tooling is on order and will be delive

110-1 April, 1984.

x

3

S OLVO[/AAFA

AO —a

SO--- 0

c

o `Q

SUP VISCOSITY, CPS

Figure 48. Green liensity Vs Slip Viscosity

from the fragile slip cast rotor continues to

provide cast rotors with improved quality.

The technique has been refined to the point

where there are no visible flaws evident in the

green casting, and when present, the flaws are

visible only after nitriding.

Three slip cast and nitrided SRBSN r

S/Ns 140, 146, and 149, were sent to AS

be hot isostatic pressed (HIP) in an attem

Increase density to theoretical and to 

apparent cracks in hub and blades. The 

have been returned, and SIN 140 has been 

In the cold spin pit. Failure occurr

72,000 rpm. SIN 146 will be tested in th

pit and the third rotor sectioned for ob

tion of success in crack healing.

2. TASK 2.7 -STATOR

2.1 Molded Stator Processing

Longer range plans were made to in

gate SRBSN integral stators, as noted 

seventh semi-annual report, to utiliz

proved properties of SRBSN for incr

stator reliability. Of the twenty-two s

molded with a SRBSN mix, one complet

burn-out, nitriding and sintering cycles. 

ever, the stator was badly distorted 

sintering. Sectioning of the stator rev

that the layering of the molding ma

occurred during injection molding. Dist

48
R

during sintering was caused by separation of

the material layers, which produced large

voids. Additional stators will be processed to

determine the extent of this condition.

Discussions with Garrett indicate that a

stator assembled from two half sections of the

integral stator would be useful. Several of the

2.7 g/c m 3 stators previously molded are

crack-free in a one-half section of the stator,

and these are being processed through the

burn-out and nitriding cycles. Two stators

shipped to Garrett for evaluation, S/Ns

1209206 and 1208205, await testing In the

stator thermal screening rig. These stators

contain small, tight cracks in several vane

fillet radii in both leading and trailing edges

on the shroud segmented side.

2.2 Fillet Crack Investigation

As discussed in the seventh semi-annual

report, a systematic study was conducted to

establish a relationship between molding variables and the extent of fillet cracks. During

this reporting period, a series of stators were

molded to Investigate the four variables previously identified as significant to creation of

leading and trailing edge cracks and fillet

cracks found in previous stators.

Several conclusions were obtained from

these stndies. The cracks were molding related and could be seen in green stators immediately after molding. For the same injection

molding cycle settings and sequence items,

similar crack patterns were produced. The

leading edge cracks were closely relat

the gate region and also related to ga

location, Both the leading and trailing 

cracks were reduced by changing to a ta

sprue, longer time to open the die, an

duced injection pressure.

These studies were made using a 0.0

Inch gate. Although the results sh

promise hi eliminating the fillet - -acks, s

cracks and shroud tear-out in the gate 

occurred. These problems were attribut

sticking of the molded part to the tool c

from localized overheating. increasin

gate size to 0.065 x 3 inches eliminate

overheating problem. Molding conditions 

identified that yield 50 percent or 

stators, which are free of trailing edg

leading edge cracks. Other molding condi

were identified that yield 80 percent o

stators with crack-free tailing edges. Mo

development is continuing toward prod

stators without trailing edge cracks.

During this report period, an autom

vequencer was installed on the Temperaf

tical molding machine and programmed f

AGT stator. The sequencer has demonst

excellent repeatability of the moiding 

time events.

3. TASK 2.7 — FLOW SEPARATOR HOUS

While no fabrication or development 

was scheduled for this reporting peri

purchase order for five components was p

with Corning.

O yyr `Rw/^i:rJ t^ /
APPENDIX B

AIRESEARCH CASTING COMPANY (ACC)

ADVANCED GAS TURBINE (AGT)

POWERTRAIN SYSTEM 101 DEVELOPMENT PROGRAM

EIGHTH AGT101 SEMI-ANNUAL

TECHNICAL PROGRESS REPORT

1. SUMMARY

Spin testing of rotor SIN 344, fabricated

and densified at ACC, was successfully

accomplished to 115,000 rpm, qualifying this

rotor for hot turbine rig testing. Rotor fabrication efforts have continued with improved

appearance and yield.

Effort is progressing on Code 2 rotor fabrication (6-percent Y203 and 2-percent

AL203).

Fabrication of structural components continued with activity on all components. ACC

has accepted green machining of the inner and

outer diffuser housings. This effort was initiated during this reporting period. No ACC

machined components were delivered. Table

13 is a summary of delivered components

during this period.

2. ROTOR-MATERIALS AND FABRICATION

DEVELOPMENT

Rotor SIN 344 successfully passed the

115,000 rpm cold spin test. This rotor was

fabricated and densified by ACC. Densification to 98.5 percent theoretical (3.26 g/cm3)

was accomplished in the ACC sintering furnace. The rotor then was shipped to Garrett

for NDE and machining. Following final grind,

this rotor was balanced and successfully cold

spun to 115,.00 rpm without incident.

A more controlled systematic processing

program is now being conducted to improve

effort. As noted in reference 7, elimination of

the quality and yield of the rotor fabrication

to the calcining process, continued Inve

tion of optimum deflocculants, and wax 

removal techniques, have resulted in Imp

ment In visual quality of the castings. Fu

evidence is noted In the number of r

delivered to Garrett for evaluation and 

processing. These and other processin

lated steps are being reviewed.

The partial densif feat ion/presinter 

erence 7) does not affect final densific

and will be used for shipping rotors from 

point forward. Also, presintering will b

ized on inhouse processed rotors to Imp

handling and for inprocess visual inspectio

3. CERAMIC STRUCURES

ACC, in cooperation with the mach

personnel and engineering staff at GTEC

been expanding its green machining cap

ities. During this reporting period ACC 

sonnel have visited Garrett to learn the 

niques used to machine AGT static R

components in the green condition. S

quently, green machining responsibilities 

been systematically transferred from G

to ACC.

Green machining operations at ACC 

initiated on the inner and outer diffuser 

ponents due to simplicity and the relat

stable development status, i.e., no s

changes anticipated. Machining fix

required for this activity were transf

from Garrett to ACC. The success o

initial machining transfer was followed 

transfer of green machining responsibi

for the turbine shroud and, finally, all 

ACC cast RBSN parts.

P .'::C 'rnlNG 1'AGf BLAN17; NOT FILMED

81GLiLMENTIONALL4' BLANK
52

W^ e

TABLE 13. SUMMARY OF HARDWARE ACC DELIVERED

June 1, 1983 - December 31, 1983

Component

Total Parts

Shipped Si Ns

Bladed Rotor 12 04123020316,3441378,426,431

472, 542, 552, 56% 563,564

Inner Diffuser 10 294, 298, 299, 309, 311, 317,

318, 337, 348, 366

Outer Diffuser 10 289, 296, 297, 300, 339, 340,342p

356, 364, 365

Turbine Shroud 27 307, 308, 346, 353, 354, 368, 374, 377

379, 429, 430, 432, 463, 464, 465,

466, 467, 468, 471 9 543, 544, 545,

546, 547, 548, 549, 550

Transition Duct 1 210

Turbine Shroud Seal Ring 9 320, 321, 322, 323, 324, 358, 359,

360, 361

Turbine Shroud Seal Spring 12 246, 250, 259, 260, 261, 262, 263,

264, 265, 266, 267, 268

Stator Segments 43 Set 004 - S/Ns 222 - 236

Set 005 - S/Ns 433 - 462
APPENDIX C

THE CARBORUNDUM COMPANY

(UNIQUE WORK)

ADVANCED GAS TURBINE (AGT)

POWERTRAIN SYSTEM DEVELOPMENT PROGRAM

EIGHTH AGT101 SEMI-ANNUAL

TECHNICAL PROGRESS REPORT

1. BACKGROUND

This report summarizes the work carried

out on static structures during the time period

July 1, 1983 through December 31, 1983. Carborundum continued to work on six different

SASC components. Two advanced forming

methods, plastic extrusion and plastic forming,

were employed in addition to the already

proven techniques of injection molding, slip

casting, and isoprH,:sing/green machining.

Both ceramic forming techniques were introduced to the AGTI01 program after being

successfully developed for fabricating parts of

different shapes with similar compositions.

Plastic forming was Introduced for the

fabrication of combustor baffles which had

been made by slip casting and subsequent

green machining of the Internal profile to

obtain an essentially constant wall thickness.

The new method was chosen with the goal of

Improving net shape forming capabilities and

eliminating green machining. Plastic extrusion has been chosen as a fabrication method

for combustor liners and regenerator shields

which so far had been supplied using

isopressing/green machining and final grinding.

The change to this fabrication technique

reflects the overall goal of employing fabrication methods that have high volume, low cost

potential. Individual stator segments and turbine shrouds were made by injection molding

as in previous years. Isopressing/green

machining remained the fabrication process

for the transition duct.

2.0 SUMMARY

During this reporting period Carborundum

supplied seven as-fired combustor baffles

made by slip casting and green machining, tw

sets of as-fired stator segments, fo

machined transition ducts and one grou

regenerator shield made by Isopressing a

green machining. Combustor baffles, tran

tion ducts and regenerator shields hav

repeatedly performed well In various rig te

at Garrett. Because of these successes o

combustor baffles the same bimodal ratio w

chosen for the plastic forming composition 

far as for the casting slip. The feeling w

that the 85-90 percent of theoretical densi

contributed positively to the combustor baff

performance in the severe thermal shock co

ditions of a 2100°F rig test.

3.0 STATIC STRUCTURES

3.1 Turbine Stator

Individual SASC stator segments we

made by Injection molding. A new Improve

Injection molding compound with a differe

plastic system and a somewhat higher plast

content was used to make stator segments 

the mold designed for the previously employ

system. The new compound (B) is superior 

the old one (A) by producing parts with le

molding defects or flow lines. Parts made 

compound B also exhibit less sintering disto

tion. A set of parameters was Investigated 

alter and sufficiently influence shrinkage du

ing sintering to obtain parts to print. 

addition, a new tool that Incorporates dire

tional shrink factors as determined for com

pound B was designed and obtained at the en

of this reporting period.

The following highlights relate to activiti

carried out on parts molded in the old tool.
0 Previously molded and baked stator segments made with composition modifications B-2 and B-3, whereby B-2 has a

higher plastic content than B-3, were

sintered at temperatures lower than standard.

0 A matrix approach was used In determining

the sintering temperature that would yield

the best dimensions In connection with an

acceptable final density for each of these

mix modifications.

0 Stator segments made with B-3 compound

that were sintered at the lowest matrix

temperature gave the best overall dimensional results. Correspondingly made MOR

bars were processed using the same sintering parameters.

0 Thirty stator segments of composition B-2

and 100 of B-3 were sintered at the newly

established conditions.

0 Forty-six B-3 stator segments (2 sets)

passed all the required inspection steps but

were still slightly under size. The parts

were sent to Garrett for evaluation.

0 Standard mix was used for molding 250

stator segments. All parts were processed

using standard procedures and conditions.

Some of these parts were used to determine mold dimensions for a new injection

molding tool.

0 The remaining parts were used for fixturing experiments during sintering. Warpage

of the sidewalls, flaring at the ends and

some distortion in the trailing edge necessitated additional design work on the

sintering fixtures. A configuration was

developed that was successful in eliminating these deviations.

o Forty new sintering fixtures were obtained.

o Standard compound has been prepared for

use in the new injection molding tools that

had been received at the end of the reporting period.

3.2 Turbine Shroud

The turbine shroud, at about 15 pounds 

the largest injection molded SASC part pr

cessed by Carborundum and is made on a 100

ton injection molding machine at a custom

molder. Work on the newly designed turbi

shroud, Drawing PA3609679, was resumed d

ing the second half of this reporting period.

o The old injection moldinv tooling w

redesigned and modified ;n areas with s

ficient stock to accommodate the ne

requirements. However, additional gre

machining of the as-molded parts will 

necessary to .obtain ail aspects of the ne

design. Additional grinding stock in t

flange area was incorporated to allow f

some distortion during sintering.

o Two different mixes (B and D) were co

pounded.

• An injection molding run was scheduled f

December 1983 and yielded 19 turbi

shrouds of mix B and 20 of mix D f

further processing.

• All parts show some flow lines. Most 

the flow lines, however, are in areas whe

stock will be removed during gree

machining (Figure 49)

• Four shrouds were gr i machined in th

as-molded state (Figure 50) and will 

submitted for initial NDE inspection.

3.3 Combustor Baffle

The combustor baffle has been fabricat

by slip casting using a bimodal water base

SIC composition. The drain casting metho

used yields a reproducible outside configur

tion but additional green machining of t

inside contour is necessary to obtain t

desired profile with constant wall thickness.

An advanced plastic forming method h

been chosen to replace slip casting as a for

ing process. The new method is expected 

produce combustor baffles near net shap

54

o
ORlGmft 

P;,' i ^f

OF POOR

Figure 49. As- Molded Turbine Shroud.

Figure 50. Green Machined Turbine Shroud.

eliminating all green machining work. An

attempt is made to cloEely duplicate the

bimodal ratio of the SiC powder of the casting

slurry to obtain a comparable final density.

Paragraphs 3.3.1 and 3.3.2 summarize 

activities on combustor baffles carried ou

both forming methods:

3.3.1 Combustor Baffle (Cast

o Fifty combustor baffles were cast be

work in this area was halted. The p

subsequently were processed throug

drying and high temperature bake.

c, Thirty parts were green machined on 

inside contour and cleaned prior to sin

ing.

n Seven completely processed combu

baffles passed as-fired NDF, inspection 

were shipped to Garrett with correspon

MOR bars.

o One combustor baffle remains as work

process in NDE.

3.3.2 Combustor Baffle (Plastic Forming)

o Initial trials were conducted on 

bimodal plastic compounds (P-1 and 

which varied in the plastic content 

compound P ­ 2 having less plastics t

P-1.

o Both compounds showed good mold

characteristics but compound P-`l was 

susceptible to bake-out problems and 

therefore chosen for further forming tr

o Flat disks of 1/2 to 1 inch thickness w

formed using different molding press

and temperatures. These disks were u

for initial shrinkage, density, and stren

deter inations.

o The steel tool for the eombut,,tor baffle 

received and first trials showed good 

face quality on the as-molded parts, 

cracking on the 1D and partially unfi

locating tabs necessitated revisions of 

mold and the insert.

o The problem of proper flow and fil

characteristics to obtain a homogeneo

^u^-93761
dense body with good surface quality was

addressed by evaluating different methods

of charging the mold.

o New molding trials are scheduled for early

January 1984.

3.4 Transition Duet

This part has been made by isopressing a

tube billet and green machining the inside and

outside contour using a CNC lathe. Each part

is sintered on a contoured mandrel and only

minor grinding work is required on the ends

and the inside platform (transition duct/

combustor baffle Interface).

o Six tube billets were isopressed.

o Two of these parts were made using submicron SIC powder having a modified

particle size distribution.

o Parts from the previous as well as current

reporting period have been Identically

processed according to standard procedures.

o Four machined transition ducts corresponding basically to drawing 3846232 were

completed and shipped with corresponding

MOR bars to Garrett. Slight design modifications are being incorporated per

request as soon as feasible. All of the

shipped parts had additional stock on the

platform and the last transition duct also

Incorporated additional stock in length

(transition duct/turbine shroud interface).

o Three transition ducts were green

machined, passed green Inspection, and will

be sintered in early January 1984.

3.5 Combustor Liner

Plastic extrusion has been chosen to

replace isopressing/green machining as the

forming process for combustor liners. This

part is ideally suited for this new processing

technique, which has a high volume potential.

Current activities are focused on scale up with

respect to extrusion and processing of 

diameter tubing.

o Standard extrusion mix was compoun

no mix variations were undertaken.

• All parts were extruded at a custom m

Ing facility. Extrusion experiments 

respect to temperature distribution

extrusion spud were conducted. Mod

tions of take-up equipment were nece

for minimizing deformation and adequ

controlling cool-down.

• Initially extruded parts were oversize

the OD, showed surface Imperfection

Internal defects.

o Additional stock was subsequently in

porated by enlarging the extrusion 

The distribution of the extrusion tem

tures was changed, eliminating most o

visually detectable surface flaws.

• A new extrusion run was conducted 

during this reporting period yielding 

stock for about 26 Individual liners.

• Various bake-out and sintering techni

were investigated and a set of new 

cedures was established.

• Two parts progressed through bake-ou

sintering and are currently in grinding.

3.6 Regenerator Shield

Previously supplied parts were mad

isopressing/green machining and final grin

Again plastic extrusion was chosen a

advanced forming process for this compo

minimizing powder requirements and elim

ing green machining costs.

o The first extrusion trial was unsucce

because of insufficient filling pres

supplied by the extruder originally cho

o Scale-up problems were encountered 

dies for a larger extruder and spe

take-up equipment for this extruder h

56
M

be designed. The green extruded tube has

roughly a diameter of 7 and 3/4 Inches, a

considerable step up from the combustor

liner which has about a 5-Inch diameter.

o Because of the delay in obtaining adequate

forming equipment and the need for

delivering ground parts to Garrett two

isopressed/green machined parts were

initiated in September 1983.

• Both isopressed/green machined parts were

processed through sintering and as-fired

NDE. One of these parts remains In grinding; the other was ground, passed final QC

and was shipped to Garrett with corresponding MOR bars.

• Two additional Isopressed billets were prepared In December 1983, green machined

and sintered.

o The parts passed as-fired QC and w

submitted for final grinding.

o The second extrusion run, using a la

extruder produced tube stock, which yi

about 26 Individual regenerator shields.

o Four extruded regenerator shields were 

to size, inspected, and submitted for bin

removal.

o One of these parts completed bake-o

was sintered and submitted for as-f

QC.

o All work-in-process, isopressed/gre

machined and extruded, will be proces

parallel to meet delivery requirements.
APPENDIX D

LiST OF SYMBOLS, ABBREVIATIONS AND ACRONYMS

Acronyms i Definition

ACC AiResearch Casting Company

ACT advanced gas turbine

AGT101 the ACT model being developed by Garrett/Ford

Al 2O3 aluminum oxide

AS aluminum silicate

BN Borazon

I oC degrees Celsius

CBO The Carborundum Company

CL clearance probes

CFDC Combined Federal Driving Cycle

CNC computer numerical control

CO carbon monoxide

j CO2 carbon dioxide

DAW dual alloy wheel

DFC diffusion flame combustor

DOE U.S. Department of Energy

DS directionally solidifed

ECU electronic control unit

EDX energy dispersive X-ray

EPA Environmental Protection Agency

OF degrees Fahrenheit

Ford 707 an industrial gas turbine engine by Ford

FY fiscal year

GE General Electric Company

HC hydrocarbon

HCI hydrogen chloride

HexoloyTM KXO1 Carborundum material, SIC

ff HexoloyTM KX02 Carborundum material, SIC

HexoloyTM SA Carborundum material, SIC

Hf halfnium

HiP hot isostatic pressing

HP high pressure regenerator inlet (cold side)

HTP high temperature protection, Lockheed

1 Hz Hertz (frequency)

ID inner diameter

IGV inlet guide vane (compressor)

# IR&D Internal research and development

1-112 regenerator seal coating material

G

JP-4 jet propulsion fuel Number 4

+ ksi thousand pounds per square inch

d l lb/min pounds per minute

lb-ft pound feet (of torque)

z' LBO lean blowout

58
LIST OF SYMBOLS, ABBREVIATIONS AND ACRONYMS (Contd)

Acronyms Definition

LCF low cycle fatigue

LDV laser Doppler velocimeter

LP low pressure regenerator inlet (hot side)

"m" Weibull modulus

MAS magnesium aluminum silicate

MEK methyl ethyl ketone

MENTOR II Ford regenerator computer program

METCO 443 flame spray coating

METCO 447 flame spray coating

MgO magnesium oxide

Mod I first development engine

Mod II second generation ceramic engine

MOR modulus of rupture

N rotational speed

Nos population, number of samples

NASA National Aeronautics and Space Administration

NGK NGK-Locke, Inc.

NiCr nickel chrome alloy

NOx oxides of nitrogen

OD, outer diameter

PM powder metal

PN part number

LB/MIN pounds per minute

LB/HR pounds per hour

PRC compressor pressure ratio

PS static pressure

PRT turbine pressure ratio

psis pounds pressure per square inch, absolute

psid pounds pressure per square inch, differential

psig pounds pressure per square inch, gauge

PT total pressure

PWM pulse width modulated

RBN 104 ACC RBSN material

RSN 124 ACC RBSN material

RBSIC reaction bonded silicon carbide

RBSN reaction bonded silicon nitride

RCG reaction cured glass, Lockheed

RM-1 Ford rotor material, first generation

RM-2 Ford rotor material, second generation

RM-3 Ford rotor material, third generation

RMS root mean square

RPD referer.--e powertrain design

rpm revolutions per minute

RSSiC reaction sintered silicon carbide

SASC Carborundum material, HexoloyTM, a-SIC

SEM scanning electron microscopy

59
LIST OF SYMBOLS, ABBREVIATIONS AND ACRONYMS (Contd)

Acronyms Definition

Sic silicon carbide

Si3N4 silicon nitride

SMD Sauter mean diameter

SIN serial number

SNN 522 ACCsintered silicon nitride

SN-50 NCR silicon nitride material

SR stress rupture

SRBSN sintered RBSN

TC thermocouple.

TD theoretical density

TiR total indicator reading

TIT turbine inlet Temperature

TRW Thompson Ramo Woldridge

TT total temperature

T-T total-to-total

VIC V variable Inlet guide vane

Wt speed

W tungsten

W-K Wayac -Kerr

yo-yo Astroloy heat treat cycle

Y2O3 yttrium oxide

S beta

AT/T delta temperature/temperature standard

P micro strain

AP/P delta pressure/pressure standard

A characteristic strength

60
REFERENCES

1) Garrett Turbine Engine Company, "Advanced Gas Turbine (ACT) Powertrain System Development for Automotive Applications", Semiannual Progress Report Number 1 (October 1979 through June 1980),

NASA Report CR- 165175, November

1980, Contract DEN3-167.

2) Garrett Turbine Engine Company, "Advanced Gas Turbine (ACT) Powertrain Sys-,

tem Development for Automotive Applications", Semiannual Progress Report Number 2. (July 1980 through December 1980),

NASA Report CR-165329, June 1981,

Contract DEN3-167.

3) Garrett Turbine Engine Company, "Advanced Gas Turbine (ACT) Powertrain System Development for Automotive Applications", Semiannual Progress Report Number 3 (January 1981 through June 1981),

NASA Report CR- 167901, December

1981, Contract DEN3-167.

4) Garrett Turbine Engine Company, "Advanced Gas Turbine (ACT) Powertrain System Development for Automotive Applies

bons", Semiannual Progress Report Number 4. (July 1981 through Decemb

(1981), NASA Report CR-167983 1 Ju

1982, Contract DEN3-167.

5) Garrett Turbine Engine Company, "A

vanced Gas Turbine (ACT) Powertrain S

tem Development for Automotive Appli

tions," Semiannual Progress Report Nu

ber 5. (January 1982 through June 198

NASA Report CR-168104, Decemb

1982, Contract DEN3-167.

6) Garrett Turbine Engine Company, "A

vanced Gas Turbine (ACT) Powertrain S

tem Development for Automotive Applic

tions," Semiannual Progress Report Nu

ber 6. (July 1982 through December 198

NASA Report CR-168246 June 198

Contract DEN3-167.

7) Garrett Turbine Engine Company, "A

vanced Gas Turbine (ACT) Powertrain Sy

tem Development for Automotive Applic

tions^, Semiannual Progress Report Num

ber 7. (January 1983 through June 198

NASA Report CR-174694 Decemb

1983, Contract DEN3-167.