EN

GIN

E T

RA

NS

IEN

T T

HE

RM

AL

BE

HA

VIO

R A

ND

TU

RB

INE

BLA

DE

TIP

C

LEA

RA

NC

E C

ON

TR

OL

Dr.

Bor

is G

leze

r,O

ptim

ized

Tur

bine

Sol

utio

ns, U

SA

11th

Isra

eli S

ympo

sium

on

Jet E

ngin

es a

nd G

as T

urbi

nes

,O

ctob

er 2

5, 2

012

Prio

r an

d F

utur

e P

rese

ntat

ions

on

the

Sub

ject

:1.

“Tur

bine

Bla

de T

ip D

esig

n an

d T

ip C

lear

ance

Tre

atm

ent”

, Von

Kar

man

In

stitu

te fo

r F

luid

Dyn

amic

s Le

ctur

e S

erie

s 20

04-0

1, V

KI

2004

2. “

Tur

bine

Bla

de T

ip In

tern

atio

nal S

ympo

sium

and

Tra

inin

g W

orks

hop”

Ham

burg

, Ger

man

y, S

ep. 3

0-O

ct.3

, 201

3

Pre

sent

atio

n O

bjec

tives

•A

DD

RE

SS

IMP

OR

TA

NC

E O

F T

HE

RM

AL

TR

AN

SIE

NT

S

FO

R E

NG

INE

DU

RA

BIL

ITY

AN

D P

ER

FO

RM

AN

CE

•E

MP

HA

SIZ

E C

RIT

ICA

L R

OLE

OF

BLA

DE

TIP

C

LEA

RA

NC

E (

TC

) V

AR

IAT

ION

DU

RIN

G T

RA

NS

IEN

TS

•IN

VE

ST

IGA

TE

TY

PIC

AL

RE

AS

ON

S C

AU

SIN

G T

IP

CLE

AR

AN

CE

PR

OB

LEM

S

•D

EM

ON

ST

RA

TE

EF

FE

CT

S O

F E

NG

INE

AP

PLI

CA

TIO

N

ON

TC

CO

NT

RO

L F

OR

AE

RO

AN

D IN

DU

ST

RIA

L E

NG

INE

S

•IL

LUS

TR

AT

E P

OS

SIB

LE M

EA

NS

OF

TC

IIM

PR

OV

EM

EN

T

Tw

o R

ealis

tic E

xtre

mes

Of T

urbi

ne S

truc

ture

Indu

stria

l App

licat

ion

Airc

raft

App

licat

ion

Ma

in E

ngin

e T

herm

al T

rans

ient

Issu

es

App

ly h

oi s

ide

TB

C;

use

curv

ed r

adia

lly

vane

trai

ling

edge

an

d/or

mat

chin

g sh

roud

thic

knes

s

Hig

h he

at lo

ad fr

om

com

bust

or s

ide

vers

us in

tens

ive

back

side

coo

ling;

h

igh

van

e ax

ial ∆

T

Com

bust

or li

ner

and

cool

ed n

ozzl

e va

ne

trai

ling

edge

(bu

cklin

g)

Exc

essi

ve lo

cal

tran

sien

t the

rmal

st

ress

Use

hon

eyco

mbs

, co

nsid

er b

rush

sea

ls,

cera

mic

s

Exc

essi

ve r

adia

l and

ax

ial r

otor

-to-

stat

or

tran

sien

t tra

vel

Prim

arily

rim

sea

ls a

nd

inte

rsta

ge s

eals

Lab

yrin

th

seal

d

ama

ge

Atte

mpt

ther

mal

m

atch

ing;

app

ly

pass

ive

and

activ

e m

etho

ds fo

r tip

cl

eara

nce

cont

rol

Rel

ativ

e ro

tor-

to

stat

or/c

ase

tran

sien

t di

spla

cem

ents

,ci

rcum

fere

ntia

l te

mpe

ratu

re v

aria

tion

in a

sta

tor

Prim

arily

firs

t tur

bine

st

ages

and

last

co

mpr

esso

r st

ages

Bla

de t

ip r

ubs

(per

form

ance

lo

ss a

nd p

ossi

ble

seve

re d

amag

e)

Pre

vent

hot

gas

in

gres

s in

to in

ner

cavi

ties,

incr

ease

bl

ade

shan

k le

ngth

, m

inim

ize

blad

e-to

-di

sc c

onta

ct a

rea

Hig

h he

at fl

ux a

t the

rim

cou

pled

with

low

co

nduc

tivity

tow

ard

cent

er

Rot

or d

iscs

, sta

tiona

ry

diap

hrag

ms

and

rota

ting

plat

esex

pose

d to

cyc

lic

yiel

ding

str

esse

s

Tra

nsie

nt th

erm

al

stre

ss fr

om

hig

h ra

dia

l ∆T

(LC

F)

Pos

sibl

e so

lutio

nsM

ain

caus

eA

ffect

ed

com

pone

ntP

robl

em

(Ref

. var

ious

NA

SA

stu

dies

)

Non

-equ

al r

otor

-to

stat

or a

xial

ther

mal

dis

plac

emen

t rel

ativ

ely

to th

rust

bea

ring

Diff

eren

t rad

ial

tran

sien

t the

rmal

grow

s fo

r di

scs

and

stat

or

ρ·c

·V/ (

h ·A

s)T

ime

cons

tant

durin

g a

com

pone

nt h

eatin

g or

co

olin

g co

rres

pond

s to

a

mom

ent w

hen ∆

Ti=

63.2

%of

the

tota

l ∆T

at

the

stea

dy

stat

e

63.2

%

Initi

al e

quili

briu

m

T, h

, A

Indu

stria

l Cas

ing

Aero Casing

Tem

pera

ture

Res

pons

e of

Typ

ical

Com

pres

sor

or T

urbi

ne D

isc

Dur

ing

Star

t

Dis

c R

im

Dis

c B

ore

(Hub

)

Eff

ect

of B

lade

Rea

ctio

n an

d C

lear

ance

/Bla

de

Hei

ght

Rat

io o

n St

age

Eff

icie

ncy

% C

lear

ance

/h

Relative Stage Efficiency

Effe

ct o

f Bla

de T

ip “

Unl

oadi

ng”

LOSS OF

1% C

lear

ance

Mai

n C

ontr

ibut

ors

To

TC

Pro

blem

:

* L

ack

of r

otor

-sta

tor

ther

mal

mat

chin

g*

Poo

r th

erm

al is

olat

ion

of s

hrou

d su

ppor

t str

uctu

re fr

om

the

gas

stre

am

* F

ailu

re to

pro

vide

con

cent

ricity

bet

wee

n ro

tor

and

co

rres

pond

ing

shro

ud lo

catio

n du

ring

tran

sien

ts*

Ove

rlook

ing

effe

ct o

f thr

ust b

earin

g lo

catio

n w

hen

axia

l th

erm

al g

row

th is

impo

rtan

t *

Lac

k of

des

ign

prov

isio

n fo

r m

inim

al d

amag

e fr

om ti

p ru

b*

Exc

essi

ve a

ccum

ulat

ed a

ssem

bly

tole

ranc

es

Impo

rtan

ce o

f Sup

port

Str

uctu

re a

nd B

earin

gs

Pos

ition

for

Tip

Cle

aran

ce C

ontr

ol

Sel

f sup

port

ed in

tegr

al n

ozzl

es –

blad

e tip

shr

oud

Diff

eren

t Opt

ions

for

Tur

bine

Noz

zle

Sup

port

Typ

ical

two-

vane

per

seg

men

t

nozz

les

need

sup

port

cas

ing

Inte

gral

noz

zle

cast

ing

Ver

y se

nsiti

ve to

ther

mal

dis

tort

ions

rela

ted

to c

ircum

fere

ntia

l ∆T

Stat

or S

truc

tura

l Des

ign

Req

uire

men

ts

•A

TT

EM

PT

TO

AC

HIE

VE

CL

OSE

TR

AN

SIE

NT

TH

ER

MA

L M

AT

CH

ING

BE

TW

EE

N R

OT

OR

AN

D

STA

TO

R

•ST

AT

OR

DE

SIG

N H

AS

TO

PR

OV

IDE

CIR

CU

MF

ER

EN

TIA

LL

Y U

NIF

OR

M T

EM

PE

RA

TU

RE

S A

ND

ST

AT

OR

RO

UN

DN

ESS

RE

GA

RD

LE

SS G

AS

PA

TH

TE

MP

ER

AT

UR

E V

AR

IAT

ION

S

•C

OM

PO

NE

NT

S A

SSE

MB

LY

HA

S T

O K

EE

P S

EG

ME

NT

ED

SH

RO

UD

EL

EM

EN

TS

RO

UN

DA

ND

C

EN

TE

RE

D

•ST

RIV

E T

O A

CH

IEV

E M

INIM

AL

TIP

CL

EA

RA

NC

E A

T M

AX

PO

WE

R S

TE

AD

Y S

TA

TE

•L

IGH

T T

IP R

UB

S D

UR

ING

TR

AN

SIE

NT

S SH

OU

LD

NO

T C

OM

PR

OM

ISE

RO

TO

R I

NT

EG

RIT

Y

•BL

AD

E T

IP D

ESI

GN

SH

OU

LD

PE

RM

IT T

IP W

EA

R W

ITH

OU

T M

ET

AL

TR

AN

SFE

R T

O T

HE

SH

RO

UD

•T

AP

ER

ED

BL

AD

E T

IPS

RE

QU

IRE

OP

TIM

IZE

DL

OC

AT

ION

OF

RO

TO

R T

HR

UST

BE

AR

ING

•D

ESI

GN

AN

D C

OO

LIN

G O

F S

TA

TO

R C

OM

PO

NE

NT

S SH

OU

LD

PR

EV

EN

T T

IP R

UB

SA

T H

OT

R

EST

AR

TS

•B

EA

RIN

G H

OU

SIN

G D

ESI

GN

HA

S T

O K

EE

P R

OT

OR

CE

NT

ER

ED

AT

AL

L O

PE

RA

TIN

G

CO

ND

ITIO

NS

•D

ESI

GN

SH

OU

LD

HA

VE

FL

EX

IBIL

ITY

TO

TU

NE

ST

AT

OR

CO

NF

IGU

RA

TIO

N A

ND

CO

OL

ING

•P

ASS

IVE

OR

AC

TIV

E T

IP C

LE

AR

AN

CE

CO

NT

RO

L M

EA

NS

AR

E R

EQ

UIR

ED

WH

EN

TR

AN

SIE

NT

T

HE

RM

AL

M

AT

CH

ING

BE

TW

EE

N R

OT

OR

AN

D S

TA

TO

R I

S N

OT

AC

HIE

VA

BL

E

Effe

ct o

f Tip

Cle

aran

ce o

n T

urbi

ne E

ffici

ency

Tip

Dur

abili

ty C

once

rns

TIT

,

Tra

nsie

nt th

erm

al

dis

pla

cem

ent

is p

rim

arily

a

func

tion

of p

art’s

vo

lum

e,

tem

per

atur

e an

d e

xpan

sio

n co

effic

ient

Tip

Cle

aran

ce C

ontr

ol O

ptio

ns

•P

AS

SIV

E–B

AS

ED

ON

TU

RB

INE

DE

SIG

N P

RO

VIS

ION

S

•S

EM

I-A

CT

IVE

–O

PE

N/C

LOS

ED

PO

SIT

ION

S F

OR

C

OO

LIN

G/H

EA

TIN

G M

ED

IA

•A

CT

IVE

–C

ON

TIN

UO

US

MO

DU

LAT

ION

OF

ST

AT

OR

C

OO

LIN

G/H

EA

TIN

G

Pas

sive

Tip

Cle

aran

ce C

ontr

ol M

etho

ds

(

OR

NO

N-T

RA

DIT

ION

AL

DE

SIG

N

(Fou

r La

yers

)

Adj

ustm

ents

pin

s

The

rmal

Dro

op o

f B

eari

ng H

ousi

ng (

oil s

ump)

an

d R

esul

ting

Los

s of

Rot

or C

once

ntri

city

Sta

tor

Allo

ys

Dis

c A

lloys

Ti-9

Al-4

V

Coe

ffici

ents

of T

herm

alE

xpan

sion

for

Med

ium

and

H

igh

Tem

pera

ture

Mat

eria

ls

(So

lar

Pat

ent)

Sol

utio

n

conc

ept

Pro

blem

reve

aled

Hou

sing

Exp

ansi

on

Rot

or E

xpan

sion

Eng

ine

Mou

nt

Pla

ne

Min

imiz

ing

Tra

nsi

ent T

C b

y E

mp

loyi

ng

Axi

al T

her

mal

T

rave

l

Act

ive

Tip

Cle

aran

ce C

ontr

ol M

odul

atin

g B

ypas

s A

ir F

low

Typ

ical

Des

ign

for

Sta

ge 1

HP

T C

oolin

g S

upp

ly(E

3E

ngi

ne,

ref

. N

AS

A C

R-1

680

69, D

ec1

982

)

Exa

mpl

e of

a S

ucce

ssfu

l Aer

oder

ivat

ive

Eng

ine

(GE

LM

6000

)

Ope

nC

lose

d

Tur

bine

Dis

c Se

mi-

Act

ive

The

rmal

Gro

wth

Con

trol

Tur

bine

Dis

cs T

herm

al G

row

th C

ontr

ol

(Pro

ven

Con

cept

)

X

(Sol

ar T

urbi

nes

Pat

ent)

thro

ugh

bore

scop

epo

rt

Con

clud

ing

Rem

arks

(10

blad

e ti

p cl

eara

nce

com

man

dmen

ts)

•P

ER

FO

RM

AN

CE

GA

INS

JUST

IFY

OU

TM

OST

EF

FO

RT

S IN

M

INIM

IZIN

G T

IP C

LE

AR

AN

CE

S •

RO

TO

R-T

O -

STA

TO

R T

HE

RM

AL

MA

TC

HIN

G I

S A

KE

Y F

OR

P

ASS

IVE

TC

CO

NT

RO

L•

UN

IFO

RM

NO

-RU

B T

C R

EQ

UIR

E M

INIM

AL

TE

MP

ER

AT

UR

E

GR

AD

IEN

TS

IN S

TA

TO

R C

OM

PO

NE

NT

S•

LO

W T

HE

RM

AL

EX

PA

NSI

ON

AL

LO

YS

AN

D C

ER

AM

ICS

CA

N A

SSIS

T

IN A

CH

IEV

ING

SM

AL

L T

C•

PR

OP

ER

DE

SIG

N O

F R

OT

OR

SU

PP

OR

T S

TR

UC

TU

RE

IS

RE

QU

IRE

D

FO

R O

BT

AIN

ING

UN

IFO

RM

TIP

AN

D S

EA

L C

LE

AR

AN

CE

S•

TH

RU

ST B

EA

RIN

G P

OSI

TIO

NIN

G P

LA

YS

IMP

OR

TA

NT

RO

LE

FO

R

TA

PE

RE

D B

LA

DE

TC

•A

CT

IVE

TC

CO

NT

RO

L I

S U

SUA

LL

Y R

EQ

UIR

ED

FO

R L

IGH

T

WE

IGH

T A

ER

OE

NG

INE

ST

RU

CT

UR

ES

•C

RE

AT

IVE

DE

SIG

N T

EC

HN

IQU

ES

FO

R A

CH

IEV

ING

TR

AN

SIE

NT

T

HE

RM

AL

MA

TC

HIN

G C

AN

SIG

NIF

ICA

NT

LY

IM

PR

OV

E T

C•

TH

OR

OU

GH

RE

LA

TIV

E R

OT

OR

-TO

-ST

AT

OR

TR

AN

SIE

NT

D

ISP

LA

CE

ME

NT

AN

AL

YSE

S M

UST

BE

CA

RR

IED

OU

T A

FT

ER

C

OM

PL

ET

ION

OF

PR

EL

IMIN

AR

Y D

ESI

GN

•F

INA

L D

ESI

GN

VA

LID

AT

ION

RE

QU

IRE

S A

PP

LIC

AT

ION

OF

A

CC

UR

AT

E T

C M

EA

SUR

EM

EN

T M

ET

HO

DS