The effect of tip clearance flows on performance of axial flow compressors

T

-

S^..ng% ^{A '*'d -"-} F: TT ^{*. W*?.} _{*; AdL} ^{*P ' 3} _{* -j t .} ^I-' _{3 2} ^--I- _rj;.p "~;L~&BL"p&4$J;;C~~ 'yL*f-:..'" ^", ,* ^{2 %} .. i i ,*."\" --,t,.,c..--i,xn%p,PP~~ii-ii~~p, ,-+--Y1 ,4.:?.-> ^I y* S Z V - ; . . r T > . - 4 ----

L?:.: c. :.&i&# L>:<-*-.~- ,*i.;&"*,':a t.J.5 ^{,m L,} ,&$.A> -- ^{>a* .%*- * I::, td4} 4*.jAS&.k~ *:.?j:;;2&3 3:2!5

2, 'Variatian wI"G:l Tip a e b r a t c s

P-2 i or ^?..-sod ^. e S i c i e c y s$ a ;as t a r h i * e cj~cLe, it Be a.z&o.rr.atfc $&az

& t s e ~ o 6 - ~ - , 3 a r e ~ ~ ~ ; r & a % f ~ a B % i ~ I 1 e @ i ~ i e i % c y ~ & a ~ - = i r ~ ~ ; * ~ $ @ 1 ~ ~ ~ & ~ $ ~ ~ ~ f ~ ~ 6 ~ b ; ~ ^-7 ,

the cazTgra@oor are tE?.::cses due t o l e d c a g e Bows tCre=azzgh eke tip clearaaca.

'1, 2, 33

1% ;x?,ae @ : l o Q ~ ~ k tinat t k a var%;i+tio of tip c I e b x 8 ~8 ha@ an %r*$- portaa:t effect o i ym-fp &ad c:oi%presssr pasformai~se, P:3 ~jardieadar,

f ' 7 $

~&r.:crj""3:l%*e~~~ated fin detail the tip clesrasce ^Bkivg i m e c h & ~ i a ~ q eIId variatf o i fia compree;;sor p a ~ f ~ s : : : ~ a n c a with tip clear&ce;e a e t 2 1 ~ deoizs2

-

^,-

~ O rS"i@, W ^{e k e} inEro&ared a perfzct

a~d&

EITW .model and correctiora~ $or real fluid af$ects to _eoml2ara wit?? e : q ~ ~ ~ r i : z e n t ~ ~ ⁸⁰ t h a t va?:iaa,$~ i n ~'ior~a- gzeseor pex4sri--:arLc@ could be oszirnated $ 0 ~ ~ t h a r 0;$er&3.:rg eo~-dfj;lo:~a a d other machinese

~"ile pr@oesiE invastijati9-I f e ssnesrnad with deter;i"s% ^%2lg the efdecl o$ tPp cf@arza:~cs; @a;. c o ~ ~ ~ g s e ~ 1 - z o s p e ~ f o m n ~ ~ c e , 2ot 0;11y a0 Bsel2.l c s ~ ~ d i - - eiafis, but also through a rn, gc sf 2 2 rate@ ~ ~from .tear @tall f=o -;..ell a h v e d ~ g i g z . ~ for the p u r p o ~ e of gaining i x o r e a ~ ~ d e r @ t a i i & , q of the t i p Bow

n ~ s c h = ~ P @ ~ = &:d to e5ztej-id the raSs' ~ e , of ~ 1 f 3 0 r n p a ~ r i m of t&@ @~~sri-b~lelrft@ with the ~ i 2 ~ " g e ~ t .fI?id. ~~~10d41 a id Q ~ i d C Q F ~ ~ C & $ ~ + , @ g i ~ e - 1 ^%AT FL@fere&zca 2.

-

_{IIYv -A a&@} " v * ^ - 4 ' " t/-'*l-gq *f_37--.

--

ago fJes.*-; esxMic%cat (> 4 3, -f$* ^-&I - - - 5 - Q

19 J a h ~ G % & , % C I L - L L G, &2r

" j " fi 94 ISe 20 ,, 0

~ ~ a g z e r ^{*.* at,} k k3. ^{4 9} Q ^n@ 51,yO 57,d"

Angle

EX.

RESULTS

Idk3$4ses ' k ; h r ~ u g ; ~ the i;let guidca vases should vary ^as t h e sguaye og

accor&,?g to the above criteria, u s i ~ l g the desig2-i flow rate value as o ba-

was n g t i i n a otrong w&@ at the d@sig;7 ,BOW ;?P&@, f$, is .felt that ^W&C@S

c f r c u ~ n P e r e ~ : ~ & axe raga, Tfxeref ore, ~ ~ o s e deedled sktrvayg %&en at the d a o i g ~ :

sow

rate ars ave~agsd ci~ekaderer:%i&Iy asd assurasd ts v a v oa

2 Wotar PerXorma~ce

-

^Averaged R e a ~ d t ~

. -

%-- - -

- ' '

--

^-=---

The aversze

a0.e.s

crjcfBcie:nt i s Q e t a r n ~ i : ~ e d by ~ n w ~ m e r i c d h;1tegr8-

The varia6:isn sf aperage presBure coe&%cisnt with average aovi

The vazk.i;-ekiar~ of average ?resoak-c cmaici@nt v ~ i t 9 tdp clearance a%

tJi'ee v a r f o ~ ~ Qrsw patee, as shwgxz ^{i t 5} Fi~ure 23) i s @ @ B P to be B T P Q $ ~ C ~ V'd*

aeo plsetsd i x i ;%"iga%ra 6 h8we bwan referred ^$0 coai2?s%-n flaw rates before being eras@ -gloBed i n Figuse ^8, 'r3esugh 6 ~ r z t i ~ ~ the g e s - d t ~ :*ha8iv that

$he p~essure coeBiei@nt drops .:iaarl.jr. $Il~early At$ ir.rcr;s~lltg tip clear-

c8eara:ce is seen to bs ~ r e a g ~ ~ t a% t2ihr" lo-*@st SOVJ and d e c r e a a e ~

meagcre;ne:;ts,

-

= ~ / $ ~ t z

'R ~3~

A o seen i n i p i ~ u r e 9. tilo aV@pa$@

0 0

S c e e o ~ f y oIIe eircw:&cra~atid e t a ~ o x x was s u r v ~ y a d be?k%d t LC rotor,

a small cl;ax~g~ Zn the psaosura zooEic5e~t will m-&ce z IB,XCB cUza,;ig~ ^$23 ef-

112 %vkLc:: &he ve;~s%ices are shed d s n y kke edges of %a sloe ~athsr~r tkwn a$

the t r a i l i r ~ g cdgu. PLmv visnrrlisaBo*- e q ~ r % n ~ e n t o by ~ a i n u ~ " h a v e ahow?

fae%s,

T . ~ B ~JOEQ the $ip cleara2ce ca:? be ei:ought of az %avl?,ia _{e 3} u~%forn%

V ~ Z O C ~ ~ Y &--I t!:e dSrec6on a$ the ^{C ~ O P}~+~.*lxi~'P- ^{~ ~} 5s cazried $hm~kgh b r m ~ ~ the praBs;.trs to snc%feall-, ~ l d s aose;r&f&ly a ~ c h a 2 g o d $or Blade@ o+f amaJB thick- ness, The vePos=fQ ger,>s.i.lae&ar &o $%@ ~ l ~ ~ r d $3

wllere p, a-.d p2 are s b t i c pressures on the pressure a d . suction side 0 4

P

file blade a%zz~q- from, tE%e kip* in i ;nerd ua v a r f d ~ &orz$ the chord,

d=sr~2p.;.eesoz, &his actio'ia te::&s to increase the pressure o ; ~ the p r e s s u r e

3, R ~ d w ~ e f i a$ ~ H a ~ k Irlput

---

'Zhe f a c t ~ ~ ~ @%a$ caaas 2 zedactiasz

o,f

work f~xpuk $Y %gge rafmr due to $1-p e$eara;~ce are:

(I)

911y~icay there ^be no work done by $22~

0"

Lire seduction oi Y J ~ P L %r.j<*:~t given bg the pzi.sssux& ue~sra~ca

J 'if-righ reference ^&Q P i p r e 23$ %& caa be ~k3~721. ,"I& doa-~g y =: 3,

RaAns, D e a l A,, "'Tip Clearance Flow@ i~ 343dd Flaw G ~ n % p r ~ s -

3QFB &36 pumpli4, cds~li~1i~ xnl@$u%e of %ydfc-

dy_la=ic aad Fb",eci:&~ica E n g f n d ~ ~ P Y ~ Y LaBosa$sria o, Report No, 5, Fisi-y Conlrac:~ Hb-orl-012, ~askY9iJrrlcr 1"-4 a~d. BFZrd 9612, [s-J.;;e 1954).

P J ~ U S ~ B ti, ~ ~ ~ a p a a , , u~2:pa &SP,WLL~S L$W R C ~ ~ I O I ~ B P ~ urs ~ ~ P ~ ~ .Par$ HHa

,

maw T ~ r b o " ~ w ~ a ~ h i ? ~ t ~ @ $ ~ Z d S ~ r ~ a i a Iaati@ate 0.f

T~eFfiollkogy, Z-Py4x+adgi:-~~x:fcs axxd ldsc&Waic<a Z:;xglna@r%ag Lab-.

o r a t a x f e ~ , N a q Ca:.ztract Maaar-220$123), NR 097-0010 Rapart ITcj, 6 [Ma,reh 1957j0

i I

( 2 )

1 ^.-

^{I I}

"

I

^{Tq. 25}

^/

^Ra1.26. &,rnpe ^2% man%

,

Eq. 27

/

~ ~ ~ w i ~ l ~ ~ - i

C i r c u m f e r e n t i a l a v e r a g e o f 4 r a d i a l s u r v e y s ⁷

o

Single r a d i a l s u r v e y w i t h c o r r e c t i o n f a c t o r d e t e r m i n e d

f r o m a v e r a g e

a

S i n g l e r a d i a l s u r v e y

w i t h o u t c o r r e c t i o n ¹

W eu

I

0. I 0 . 2 0 . 3

-

A v e r a g e f l o w c o e f f i c i e n t ,

$I

FIG. 5 - A V E R A G E GUIDE VANE PRESSURE L O S S A S A F U N G T I Q N O F AVERAGE F L O W C O E F F I C I E N T

F I G . 6 A V E R A G E P R E S S U R E C O E F F I C I E N T V E R S U S A V E R A G E F L O W C O E F F I C I E N T F O R VARIOUS T I P C L E A R A N C E S

Average flow coefficient

, d,

FIG. 7 AVERAGE WORK C O E F F I C I E N T V E R S U S AVERAGE F L O W C O E F F I C I E N T FOR VARIOUS T I P C L E A R A N C E S

---_

i 1

-

==I- --m- --

- --

- - - C a l c u l a t e d , no scraping - - - C a l c u l a t e d with scraping

0 0.004 0.008 0.012 0.01 6 0.020 0.024

Tip clearance / b l a d e h e i g h t ,

1

F l G . 8 A V E R A G E P R E S S U R E C O E F F I C I E N T A S A F U N C T I O N O F TIP C L E A R A N C E F O R V A R I O U S F L O W R A T E S

0 0 . 3 4 3

A 0 . 4 0 0

0 . 4 5 0 ^---- E x p e r i m e n t a l - 0 0 . 5 0 0

--

Calculated, Eq. 3

A 0 . 5 5 0

_ -

C a l c u l a t e d , Eq. 3 f 9

I ^I I ^I 1

0

'

^{I I}

0 0 . 0 0 4 0.008 0.012 0.01 6 0.020 0.024 Tip clearance / b l a d e height,

k

FIG. 9 AVERAGE WORK COEFFICIENT AS A FUNCTION OF TIP CLEARANCE FOR VARIOUS FLOW RATES

1.0 ^{5 - - - -}

3 A

a

^@

²

^@

Q-:i

⁰

o m

El El

0 . 9

-

^El

W

I

"

>r 0

I

C

I

.

w

- ^{X I}

^I

.- U 0 0 . 0 0 2 5 I

-

^{0 )} I

0 . 8

-

^A 0 . 0 0 6 4

L o @ 0 . 0 1 2 9

I

I

t o a 0 . 0 2 5 4

l x i

1

I

I

I

0 . 7 ^{I I I I I}

0 0. I 0.2 0.3 0.4

-

^{0.5 0.6}

Average flow coefficient

,

FIG. I 0 ROTOR EFFICIENCY AS A FUNCTION OF AVERAGE F L O W COEFFICIENT FOR VARIOUS TIP CLEARANCES

1

0.7. ^{I I 1 I 1 I i}

0 0.004 0.008 0.012 0.016 0.020 0.024 Tip c l e a r a n c e / blade h e i g h t ,

X

FIG. I I ROTOR EFFICIENCY AS A FUNCTION OF TIP C L E A R A N E FOR VARIOUS FLOW RATES

I

I r o 0 6 a a d - O p C , O )

I _I r o ^ob a O Q C n m

a El. a I* ^LC,,%,,

0

d o ; d d d

0 0 a e r l B T

CV

-

0 0 a3 r'- a

- - - ₆

0 0

s

FIG. 16

-

A X I A L V E L O C I T Y S U R V E Y A H E A D O F T H E R O T O R A V E R A G E D O V E R F O U R C I R C U M F E R E N T I A L S T A T I O N S ,

=

0.0025

1.1

1.0

0.9

0.8

0.7

0.6

.

0 0 0

o

0 0 ~ 0 0 0 0 00 0 0 0 0 0 0 0

0 0

-

0

1

⁰

ⁱ

0 0

0 0

1

-

^{0 !}

0

I

0

0 O

I

-

^O

/

_I

0

I

I 8

oi

t i

-

I

-

1 1 I

0.6 0.7 0.8 0.9 I .O

R a d i u s r a t i o

,(

ld -3 • a 4

C C . C 4

. 0 -

c- at;:

4 /4

'iuai31jjao3 poaq j o i o l p a z l l o l o l o ~

4 4

a poaq l o i o j p a z l i o w ~ o ~

- -

-

^{J-'( 0)} _w

-

⁰

a

IX)

- -

0

- -

- 23, 0

0 _- ^{- -.-} -

*

^{a Ow.e--- i- - --- -- - - -}

Q rn

I

h

a . e

*

^{.Bb FJ}

n~ o c ~ r , 3

D C _X. _i ec ^{0 I3 0} _A

0- QCPC) B LL

E rZl

n 1

^{3 5 Cr)} ₂

17 8 ' 0 -

i CK

5 . - G Q

,

^{a Q}

i

sz

>

3 ag n !?$# C.

4 n f 6

i illr

s 4 n

1

^{w-3 4 3 0 LC}

.

i

a ~7 j 3- K

i b- 6,

B

⁰

9 I m2 2 0 ^Cc:

W

s, 130 w I

k-

7 833 m

tl]

ax

^Ls) ₀

ir

BIglij

3

dEf; ^i- < 1 3

t- 2

- 4 0 m ^Z

a

LLJ CE

4 c

ma 5 - 2

a 1) 4 0

L ⁱⁱ

c 1) 40 z .s$a o a

r-

z 9 % ca& 0

a

Z:

L cW.

%'

sea,

4 z

i; ee

C @a

& G

1--

1

3 0 3 0 N

C- 2s iw

2 . a

^-

^.

^{* 3 t3}

L "3. -

Lt

- - -

G

$+

L i u a ~ 3 i j j a o 3 p o a q i o j o ~ p a z l j o l u ~ o ~

/fi /4

' ( u a ! 3 ! j j a o 3 p o a q lolo4 paztlowdoN

e

-0 -'J

-

⁰

m

^{BD k}

rQ '3 9

-

-

-

-

- L2J 0

6 d

-

^-

a

0

z

-

9 _- a

cn

W I-

a

o a 0

cr

0 B e

3

0 Q . 0 0

d LC.

m

O Q e -3

I

rn

_{0 q e a} 0 ^-

0 ^CE

q0.a

" ³

C r

a .a0 0

L L

E 0

E O S e I-

'icp 0

.. oa "a c)e:

. 0 -

8 a0 + 0 Q D

0

% $

OD ⁰ I--

a e .a a ^g)c

cj

*

'9 d z m

0- .

- a *

^cn

tE

0 , 0

E iB, ^{3 bK}

o a m .-

-a 3

D c l o o ^c.3

a

cc I-

0 Q13 Z

W

-

0 am

-

C3

LL

0 - 0 CL

u r n

R h 0 b-l

5 6

d c s

PI

a d - B , d- ^{o g}

a30 dlil C U C B O J ~

x 0 0 - w

6 1 . m ^{0 8 0 0}

==$

o d o o

-I

<

00. 0

a u 0 ^Q

Q + a

0 0 0

-

o ^Q u ^{BPO k I -}

U CJ C i W O

u .,a o

,

^I

'a 0 % B

0 ^{dl N}

f'

-

6

OJ

r3 - 0 o", 00

- -

^-

- a;

3 0' c3

-

LL

4 - /h

' J U ~ ! ~ ! J J ~ O ~ poaq lo(o4 paz!lourlobd

i

I X

'-

Pressure d e f i c ~ e n c y

8

' I i , "Flow s e p a r a t i o n doe to

! ( I

I

I\

1 f l o w e n t e r i n g a s h a r p

I

I\\

e d g e d o r i f i c e

I I

: 1

I 1 \ I

I

I 'w-

R e a t t a c h m e n t

I

I

I

I ' L

DEFICIENCY FROM FLOW INTO A SLOT FIG. 23

-

PRESSURE

FIG 24

-

V E L O C I T Y D I A G R A M SHOWING FLOW ENTERING A N D LEAVING THE ROTOR WITH RELATIONS TO L I F T AND @ R A G

FIG. 3 0 - G R A P H I C A L DETERMI N A T I O N O F BOUlalCikRY L A Y E R O l S P L A G E M E N T T H I C K N E S S

8*

,.

h

0

I

0 . 4 50 Rains' experimentai points

0 0.004 0.008 0.012 0.0 16 0.020 0.024

Tip clearance / blade height

, A

C

--

w

.

. - -v. -.

.g 0.95 ^{\ w}

'+-

, -*--

G I G . 31 COMPARISON OF CALCULATED AND EXPERIMENTAL

ROTOR EFFICIENCY AS A FUNCTiON

OF

TrP CLEARANCE FOR VARIOUS F L O W R A T E S

Y- w

L

0

4-

0.90.

w

a

24 0 C w

1 1._\ -.-

-

^-L.

--- _-v,-

^{- -2-- -+-}_i;;-----

\

'<- -

^-==---

^{- -} - --

- - - _{- -} ^-

--- Experimental

P --

-1.00 _- Calculated

.\- ^{. -}

Calcula t ed with scraping - - - - Rains' model with scraping