HOST Turbine Heat Transfer Program Summary - NASA · HOST Turbine Heat Transfer Program Summary ... jet diameter/blade tip cavity depth ... high cycle efficiency,

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NASA Technical Memorandum 100280

HOST Turbine Heat Transfer Program Summary

Herbert J. Gladden and Robert J. Simoneau Lewis Research Center Cleveland, Ohio

[HASA-Ta-100280) HOST T[IEBINE HEAT T8ANSFEB H08-14320 PBOCRAH SUEHABY [NASA) 2 2 p CSCL 2 0 D

Unclas 63/34 0118106

Prepared for the 33rd International Gas Turbine and Aeroengine Congress and Exposition sponsored by the American Society of Mechanical Engineers Amsterdam, The Netherlands, June 5-9, 1988

https://ntrs.nasa.gov/search.jsp?R=19880004938 2018-07-12T19:13:55+00:00Z

HOST TURBINE H E A T TRANSFER PROGRAM SUMMARY

H e r b e r t J . G l a d d e n and R o b e r t J . Simoneau N a t i o n a l A e r o n a u t i c s and Space A d m i n i s t r a t i o n

Lew is R e s e a r c h C e n t e r C l e v e l a n d , O h i o 44135

ABSTRACT

The o b j e c t i v e s o f t h e HOST T u r b i n e H e a t T r a n s f e r s u b p r o j e c t were t o o b t a i n a b e t t e r u n d e r s t a n d i n g o f t h e p h y s i c s o f t h e a e r o t h e r m o d y n a m i c phenomena and t o a s s e s s and i m p r o v e t h e a n a l y t i c a l methods u s e d t o p r e d i c t t h e f l o w and h e a t t r a n s f e r i n h i g h - t e m p e r a t u r e gas t u r b i n e s . A t t h e t i m e t h e HOST p r o j e c t was i n i t i a t e d , an a c r o s s - t h e - b o a r d i m p r o v e m e n t i n t u r b i n e d e s i g n t e c h n o l o g y was n e e d e d . A b u i l d i n g - b l o c k a p p r o a c h was u t i l i z e d and t h e r e s e a r c h r a n g e d from t h e s t u d y o f f u n d a m e n t a l phenomena

w and m o d e l i n g t o e x p e r i m e n t s i n s i m u l a t e d r e a l e n g i n e a) e n v i r o n m e n t s . E x p e r i m e n t a l r e s e a r c h a c c o u n t e d for r-.

m I a p p r o x i m a t e l y 7 5 p e r c e n t o f t h e f u n d i n g w h i l e t h e ana-

l y t i c a l e f f o r t s w e r e a p p r o x i m a t e l y 25 p e r c e n t . A h e a l t h y governmentlindustryluniversity p a r t n e r s h i p , w i t h i n d u s t r y p r o v i d i n g a l m o s t h a l f o f t h e r e s e a r c h , was c r e a t e d t o advance t h e t u r b i n e h e a t t r a n s f e r d e s i g n t e c h n o l o g y base .

NOMENCLATURE

U.

a i r f o i l a x i a l c h o r d

b l a d e t i p gap

a x i a l f l o w speed

j e t d i a m e t e r / b l a d e t i p c a v i t y d e p t h

c o o l a n t c h a n n e l h y d r a u l i c d i a m e t e r

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

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

s t a t o r e x i t Mach number

N u s s e l t number

r e f e r e n c e N u s s e l t number

c o o l a n t p r e s s u r e

gas s t r e a m p r e s s u r e

r a d i u s

s t a t o r e x i t R e y n o l d s number

l o c a l R e y n o l d s number

c o o l a n t t e m p e r a t u r e

gas s t r e a m t e m p e r a t u r e

a i r f o i l t e m p e r a t u r e

t u r b u l e n c e i n t e n s i t y

s u r f a c e d i s t a n c e

S t a n t o n number

r e f e r e n c e S t a n t o n number

gas s t r e a m v e l o c i t y

rotor wheel speed

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

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

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

b l a d e t i p c a v i t y w i d t h

a x i a l l e n g t h

a n g l e b e t w e e n mean v e l o c i t y and m a j o r t i p c a v i t y a x i s

l e n g t h s c a l e

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

1

!NTRODUCT!ON

I m p r o v e d p e r f o r m a n c e o f a i r c r a f t gas t u r b i n e e n g i n e s i s t y p i c a l l y accompan ied b y i n c r e a s e d c y c l e p r e s s u r e r a t i o and c o m b u s t o r e x i t gas t e m p e r a t u r e . The h o t - s e c t i o n components o f t h e s e t u r b o j e t / t u r b o f a n e n g i n e s a r e s u b j e c t e d t o s e v e r e a e r o t h e r m a l l o a d s d u r i n g t h e m i s s i o n f l i g h t p r o f i l e . M e e t i n g t h e d e s i g n g o a l s o f h i g h c y c l e e f f i c i e n c y , i n c r e a s e d d u r a b i l i t y of t h e h o t - s e c t i o n componen ts , and l o w e r o p e r a t i n g c o s t s r e q u i r e s a m u l t i d i s c i p l i n a r y a p p r o a c h . T u r b i n e H e a t T r a n s f e r was one o f t h e s i x , d i s c i p l i n e s a d d r e s s e d i n t h e m u l t i d i s c i - 2 l i n a r y Hot S e c t i o n T e c h n o l o g y (HOST) P r o j e c t .

Ahen t h e HOST P r o j e c t was o r i g i n a l l y b e i n g p l a n n e d , S t e p k a ( l 9 8 0 ) , one o f t h e o r i g i n a t o r s of t h e p r o j e c t , 3 e r f o r m e d an u n c e r t a i n t y a n a l y s i s o n t h e a b i l i t y t o p r e - d i c t t u r b i n e a i r f o i l t e m p e r a t u r e s . He e s t i m a t e d t h a t t h e t h e n c u r r e n t a b i l i t y t o p r e d i c t m e t a l t e m p e r a t u r e i n an o p e r a t i n g e n g i n e was w i t h i n 100 K and t h a t b y t e s t i n g p r o t o t y p e s t h i s c o u l d be r e f i n e d t o w i t h i n 50 K. He a l s o s u g g e s t e d t h a t t h e u n c e r t a i n t y i n h e a t f l u x was o n t h e e x t e r n a l or t h e h o t gas s i d e s u r f a c e o f t h e a i r f o i l was a p r i n c i p l e c o n t r i b u t o r t o t h e i n a b i l i t y t o p r e d i c t m e t a l t e m p e r a t u r e s ; h o w e v e r , b o t h i n t e r n a l and e x t e r n a l s u r f a c e h e a t t r a n s f e r were i m p o r t a n t . These l e v e l s o f u n c e r t a i n t y i n m e t a l t e m p e r a t u r e can c o n t r i b u t e t o a n o r d e r o f m a g n i t u d e u n c e r t a i n t y i n component l i f e .

i l l u s t r a t e d i n F i g . 1 , s h o w i n g t h e i n t r i c a t e i n t e r n a l f l o w passages and t h e v a r i e t y o f h e a t t r a n s f e r mecha- n i s m s a t w o r k . These i n c l u d e : i m p i n g e m e n t c o o l i n g , s e r p e n t i n e passages w i t h t u r b u l a t o r s u r f a c e s , and p i n f i n s , a l l i n v e r y s h o r t ( i . e . , e n t r a n c e l e n g t h ) d i s - t a n c e s and s u b j e c t t o s t r o n g r o t a t i o n a l f o r c e s . I n a d d i t i o n , s i n c e m o s t b l a d e s a r e f i l m c o o l e d , t h e i n t e r - n a l mass b a l a n c e i s a v a r i a b l e . The c o m p l e x i t y o f t h e e x t e r n a l f low f i e l d o v e r t h e t u r b i n e b l a d e i s i l l u s - t r a t e d i n F i g . 2 . H e a t t r a n s f e r i n t h e e x t e r n a l f low f i e l d i s c h a r a c t e r i z e d b y : h i g h R e y n o l d s number f o r c e d c o n v e c t i o n w i t h r o t a t i o n , h i g h f r e e - s t r e a m t u r b u l e n c e , s t r o n g p r e s s u r e and t e m p e r a t u r e g r a d i e n t s , s u r f a c e c u r - v a t u r e , and an u n s t e a d y f low f i e l d . I n a d d i t i o n , and most i m p o r t a n t , t h e i n t e r n a l a n d e x t e r n a l s u r f a c e h e a t t r a n s f e r c o e f f i c i e n t s a r e c o u p l e d t h r o u g h t h e m e t a l w a l l s . I n f a c t , t h e t u r b i n e a i r f o i l i s a v e r y compac t , v e r y c o m p l e x , and v e r y e f f i c i e n t h e a t e x c h a n g e r . T h i s f e a t u r e i s p a r t i c u l a r l y i m p o r t a n t i n a d u r a b i l i t y p r o - g ram, s u c h as HOST, where t h e r e a l f o c u s i s o n t h e t h e r - mal s t r e s s and f a t i g u e o f t h e s t r u c t u r a l e l e m e n t s .

i t was i m p o r t a n t t o d i r e c t r e s e a r c h a t t e n t i o n t o b o t h t h e i n t e r n a l and e x t e r n a l s u r f a c e s o f t h e t u r b i n e a i r f o i 1 .

i p a t i n g d i s c i p l i n e s e l e c t e d i t s own o b j e c t i v e based o n t h e g r e a t e s t need i n t h a t p a r t i c u l a r a r e a , r a t h e r t h a n some common i n t e r d i s c i p l i n a r y g o a l . I n T u r b i n e H e a t T r a n s f e r i t was d e c i d e d , based o n e v a l u a t i o n s o f t h e t y p e p e r f o r m e d b y S t e p k a ( 1 9 8 0 ) , t h a t a n a c r o s s - t h e - b o a r d improvemen t i n t u r b i n e h e a t t r a n s f e r t e c h n o l o g y was needed . A r a t c h e t i n g up o f t h e o v e r a l l t e c h n o l o g y ; a m o v i n g f rom a c o r r e l a t i o n base t o a more a n a l y t i c a l base was i d e n t i f i e d as t h e T u r b i n e H e a t T r a n s f e r Sub- p r o j e c t g o a l . I t was a l s o i d e n t i f i e d t h a t t h e e x i s t i n g d a t a base was i n s u f f i c i e n t t o s u p p o r t t h i s movement and i n c r e a s i n g b o t h t h e s i z e and q u a l i t y o f t h e d a t a base was e s s e n t i a l . I t was f u r t h e r r e c o g n i z e d t h a t HOST a l o n e c o u l d n o t a c h i e v e t h i s g o a l . I t was hoped t h a t HOST c o u l d be a s u f f i c i e n t c a t a l y s t and p r o v i d e a s u f - f i c i e n t f o r u m t o make t h i s g o a l o n e t h a t a l l o f t h e p a r t n e r s ; g o v e r n m e n t , i n d u s t r y and u n i v e r s i t i e s ; w o u l d f i n d o b t a i n a b l e and w o r t h p u r s u i n g .

A t y p i c a l c o o l e d a i r c r a f t gas t u r b i n e b l a d e i s

Thus, i n t h e HOST T u r b i n e H e a t T r a n s f e r S u b p r o j e c t

I n t h e m u l t i d i s c i p l i n a r y HOST P r o j e c t e a c h p a r t i c -

2

T h i s p a p e r o u t l i n e s t h e p r o g r a m d i r e c t e d a t t h e s e g o a l s . The p a p e r w i l l d e l i n e a t e p r o g r e s s t o w a r d s t h e g o a l s b y r e p o r t i n g examp le r e s u l t s from each o f t h e v a r i o u s r e s e a r c h a c t i v i t i e s . I t w i l l summar i ze t h e m a j o r a c c o m p l i s h m e n t s a n d w i l l make some o b s e r v a t i o n s o n f u t u r e n e e d s .

TURBINE HEAT TRANSFER SUBPROJECT

The r e s e a r c h p r o g r a m o f t h e T u r b i n e H e a t T r a n s f e r S u b p r o j e c t was b a s e d o n t h e i d e a t h a t an a c r o s s - t h e - b o a r d i m p r o v e m e n t i n t u r b i n e d e s i g n was needed . I t was a l s o based o n a n o v e r a l l p h i l o s o p h y a t NASA L e w i s R e s e a r c h C e n t e r o f t a k i n g a b u i l d i n g b l o c k a p p r o a c h t o t u r b i n e h e a t t r a n s f e r , as shown i n F i g . 3 . The r e s e a r c h r a n g e d from t h e s t u d y o f f u n d a m e n t a l phenomena and mod- e l i n g t o e x p e r i m e n t s i n r e a l e n g i n e e n v i r o n m e n t s . B o t h e x p e r i m e n t a l a n d a n a l y t i c a l r e s e a r c h were c o n d u c t e d .

R e t u r n i n g t o F i g s . 1 and 2 , t h e r a n g e o f phenomena a d d r e s s e d i n t h e T u r b i n e H e a t T r a n s f e r S u b p r o j e c t a r e i d e n t i f i e d b y numbers and a r r o w s o n t h e s e f i g u r e s . The c o r r e s p o n d i n g r e s e a r c h p rog rams a r e i d e n t i f i e d i n T a b l e s 1 and 2 . One c a n see from t h e s e f i g u r e s t h a t t h e T u r b i n e H e a t T r a n s f e r S u b p r o j e c t c o v e r e d m o s t o f t h e k e y h e a t t r a n s f e r p o i n t s o n t h e t u r b i n e a i r f o i l : f i l m c o o l e d a i r f o i l s , passage c u r v a t u r e , e n d w a l l f l o w s , t r a n - s i t i o n i n g b l a d e b o u n d a r y l a y e r s , t i p r e g i o n s , and f r e e - s t r e a m t u r b u l e n c e o n t h e e x t e r n a l s u r f a c e s . The s u b p r o j e c t i n c l u d e d i m p i n g e m e n t and t u r b u l a t e d s e r p e n - t i n e p a s s a g e s o n t h e i n t e r n a l s u r f a c e s . The p r o g r a m b r o k e some new g r o u n d . An e x p e r i m e n t was c o n d u c t e d , w h i c h o b t a i n e d h e a t t r a n s f e r d a t a o n t h e s u r f a c e s o f t h e a i r f o i l s i n a o n e and o n e - h a l f s t a g e l a r g e low speed r o t a t i n g t u r b i n e . A n o t h e r e x p e r i m e n t a c q u i r e d d a t a o n t h e i n t e r n a l t u r b u l a t e d s e r p e n t i n e p a s s a g e s s u b j e c t t o r o t a t i o n a t e n g i n e c o n d i t i o n l e v e l s . F i n a l l y , vane h e a t t r a n s f e r d a t a w e r e a c q u i r e d i n a r e a l e n g i n e t y p e e n v i - r o n m e n t b e h i n d a n a c t u a l o p e r a t i n g c o m b u s t o r .

Over t h e l i f e o f t h e HOST P r o j e c t a l i t t l e l e s s t h a n 5 . 5 m i l l i o n n e t r e s e a r c h d o l l a r s were i n v e s t e d i n t h e T u r b i n e H e a t T r a n s f e r S u b p r o j e c t . A s shown i n F i g . 4 ( a ) , t h e r e was a h e a l t h y g o v e r n m e n t l i n d u s t r y l u n i v e r s i t y p a r t n e r s h i p w i t h i n d u s t r y p r o v i d i n g a l m o s t h a l f t h e r e s e a r c h e f f o r t . A p p r o x i m a t e l y t h r e e - f o u r t h s o f t h e e f f o r t was e x p e r i m e n t a l , as shown i n F i g . 4 ( b ) . The m a j o r i t y o f e f f o r t e s t a b l i s h e d a l a r g e number o f m a j o r e x p e r i m e n t a l d a t a s e t s . These d a t a s e t s h a v e been w e l l r e c e i v e d a n d a r e e x p e c t e d t o p r o v i d e benchmarks f o r t u r b i n e h e a t t r a n s f e r f o r many y e a r s t o come. The a n a l y s e s c o v e r e d a w i d e r a n g e , i n c l u d i n g a t h r e e - d i m e n s i o n a l N a v i e r - S t o k e s e f f o r t ; h o w e v e r , most o f t h e a n a l y t i c e f f o r t was f o c u s e d o n m o d e l i n g l o c a l phenomena o f k e y i m p o r t a n c e . The scope and r a n g e o f t h e p r o g r a m i s b e s t seen b y e x a m i n i n g r e p r e s e n t a t i v e r e s u l t s .

EXPERIMENTAL DATABASE

The e x p e r i m e n t a l p a r t o f t h e T u r b i n e H e a t T r a n s f e r S u b p r o j e c t c o n s i s t e d of s i x ( 6 ) l a r g e e x p e r i m e n t s a n d t h r e e ( 3 ) o f somewhat more modes t scope and was s t r u c - t u r e d t o a d d r e s s t h e phenomena i d e n t i f i e d i n F i g s . 1 and 2 . T h r e e ( 3 ) o f t h e l a r g e e x p e r i m e n t s were con- d u c t e d i n a s t a t i o n a r y f r a m e o f r e f e r e n c e and t h r e e ( 3 ) were c o n d u c t e d i n a r o t a t i n g f r a m e o f r e f e r e n c e .

S t a t i o n a r y R e f e r e n c e One o f t h e i n i t i a l r e s e a r c h e f f o r t s was t h e s t a t o r

a i r f o i l h e a t t r a n s f e r p r o g r a m p e r f o r m e d a t t h e A l l i s o n Gas T u r b i n e D i v i s i o n ( N e a l y e t a l . , 1983 ; H y l t o n e t a l . , 1983 ; N e a l y e t a l . , 1984; T u r n e r e t a i . , 1985 ; Yang e t a l . , 1 9 8 5 ) . T h i s r e s e a r c h c o n s i s t e d o f d e t e r m i n i n g t h e e f f e c t s o f R e y n o l d s number, t u r b u l e n c e l e v e l , Mach

ORIGINAL PAGE IS OE POOR QUALITY

number. temperature ratio, acceleration, and boundary layer transition on heat transfer coefficients for various airfoil geometries at simulated engine conditions. This research was conducted for nonfilm-cooled airfoils, showerhead film-cooled designs and showerhead/ gill-region film cooling concepts. Typical results of this research are shown in Fig. 5. A typical cascade configuration is shown in the photograph (Fig. 5(a)). Two-dimensional midspan heat transfer coefficients and static pressure distributions were measured on the cen- tral airfoil of the three vane cascade. Nonfilm-cooled clata are snown in Fig. 5(b) where the boundary layer Transition is clearly identified as a function of Reynolds numDer on the suction surface. Figure 5(c) shows the effect on heat tr-ansfer in the downstream recovery region to the addition of showerhead film cooling. Data are presented as a Stanton number reduction. A detrimental effect is noted in the boundary layer transition region of the suction surface to the addition mass at the leading edge. Figure 5(d) shows a strong dependence on "gill-region" film cooling which is con- sistent with experience. However, when combining showerhead with gill-region film cooling more mass addition i s not always better as indicated by the Stanton number reduction data on the pressure surface. This is a very extensive dataset which systematically shows the important effects of modern film cooling schemes on modern airfoils. It went beyond the traditional effective- ness correlations to provide actual heat transfer data. It should provide a valuable baseline for emerging analysis codes.

An investigation of secondary flow phenomena in a 90" curved duct was conducted at the University of Tennessee Space Institute (Crawford et al, 1985). The curved duct was utilized to represent airfoil passage curvature without the complexity of the horseshoe vortex. These data consist of simultaneous three- dimensional mean value and fluctuating components of velocity through the duct and compliment similar data in the literature. A schematic of the test facility and the three-dimensional laser velocimeter are shown in Fig. 6. The first phase of the research examined flows with a relatively thin inlet boundary layer and low free-stream turbulence. The second phase studied a thicker inlet boundary layer and higher free-stream turbulence. Typical experimental results of this research are shown in Fig. 6. The vector plot of cross-flow vel- ocities clearly shows the development o f a vortex in the duct corner near the low pressure surface. The analytical results will be mentioned in the Viscous Flow Analysis section. These data provide a comprehensive benchmark to verify codes at realistic flow conditions.

in the high-pressure facility (Gladden et al., 1985a; Gladden et al., 1985b; Gladden et al., 1987; Hippen- steele et al., 1985). This facility was capable of testing a full-sized single-stage turbine at simulated real engine conditions. The tests, however, were lim- ited to combined combustor/stator experiments. One experiment examined full-coverage film-cooled stator airfoils, while the second experiment utilized some of the advanced instrumentation developed under the instrumentation subproject. A comparison of experimental air- foi} temperatures with temperatures obtained from a typical design system showed substantial differences for the full-coverage, film-cooled airfoils and suggests that models derived from low-temperature experiments are inadequate for "real-engine'' conditions. The advanced instrumentation tests demonstrated the capability and the challenges of measuring heat flux and time-resolved gas temperature fluctuation in a real-engine environment.

Two experiments were also conducted at NASA Lewis

Typical results are shown in Fi;. 7 for thin film thermocouples and the dynamic gas temperature probe tested a simulated real engine condition. A comparison is made between steady state heat flux measurements and those determined from dynamic signal analysis techniques.

study of the physical phenomena that affect heat transfer in turbine airfoil passages. Their recent experimental research has been concerned with high free-stream turbulence intensity and large rurbulence scale that might be representative of combustor exit phenomena. A schematic of their free jet test facility and typical results are shown in Fig. 8. Data are measured on a constant temperature flat plate located at a specified radial and axial distance from the jet exit centerline. These data, presented as Stanton number ratios, indicate that heat transfer augmentation can be as high as 5X at a high value of free-stream turbulence intensity but only 3X i f the length scale i s changed. These results suggest that the designer must know a great deal more about the aerodynamic behavior of the flow field in order t o successfully predict the thermal performance of the turbine components.

Prior to the advent of the HOST program, Arizona State University was pursuing a systematic study of impingement heat transfer with cross-flow characteristic of turbine airfoil cooling schemes. The work was ini- tially sponsored by a NASA Lewis grant but was subse- quently funded by the HOST program. The results of this research are summarized in Florschuetz et ai. (1982a), Florschuetz et al. (1982b), Florschuetz et al. (1982c), Florschuetz et al. (1983). Richards et al. (1984), Florschuetz et a1 (1984), Florschuetz et ai. (1987), Florschuetz et al. (1985), Florschuetz et ai. (1984). In addition to the many geometry variations, this research also investigated the effects of various jet- flow t o crossflow ratios and differences between the jet-flow and the cross-flow temperature. Correlations were developed for both inline rows of impingement jets and staggered arrays of jets but without an initial cross-flow. The effects of cross-flow and temperature differences were then determined relative to the base corre 1 at i ons . Rotating Reference

dynamic and heat transfer measurements were made in the large, low-speed turbine at the United Technologies Research Center (Dring et al., 1987; Dring et al., 1986a; Dring et al., 1986b; Dring et al., 1986c; Blair et al., 1988; Blair et al., 1988). Single-stage data with both high and low-inlet turbulence were taken in phase I. The second phase examined a one and one-half stage turbine and focused on the second vane row. Under phase I11 aerodynamic quantities such as interrow time- averaged and rms values of velocity, flow angle, inlet turbulence, and surface pressure distributions were measured. A photograph of the test facility is shown in Fig. 9. Typical heat transfer data for both the first stator and rotor are also shown. These data show that an increase o f inlet turbulence has a substantial impact on the first stator heat transfer. However, the impact on the rotor heat transfer is minimal. These data are also compared with Stanton numbers calculated by a boundary layer code and the assumption that the boundary layer was either laminar (LAM) or fully turbulent (TURB). on the suction surface of both the stator and the rotor. However, the heat transfer on the pressure surface, especially for the high turbulence case, was generally above even fully turbulent levels on both airfoils. Pressure surfaces have traditionally received less

Stanford University has conducted a systematic

In the rotating reference frame, experimental aero-

These assumptions generally bracketed the data

3 OMGINAL PAGE IS DE POOR QUALITY

a t t e n t i o n t h a n s u c t i o n s u r f a c e s . The h i g h h e a t t r a n s - f e r o n r h e p r e s s u r e s u r f a c e i s n o t r e a d i l y e x p l a i n a b l e and c a l l s f o r a d d i t i o n a l r e s e a r c h , e s p e c i a l l y m o d e l i n g , on p r e s s l r r e s u r f a c e s .

The t i D r e g i o n o f ro to r b l a d e s i s o f t e n a c r i t i c a l r e g i o n and a n a r e a t h a t s u f f e r s s u b s t a n t i a l damage from t h e h i g h t e m p e r a t u r e e n v i r o n m e n t . A r i z o n a S t a t e U n i v e r s i t y has e x p e r i m e n t a l l y m o d e l e d t h e b l a d e t i p c a v i t y r e g i o n and d e t e r m i n e d h e a t t r a n s f e r r a t e s b y a mass t r a n s f e r a n a l o g y w i t h n a p h t h y l e n e (Chyu e t a l . , 1 9 8 7 ) . A s c h e m a t i c o f t h e t e s t i s shown i n F i g . 10.

The b l a d e t i p c a v i t y i s a s t a t i o n a r y model a n d t h e r e l a t i v e v e l o c i t y o f t h e s h r o u d i s r e p r e s e n t e d b y a m o v i n g s u r f a c e a t a s p e c i f i e d " g a p " s p a c i n g from t h e b l a d e . S t a n t o n number r e s u l t s for two d i f f e r e n t c a v i t y a s p e c t r a t i o s a r e a l s o shown i n F i g . 10. The h e a t t r a n s f e r o n t h e s u r f a c e s n e x t t o r h e s h r o u d a r e l i t t l e changed b y t h e a s p e c t r a t i o w h i c h i s n o t s u r p r i s i n g . However , t h e h e a t t r a n s f e r t o t h e f l o o r o f t h e c a v i t y i s i n c r e a s e d s i g n i f i c a n t l y o n t h e d o w n s t r e a m p o r t i o n a t t h e l o w e r a s p e c t r a t i o . Also shown i n t h e f i g u r e i s t h e f l o w a n g l e e f f e c t o n h e a t t r a n s f e r . Because o f t h e a i r - f o i l t u r n i n g a t t h e t i p t h e c a v i t y w i l l be a t d i f f e r e n t a n g l e s of a t t a c k t o t h e mean c r o s s f l o w d i r e c t i o n . The d a t a shows a m i n i m a l e f f e c t a t an a s p e c t r a t i o o f 0 . 9 and a s u b s t a n t i a l e f f e c t a t an a s p e c t r a t i o o f 0 . 2 3 . T h i s d a t a s e t i s r e a l l y q u i t e a new a d d i t i o n t o a t r a d i - t i o n a l l y n e g l e c t e d a r e a and shows t h a t w i t h c a r e f u l d a t a s e t s and a n a l y s e s one can o b t a i n an o p t i m a l d e s i g n f o r t i p c a v i t i e s .

s i d e phenomena. S i n c e t h e h e a t t r a n s f e r phenomena i s d r i v e n b y t h e h o t - g a s s i d e c o n d i t i o n s , i t i s a p p r o p r i a t e t o c o n c e n t r a t e r e s o u r c e s o n t h i s a r e a . However , t h e c o o l a n t - s i d e h e a t t r a n s f e r i s a l s o i m p o r t a n t . The re - f o r e , c o o l a n t p a s s a g e h e a t - t r a n s f e r and f low measure - men ts i n a r o t a t i n g r e f e r e n c e f rame were a l s o o b t a i n e d a t P r a t t & W h i t n e y A i r c r a f t I U n i t e d T e c h n o l o g i e s R e s e a r c h C e n t e r ( K o p p e r , 1984 ; S t u r g e s s e t a l . , 1987 ; L o r d e t a l . , 1 9 8 7 ) . E x p e r i m e n t a l d a t a were o b t a i n e d f o r s m o o t h - w a l l s e r p e n t i n e p a s s a g e s and f o r s e r p e n t i n e pas - sages w i t h skewed and n o r m a l t u r b u l a t o r s . The f low and r o t a t i o n c o n d i t i o n s were t y p i c a l o f t h o s e f o u n d i n a c t u a l e n g i n e s . T h i s was a v e r y r e a l i s t i c e x p e r i m e n t . D a t a f o r b o t h t h e s m o o t h - w a l l a n d skewed t u r b u l a t o r passages a r e shown i n F i g . 11 fo r r a d i a l o u t f l o w , r e p r e - s e n t i n g o n l y a t i n y f r a c t i o n of t h e t o t a l d a t a i n v o l v e d i n t h i s v e r y comp lex f low. B o t h d a t a s e t s a r e shown c o r r e l a t e d w i t h t h e r o t a t i o n number e x c e p t f o r h i g h r o t a t i o n numbers o n t h e h i g h p r e s s u r e s u r f a c e . T h i s i s a n a r e a t h a t r e q u i r e s a d d i t i o n a l r e s e a r c h t o u n d e r s t a n d and model t h e p h y s i c a l phenomena o c c u r r i n g i n t h e s e p a s s a g e s .

ANALYTICAL TOOLS

The p r e c e e d i n g s t u d i e s were f o c u s e d o n t h e h o t - g a s

The a n a l y t i c p a r t s o f t h e t u r b i n e h e a t t r a n s f e r s u b p r o j e c t a r e c h a r a c t e r i z e d b y e f f o r t s t o a d a p t e x i s t - i n g codes and a n a l y s e s t o t u r b i n e h e a t t r a n s f e r . I n '

g e n e r a l , t h e s e codes a n d a n a l y s e s were w e l l e s t a b l i s h e d b e f o r e HOST became i n v o l v e d ; h o w e v e r , t h e a p p l i c a t i o n s were n o t f o r t u r b i n e h e a t t r a n s f e r , and e x t e n s i v e r e v i - s i o n has o f t e n been r e q u i r e d . I n some c a s e s t h e ana- l y t i c and e x p e r i m e n t a l work were p a r t o f t h e same c o n t r a c t

Boundarv L a v e r 4 n a l y s i s

1976) ( w h i c h was d e v e l o D e d o n NASA c o n t r a c t a t S t a n f o r d The STAN5 b o u n d a r y - l a y e r code ( C r a w f o r d e t a l . ,

U n i v e r s i t y i n t h e m i d - 1 9 7 0 ' s ) was m o d i f i e d b y A l l i s o n Gas T u r b i n e D i v i s i o n t o d e f i n e s t a r t i n g p o i n t s and t r a n s i t i o n l e n g t h o f t u r b u l e n t flow t o accommodate t h e i r d a t a , w i t h and w i t h o u t f i l m c o o l i n g , as w e l l as

d a t a i n t h e l i t e r a t u r e . S p e c i f i c r e c o m m e n d a t i o n s a r e made t o i m p r o v e t u r b i n e a i r f o i l h e a t t r a n s f e r m o d e l i n g u t i l i z i n g a b o u n d a r y l a y e r a n a l y s i s . These recommen- d a t i o n s a d d r e s s t h e b o u n d a r y c o n d i t i o n s , t h e i n i t i a l c o n d i t i o n s p e c i f i c a t i o n , i n c l u d i n g b o t h v e l o c i t y a n d t h e r m a l p r o f i l e s , and m o d i f i c a t i o n s o f c o n v e n t i o n a l z e r o o r d e r t u r b u l e n c e m o d e l s . The r e s u l t s o f t h e s e i m p r o v e m e n t s a r e shown i n F i g . 12 where t h e s t a r t o f t r a n s i t i o n and i t s e x t e n t o n t h e s u c t i o n s u r f a c e a r e r e a s o n a b l y w e l l c h a r a c t e r i z e d . F o r t h e c a s e o f shower - head f i l m c o o l i n g , two e m p i r i c a l c o e f f i c i e n t s were u t i - l i z e d t o m o d i f y t h e f r e e - s t r e a m t u r b u l e n c e i n t e n s i t y and t h e gas s t r e a m e n t h a l p y b o u n d a r y c o n d i t i o n s and p e r m i t a r e p r e s e n t a t i v e p r e d i c t i o n o f t h e S t a n t o n number r e d u c - t i o n i n t h e r e c o v e r y r e g i o n . B o u n d a r y l a y e r me thods c a n be u s e d for m i d s p a n a n a l y s i s , however t h e y r e q u i r e a r e a l i s t i c d a t a base t o p r o v i d e t h e c o e f f i c i e n t s needed f o r p r o p e r r e f e r e n c e .

n o l o g i e s R e s e a r c h C e n t e r a s s e s s e d t h e a p p l i c a b i l i t y o f i t s t h r e e - d i m e n s i o n a l b o u n d a r y l a y e r code t o c a l c u l a t e h e a t t r a n s f e r t o t a l p r e s s u r e l o s s and s t r e a m l i n e f low p a t t e r n s i n t u r b i n e p a s s a g e s . The r e s u l t s i n d i c a t e a s t r o n g t h r e e - d i m e n s i o n a l e f f e c t o n a t u r b i n e b l a d e , and a g r e e s q u a l i t a t i v e l y w i t h e x p e r i m e n t a l d a t a . The same code was m o d i f i e d for use as a t w o - d i m e n s i o n a l u n s t e a d y code i n o r d e r t o a n a l y z e t h e r o t o r - s t a t o r i n t e r a c t i o n phenomena ( V a t s a , 1985; A n d e r s o n e t a l . . 1985a ; A n d e r s o n e t a l . . 1985b; Anderson , 1 9 8 5 ~ ) . These codes a l s o needed d a t a as i n p u t .

l e n c e m o d e l i n g , d i r e c t e d s p e c i f i c a l l y a t t h e a i r f o i l i n t h e t u r b i n e e n v i r o n m e n t ' , was c o n d u c t e d a t t h e U n i v e r s i t y o f M i n n e s o t a . A m o d i f i e d form o f t h e Lam-Bremhorst low- Reyno lds -number k -e t u r b u l e n c e model was d e v e l o p e d to p r e d i c t t r a n s i t i o n a l b o u n d a r y l a y e r f l o w s u n d e r c o n d i - t i o n s c h a r a c t e r i s t i c o f gas t u r b i n e b l a d e s ( S c h m i d t e t a l . , 1987) i n c l u d i n g b o t h f r e e - s t r e a m t u r b u l e n c e and p r e s s u r e g r a d i e n t .

b u l e n c e m o d e l i n g t o a p p l y t h e model t o t r a n s i t i o n a l f lows w i t h b o t h f r e e - s t r e a m t u r b u l e n c e and p r e s s u r e g r a d i e n t s . The r e s u l t s o f t h e e f f o r t a r e compared w i t h t h e e x p e r i m e n t a l d a t a o f A l l i s o n Gas T u r b i n e D i v i s i o n i n F i g . 1 3 . The a u g m e n t a t i o n o f h e a t t r a n s f e r on t h e p r e s s u r e s u r f a c e o v e r t h e f u l l y t u r b u l e n t v a l u e i s p r e - d i c t e d r e a s o n a b l y w e l l . I n a d d i t i o n , when an a d v e r s e p r e s s u r e g r a d i e n t c o r r e c t i o n i s u t i l i z e d , t h e s u c t i o n s u r f a c e h e a t t r a n s f e r d a t a i s a l s o p r e d i c t e d r e a s o n a b l y we1 1 .

T h i s was a r e a s o n a b l y good b e g i n n i n g t o e s t a b - l i s h i n g a m e t h o d o l o g y for m o v i n g away from t h e h e a v y dependence o n e m p i r i c a l c o n s t a n t s . A l t h o u g h b o u n d a r y l a y e r me thods w i l l n e v e r s o l v e t h e w h o l e p r o b l e m , t h e y w i l l a l w a y s r e m a i n i m p o r t a n t a n a l y t i c too ls .

I n a n o t h e r b o u n d a r y l a y e r code e f f o r t U n i t e d Tech-

F i n a l l y , a f u n d a m e n t a l s t u d y o n n u m e r i c a l t u r b u -

The p u r p o s e was to e x t e n d p r e v i o u s work o n t u r -

V i s c o u s F l o w A n a l y s i s The t h r e e - d i m e n s i o n a l N a v i e r - S t o k e s TEACH code has

been m o d i f i e d b y P r a t t & W h i t n e y f o r a p p l i c a t i o n t o i n t e r n a l passages a n d t o i n c o r p o r a t e r o t a t i o n a l t e r m s . The m o d i f i e d code has been d e l i v e r e d t o NASA L e w i s and t e s t e d o n some s i m p l e g e o m e t r i c c a s e s . The r e s u l t s o f t h i s e f f o r t i n d i c a t e t h a t t h e code i s q u a l i t a t i v e l y a d e q u a t e f o r s i m p l e g e o m e t r i e s . F o r g e o m e t r i e s o f p r a c t i c a l i n t e r e s t , much work r e m a i n s t o b e done t o b r i n g t h e i n t e r n a l passage c o m p u t a t i o n a l codes u p t o t h e l e v e l of p r o f i c i e n c y o f t h e f r e e - s t r e a m c o d e s . F o r t h e e x t e r n a l a i r f o i l s u r f a c e i m p o r t a n t a n a l y t i c p r o g r e s s i s b e i n g made. By c o n t r a s t , t h e work o n i n t e r n a l passages i s s t i l l p r i m i t i v e . The i n t e r n a l p r o b l e m i s sub- s t a n t i a l l y more c o m p l e x .

code has been u n d e r d e v e l o p m e n t a t S c i e n t i f i c R e s e a r c h A f u l l y e l l i p t i c t h r e e - d i m e n s i o n a l N a v i e r - S t o k e s

4 ORIGINAL PAGE rs OF POOR QUALITY

ORIGINAL PAGE IS OF PO02 QUALITY

A s s o c i a t e s (SRA) f o r many y e a r s . T h i s code was p r i m a r - i l y d i r e c t e d a t i n l e t s and n o z z l e s . S R A , I n c . . has m o d i f i e d t h e code for t u r b i n e a p p l i c a t i o n s ( W e i n b e r g e t a l . , 1 9 8 5 ) . T h i s i n c l u d e s g r i d w o r k fo r t u r b i n e a i r - f o i l s , a d d i n g a n e n e r g y e q u a t i o n and t u r b u l e n c e m o d e l - i n g , and i m p r o v e d u s e r f r i e n d l i n e s s . The h e a t t r a n s f e r p r e d i c t i o n s f rom t h e MINT c o d e a r e shown i n F i g . 14 com- p a r e d t o t h e d a t a from t h e A l l i s o n Gas T u r b i n e r e s e a r c h . The a n a l y t i c a l l e x p e r i m e n t a l d a t a c o m p a r i s o n i s good, however , t h e l o c a t i o n o f b o u n d a r y l a y e r t r a n s i t i o n was s o e c i i i e d f o r t h e a n a l y t i c a l s o l u t i o n .

d e v e l o p e d a t h r e e - o i m e n s i o n a l v i s c o u s f low a n a l y s i s c a p a b i l i t y f o r t h e c u r v e d d u c t e x p e r i m e n t u t i l i z i n g t h e P . D . Thomas code (Thomas. 1173) as a b a s e . Some a n a l - , / t i c a l r e s u l t s f rom t h i s c o d e . a r e shown i n F i g . 6 where a v e c t o r p l o t o f t h e c r o s s - f l o w v e l o c i t i e s a r e compared : v i t h t h e e x p e r i m e n t . I n a d d i t i o n , a s t r e a m s h e e t i s j nown as i t p r o p a g a t e s t h r o u g h t h e d u c t and i s t w i s t e d ;Id s t r e t c h e d . . A d d i t i o n a l c o m p a r i s o n s o f a n a l y s i s and ex.per iment show t h a t t h e t h i n t u r b u l e n t b o u n d a r y l a y e r r e s u l t s o f t h i s e x p e r i m e n t a r e d i f f i c u l t t o c a l c u l a t e w i t h c u r r e n t t u r b u l e n c e m o d e l s .

CONCLUDING REMARKS

The U n i v e r s i t y o f Tennessee Space I n s t i t u t e a l s o

S i n c e t h i s p a p e r i s a n o v e r v i e w o f t h e T u r b i n e H e a t T r a n s f e r a s p e c t s o f t h e HOST p r o g r a m i t has been p r e - s e n t e d as a c a t a l o g i n g and s u m m a r i z i n g o f t h e v a r i o u s a c t i v i t i e s . More i m p o r t a n t l y , t h e HOST p r o g r a m s h o u l d be v i e w e d as a c a t a l y s t b r i n g i n g t o g e t h e r t h e gas t u r - b i n e commun i t y and b u i l d i n g a t e c h n o l o g y momentum t o c a r r y advanced p r o p u l s i o n sys tems i n t o t h e f u t u r e . S p e c i f i c a l l y , t h e HOST T u r b i n e H e a t T r a n s f e r S u b p r o j e c t can p o i n t t o t h e f o l l o w i n g a c c o m p l i s h m e n t s .

1 . The i m p a c t o f a x i a l s p a c i n g a n d i n l e t t u r b u l e n c e o n h e a t t r a n s f e r and a e r o d y n a m i c s t h r o u g h o u t t h e s t a t o r - r o t o r - s t a t o r o f a s t a g e and o n e - h a l f a x i a l t u r b i n e was measured . H i g h - t u r b u l e n c e and p o s t - t r a n s i t i o n a l e f f e c t s o n t h e p r e s s u r e s u r f a c e o f b o t h s t a t o r and rotor c a n cause t h e S t a n t o n number t o b e g r e a t e r t h a n t h e f u l l y t u r b u l e n t v a l u e .

2 . R e y n o l d s number , Mach number, c u r v a t u r e , and w a l l - t o - g a s t e m p e r a t u r e e f f e c t s o n b o u n d a r y l a y e r t r a n s - i t i o n and h e a t t r a n s f e r were d e t e r m i n e d f o r a s t a t o r a i r f o i 1 .

3 . Showerhead and " g i l l - r e g i o n ' ' f i l m - c o o l i n g were shown t o have b o t h b e n e f i c i a l and a d v e r s e e f f e c t s o n t h e r e c o v e r y r e g i o n h e a t t r a n s f e r a t s i m u l a t e d e n g i n e cond i - t i o n s w h i c h depended on s p e c i f i c o p e r a t i n g c o n d i t i o n s .

4 . H e a t T r a n s f e r i n b o t h s m o o t h - w a l l a n d t u r b u l a t e d - w a l l s e r p e n t i n e r o t a t i n g c o o l a n t passages were c o r r e l a t e d w i t h a r o t a t i o n number f o r t h e low- p r e s s u r e s u r f a c e . The h i g h - p r e s s u r e s u r f a c e h e a t t r a n s f e r was n o t w e l l c o r r e l a t e d .

s t r o n g l y d e p e n d e n t o n t h e c a v i t y a s p e c t r a t i o and a n g l e - o f - a t t a c k t o b l a d e t i p f l o w d i r e c t i o n .

i n t e n s i t y f low f i e l d s , s i m u l a t i n g c o m b u s t o r e x i t phenomena, shows a u g m e n t a t i o n r a t e s o f 3X t o 5X depend- i n g o n t h e l e n g t h s c a l e o f t h e t u r b u l e n c e .

and b o u n d a r y c o n d i t i o n s w h i c h a r e a p p l i c a b l e t o t u r b i n e a i r f o i l s . w a s s u c c e s s f u l i n i m p r o v i n g t h e p r e d i c t i o n o f a i r f o i l h e a t t r a n s f e r f o r a w i d e r a n g e o f g e o m e t r i e s u s i n g t h e STAN5 b o u n d a r y l a y e r c o d e .

8 . The Lam-Eremhors t l ow-Reyno lds number k -e t u r - b u l e n c e model was m o d i f i e d t o a l s o i m p r o v e t h e p r e d i c - t i o n s o f a i r f o i l h e a t t r a n s f e r u n d e r t r a n s i t i o n a l f l o w s w i t h b o t h f r e e - s t r e a m t u r b u l e n c e and p r e s s u r e g r a d i e n t s .

5 . B l a d e t i p c a v i t y h e a t t r a n s f e r was shown t o b e

6 . H e a t t r a n s f e r measurements i n h i g h - t u r b u l e n c e

7 . I m p r o v e d d e f i n i t i o n o f t h e i n i t i a l c o n d i t i o n s

9 . A f u l l y e l l i p t i c N a v i e r - S t o k e s code was d e v e l - o p e d f o r t u r b i n e a i r f o i l s and i n c l u d e s t u r b u l e n c e m o d e l - i n g , a n e n e r g y e q u a t i o n and i m p r o v e d u s e r f r i e n d l i n e s s .

F r e q u e n t l y , h e a t t r a n s f e r i s a l i m i t i n g f a c t o r i n t h e p e r f o r m a n c e a n d d u r a b i l i t y o f a n e n g i n e . However , as we c o n t i n u e t o p u r s u e h i g h e r and h i g h e r s p e e d s , a d v a n c i n g t e c h n o l o g y becomes a n i n t e r d i s c i p l i n a r y e f f o r t i n v o l v i n g a e r o t h e r m a l l o a d s d e f i n i t i o n a n d t h e s t r u c - t u r a l r e s p o n s e o f advanced m a t e r i a l s . T h i s i s espe - c i a l l y t r u e f o r h y p e r s o n i c v e h i c l e s where t h e o v e r a l l t h e r m a l management a n d d e s i g n of t h e v e h i c l e and t h e p r o p u l s i o n s y s t e m become a n i n t e g r a t e d i n t e r a c t i v e e n t i t y . We now have , or a r e d e v e l o p i n g , t remendous a n a l y t i c a l c a p a b i l i t i e s w i t h w h i c h one can a t t a c k t h e s e v e r y comp lex t e c h n o l o g y i s s u e s .

LOOK TO THE FUTURE

Many r e c e n t s t u d i e s have been made t o a s s e s s t h e a e r o p r o p u l s i o n t e c h n o l o g y r e q u i r e m e n t s i n t o t h e 2 1 s t c e n t u r y . The c o n s e n s u s seems t o s u g g e s t t h a t s i g n i f - i c a n t t e c h n o l o g y a d v a n c e s a r e r e q u i r e d t o mee t t h e g o a l s of t h e f u t u r e . Whether t h e g o a l s a r e h i g h speed s u s t a i n e d f l i g h t , s i n g l e - s t a g e - t o - o r b i t or s u b s o n i c t r a n s p o r t , t h e i s s u e s f o r t h e d e s i g n e r a r e i m p r o v e d f u e l e f f i c i e n c y , h i g h t h r u s t - t o - w e i g h t , i m p r o v e d component p e r f o r m a n c e w h i l e m a i n t a i n i n g component d u r a b i l i t y and r e d u c e d o p e r a t i n g and m a i n t e n a n c e c o s t s . These i s s u e s w i l l o n l y s e r v e t o i n c r e a s e t h e " o p p o r t u n i t i e s " a v a i l a b l e t o t h e r e s e a r c h e r i n a e r o - t h e r m a l l o a d s a n d s t r u c t u r e s a n a l y s i s . The v e r i f i a b l e p r e d i c t i o n s of u n s t e a d y f l o w f i e l d s w i t h s i g n i f i c a n t s e c o n d a r y f low phenomena and c o u p l e d t h e r m a l l v e l o c i t y p r o f i l e s i s a f e r t i l e r e s e a r c h a r e a . V e r y l i t t l e p r o - g r e s s has been made t o d a t e i n a p p l y i n g CFD t e c h n i q u e s t o t h e i n t r i c a t e and comp lex c o o l a n t c h a n n e l s r e q u i r e d i n t h e h o t - s e c t i o n componen ts . W i t h t h e e x p e c t e d advances i n h i g h - t e m p e r a t u r e m a t e r i a l s t h e components w i t h s i g n i f i c a n t a e r o t h e r m a l l o a d s p r o b l e m s w i l l expand beyond t h e a i r f o i l s and c o m b u s t o r l i n e r s t o s h r o u d s , r i m s , s e a l s , b e a r i n g s , c o m p r e s s o r b l a d i n g , d u c t i n g , n o z z l e s , e t c . The i s s u e s t o be a d d r e s s e d a n d t h e t e c h - n o l o g y advances r e q u i r e d t o p r o v i d e t h e a e r o p r o p u l s i o n sys tems o f t h e 2 1 s t c e n t u r y a r e q u i t e c h a l l e n g i n g .

REFERENCES

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5

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D r i n g , R . P . , B l a i r , M . F . , and J o s l y n , H . D . , 1986a , "The E f f e c t s o f I n l e t T u r b u l e n c e and Rotor S t a t o r I q t e r a c t i o n s o n t h e A e r o d y n a m i c s and H e a t T r a n s f e r o f a L a r g e - S c a l e R o t a t i n g T u r b i n e M o d e l . Vol. 111, H e a t T r a n s f e r D a t a T a b u l a t i o n . 65% A x i a l S p a c i n g , " NASA

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CR-179468.

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D r i n g , R . P . , B l a i r , M . F . , and J o s l y n , H . D . , 1986c , "The E f f e c t s o f I n l e t T u r b u l e n c e and Rotor S t a t o r I n t e r a c t i o n s o n t h e A e r o d y n a m i c s a n d H e a t T r a n s f e r o f a L a r g e - S c a l e R o t a t i n g T u r b i n e M o d e l . Vo l . 11, H e a t T r a n s f e r D a t a T a b u l a t i o n . 15% A x i a l S p a c i n g , " NASA CR-179467.

D r i n g , R . P . , e t a l , 1987, "The E f f e c t s o f I n l e t T u r b u l e n c e and R o t o r / S t a t o r I n t e r a c t i o n s o n t h e A e r o d y n a m i c s and H e a t T r a n s f e r o f a L a r g e - S c a l e R o t a t i n g T u r b i n e M o d e l , V o l . I," NASA CR-4079.

F l o r s c h u e t z , L . W . , and I s o d a , Y . , 1982a , " F l o w D i s t r i b u t i o n s and D i s c h a r g e C o e f f i c i e n t E f f e c t s f o r J e t A r r a y I m p i n g e m e n t W i t h I n i t i a l C r o s s f l o w , " ASME P a p e r 82-GT-156.

F l o r s c h u e t z , L . W . , e t a l , 1982b , " J e t A r r a y I m p i n g e m e n t F l o w D i s t r i b u t i o n s and H e a t T r a n s f e r C h a r a c t e r i s t i c s - E f f e c t s o f I n i t i a l C r o s s f l o w and N o n u n i f o r m A r r a y Geomet ry - Gas T u r b i n e E n g i n e Component C o o l i n g , " NASA CR-3630.

F l o r s c h u e t z , L . W . , M e t z g e r , D. E., and Su, C. C . , 1983, " H e a t T r a n s f e r C h a r a c t e r i s t i c s for J e t A r r a y I m p i n g e m e n t w i t h I n i t i a l C r o s s f l o w , " ASME P a p e r 83-GT-28.

F l o r s c h u e t z , L . W . , and Tseng, H . H . , 1984a, " E f f e c t o f N o n u n i f o r m G e o m e t r i e s o n F l o w D i s t r i b u t i o n s a n d H e a t T r a n s f e r C h a r a c t e r i s t i c s f o r A r r a y s o f I m p i n g i n g J e t s , " ASME Paper 84-GT-156.

F l o r s c h u e t z , L . W . , and M e t z g e r , D. E . , 1984b, " E f f e c t o f I n i t i a l C r o s s f l o w T e m p e r a t u r e o n T u r b i n e C o o l i n g W i t h J e t A r r a y s , " H e a t a n d Mass T r a n s f e r i n R o t a t i n g M a c h i n e r y , D . E . M e t z g e r and N . A f g a n , e d s . , H e m i s p h e r e P u b l i s h i n g C o r p . , W a s h i n g o t n , D .C . , p p . 499-510.

F l o r s c h u e t z . L . W . , and Su, C. C . , 1985 , " H e a t T r a n s f e r C h a r a c t e r i s t i c s W i t h i n a n A r r a y o f I m p i n g i n g J e t s , " NASA CR-3936.

F l o r s c h u e t z , L . W . , and Su, C. C . , 1987 , " R e c o v e r y E f f e c t s o n H e a t T r a n s f e r C h a r a c t e r i s t i c s W i t h i n an A r r a y o f I m p i n g i n g J e t s , " H e a t T r a n s f e r and F l u i d Flow i n R o t a t i n g M a c h i n e r y , W.J. Yang, e d . , Hemisphere P u b l i s h i n g C o r p . , W a s h i n g t o n , D . C . , p p . 375-387.

G l a d d e n , H . J . , Yeh, F . C . , and F r o n e k , D . L . . 1985a , " H e a t T r a n s f e r R e s u l t s and O p e r a t i o n a l C h a r a c t e r i s t i c s o f t h e NASA L e w i s R e s e a r c h C e n t e r Hot S e c t i o n Cascade T e s t F a c i l i t y , " ASME Paper 85-GT-82. (NASA TM-86890) .

G l a d d e n , H . J . , and P r o c t o r , M . P . , 1985b, " T r a n s i e n t T e c h n i q u e for M e a s u r i n g H e a t T r a n s f e r C o e f f i c i e n t s o n S t a t o r A i r f o i l s i n a J e t E n g i n e E n v i r o n m e n t , " A I A A Paper 85 -1471 . (NASA TM-87005).

G l a d d e n , H . J . , Yeh, F . C . , and A u s t i n , P . ? . J r . , 1987 , " C o m p u t a t i o n o f F u l l - C o v e r a g e , F i l m - C o o l e d A i r f o i l T e m p e r a t u r e s b y Two Methods and C o m p a r i s o n W i t h H i g h H e a t F l u x D a t a , " ASME Paper 87-GT-213. (NASA TM-88931) .

H i p p e n s t e e l e , S . A . , R u s s e l l , L . M . , and T o r r e s , F . J . 1985, " L o c a l H e a t - T r a n s f e r Measuremen ts o n a L a r g e Sca le -Mode l T u r b i n e B l a d e A i r f o i l U s i n g a C o m p o s i t e of a H e a t E l e m e n t and L i q u i d C r y s t a l s , " ASME Paper 85-GT-59. (NASA TM-86900) .

H y l t o n , L . D . , e t a l , 1983 , " A n a l y t i c a l and E x p e r i m e n t a l E v a l u a t i o n of t h e H e a t T r a n s f e r D i s t r i b u t i o n Over t h e S u r f a c e s o f T u r b i n e Vanes , " NASA CR-168015.

K o p p e r , F . C . , 1984 , " C o o l a n t Passage H e a t T r a n s f e r W i t h R o t a t i o n . " T u r b i n e E n g i n e Hot S e c t i o n T e c h n o l o g y , NASA

L o r d , W . K . , P i c k e t t , G . F . , S t u r g e s s , G . J . , and W e i n g o l d , H . D . , 1987 , " A p p l i c a t i o n o f CFD Codes t o t h e D e s i g n a n d D e v e l o p m e n t o f P r o p u l s i o n S y s t e m s , " S u p e r c o m p u t i n g i n A e r o s p a c e , NASA CP-2454, P . K u t l e r and H.Yee, e d s . , NASA, W a s h i n g t o n , D . C . , p p . 139-148.

N e a l y , D. A . , e t a l , 1983 , "Measurement o f H e a t T r a n s f e r D i s t r i b u t i o n O v e r t h e S u r f a c e s o f H i g h l y Loaded T u r b i n e N o z z l e G u i d e Vanes , " ASME Paper 83-GT-53, .

N e a l y , D . A . , M i h e l c , M . S . , Hylton, L . D . , and G l a d d e n , H . J . , 1984 , "Measuremen ts o f H e a t T r a n s f e r D i s t r i b u t i o n O v e r t h e S u r f a c e s o f H i g h l y Loaded T u r b i n e N o z z l e G u i d e Vanes , " J o u r n a l o f E n g i n e e r i n g f o r Gas T u r b i n e s a n d Power, V o l . 106 , No. 1 , p p . 149-158.

R i c h a r d s , D . R . , and F l o r s c h u e t z . L . W . . 1984 , " F o r c e d C o n v e c t i o n H e a t T r a n s f e r t o A i r / W a t e r Vapor M i x t u r e s , " NASA CR-3769.

CP-2339, PP. 401 -409 .

S c h m i d t , R . C . , and P a t a n k a r , S . V . , 1987, " P r e d i c t i o n o f T r a n s i t i o n o n a F l a t P l a t e Under t h e I n f l u e n c e o f F r e e - S t r e a m T u r b u l e n c e U s i n g Low-Reynolds-Number Two- E q u a t i o n T u r b u l e n c e M o d e l s , " ASME Paper 87-HT-32.

S t e p k a , F . S . , 1980 , " A n a l y s i s o f U n c e r t a i n t i e s i n T u r b i n e M e t a l T e m p e r a t u r e P r e d i c t i o n s , " NASA TP-1593.

S t u r g e s s , G. J . , and D a t t a , P . , 1987 , " C a l c u l a t i o n o f F l o w D e v e l o p m e n t i n R o t a t i n g Passages f o r C o o l e d Gas T u r b i n e B l a d e s , " Compute rs i n E n g i n e e r i n g - 1987, Vol. 3 , ASME, New York, p p . 149-158.

Thomas, P . D . , 1979 , " N u m e r i c a l Me thod f o r P r e d i c t i n g F l o w C h a r a c t e r i s t i c s and P e r f o r m a n c e o f N o n a x i s y m m e t r i c N o z z l e s T h e o r y , " NASA CR-3147.

6 OIUGINAL PAGE rs .OF POOR QUALITY

OPJGINAL "AGE IS OF POOR QUALITY

Turner, E. R., et al, 1985, "Turbine Vane External Heat Weinberg. B. C., et. al, 1985 "Calculations of Two- Transfer, Vol. I - Analytical and Experimental and Three-Dimensional Transonic Cascade Flow Fields Evaluation of Surface Heat Transfer Distributions With Leading Edge Showerhead Film Cooling," NASA CR-174827.

Vatsa, V. N . , 1985, "A Three-Dimensional Boundary Layer Transfer, Vol. I 1 - Numerical Solutions of the Navier- Analysis Including Heat-Transfer and Blade-Rotation Effects," 3rd Symposium on Numerical and Physical Aspects of Aerodynamic Flows, T. Cebeci, ed., California State University, pp. 10-45 to 10-59,

Using the Navier-Stokes Equations," ASME Paper 85-GT-66.

Yang, R. J., et al, 1985, "Turbine Vane External Heat

Stokes Equations for Two- and Three-Dimensional Turbine Cascades With Heat Transfer," NASA CR-174828.

Figures 1 and 2

TABLE I. - TURBINE HEAT TRANSFER SUBPROJECT SUMMARY

Work element Results Reference

1

1 1

3

5

6

1

10

8

2

7

12

Airfoil with film coolinga

Curved duct

Impingement cooling

Large-scale, high-intensity turbulence

Real engine environment

Provide fundamental experimental data bases with focus on -

Film cooling

Secondary flows

Impingement pattern correlations

Combustor exit simulation

The real environment

Rotating experiments

Large low-speed turbinea

Rotating coolant passage

Tip region simulator

Warm core turbine

Rotor-stator interaction

Coriolis and buoyancy effects

Flow across moving airfoil tip

Vane and blade passage flow map fully scaled

Analyses

STAN5 modif i cat ionsa

Three-dimensional boundary layer

Unsteady boundary 1 ayera

Teach code with rotationa

Low Reynolds number

Mint codeb

Enhance analytic tools for turbine application

Adapt boundary layer code to current airfoil data

Zoom focus on Three-dimensional regions

Account for rotor-stator interaction effects

Three-dimensional Navier-Stokes with rotation terms

Develop turbine airfoil specific turbulence model

Three-dimensional Navier-Stokes applied to turbine airfoil geometry

2 to 6

7

12 to 19

8 to 10

20 to 2 5

27

26

2 to 5

30 to 34

28 to 29

35

36

aExperiment and analysis in the same contract bWork done under two seoarate contracts.

7

v CD-85-16934

FIGURE 1. - TYPICAL COOLED AIRCRAFT GAS TURBINE BLADE. SEE TABLE I FOR DESCRIP- T ION OF NUMBERED FLOW PHENOMENA.

HIGHLY TURBULENT REAL ENGINE FLOW SIMULATION

4 CD-85- 16964

FIGURE 2. - COMPLEX FLOW PHENOMENA I N A TURBINE PASSAGE.

SEE TABLE I FOR DESCRIPTION OF NUMBERED FLOW PHENOMENA.

8

I

FUNDAMENTAL WIND TUNNELS AND FUNDAMENTAL PHENOMENA MODELS TRANSITION, VISUALIZATION,

\ DEVELOPMENT STAT I C CASCADES COLD I ANNULAR AND WARM ANNULAR

ANALYTIC MODELING

I TURBULENCE, F I Lfl COOL I NG I ///////////////////////

FIGURE 3, - BUILDING BLOCK APPROACH TO TURBINE AEROTHERMAL RESEARCH.

CD-85-16940

9

ORIGINAL PAGE IS OF POOR QUALIm

TY

(A> BY LOCATION OF RESEARCH.

EXPER INE

rLYTICAL

(B) BY TYPE OF RESEARCH.

FIGURE 4. - HOST TURBINE HEAT TRANSFER SUBPROJECT DISTRIBUTION OF RESOURCES.

10

C'?IGINA% PAGE IS OF POOR QUALITY

z L v)

L

I-

. .4 E: 2 .2

2 0

B n

2 - .2

5 - . 4 L 0 I-

I- v )

(A) THREE-VANE CASCADE,

0 1.10 t 1.05 - . 4 0 1.02

.2

-

- -

-.----*---8b---wpp*

- -.2

-.4

-

- PRESSURE -

(C) INFLUENCE OF LEADING EDGE FILM-COOLING ON HEAT TRANSFER.

EXIT REYNOLDS NOMINAL RUN CONDITIONS NUMBER

M2 = 0.90 + 1 . 5 1 ~ 1 0 ~ TW/TG = 0.81 1.96X106

Tu = 6.5% o 2 . 4 9 ~ 1 0 ~

Ho = 1135 W/M2/C !i w 1.0

k

2

_.:. ..... .' . . ., " .... +' ....; .... ....... . . 6 ............. y.; . . . . . . . :R?,- a , . . ' . ...... . . . . . . I . : ' v =o .6

u

. . . . . . . . .......... .......,. . 'L.. .. ........... :::- .... .... ....... .2 PRESSURE SUCTION

U

Dz\ W I

z I-

I- 1.0 .8 .6 . 4 .2 0 .2 . 4 .6 .8 1.0

0 9 L

SURFACE DISTANCE, S/ARC

(B) NONFILM-COOLED AIRFOIL HEAT TRANS- FER COEFFICIENTS.

DATA M2 RE2 Pc,Ds/PT Pc,LE/PT TWIT,

BASE .75 2.00E6 0 .75 2.05E6 1.10 1.10 .67 a .74 2.00E6 1.10 1.05 .65 a .75 2.01E6 1.10 1.02 .65

.75 2.00E6 1.10 1.00 .66

100 80 60 40 20

.6

.4

.2

0

-.2

20 40 60 80 100 SURFACE DISTANCE. S/ARC

(D) COMBINED LEADING EDGE AND DOWN- STREAM FILM-COOLING.

FIGURE 5. - GAS-SIDE EXPERIMENTAL HEAT TRANSFER DATA FOR BOTH NON-FILM-COOLED AND FILM COOLED AIRFOILS, ALLISON GAS TURBINE DIVISION.

11

ORIGlNAS PAGE IS OF POOR QUALITY

v CURVED-DUCT F A C I L I T Y

r PARALLEL BEAMS ouipui mion 1 SEPARATOR

3-0 LV OPTICAL SYSTEM

THROUGH DUCT

LOW REYNOLDS NUMBER DATA EXPERIMENTAL RESULTS

FIGURE 6 . - THREE-DIMENSIONAL FLOW-FIELD MEASUREMENTS I N A CURVED DUCT REPRESENTING AN A IRFOIL PASSAGE. UNIVERSITY OF TENNESSEE SPACE INSTITUTE,

12

ORHGPJA-L PACE IS OF POOR QUALITY

WALL TEMPERATURE RESPONSE TO GAS TEMPERATURE RAMP

868

MEASUREMENT = 844 W

Jk -

z w

EXPERIMENTAL TEMPERATURE

$ ' d = 5 a 820 LOCAL HEAT TRANSFER

COEFFICIENTS DETERMINE FROM DYNAMIC SIGNAL ANALYSIS

k-

PRESSURE SURFACL 9 1;:: W

4 1574 0 DYNAMIC SIGNAL ANALYSIS DATA m k - s'd= { STEADY STATE HEAT o FLUX GAGE DATA 2 1486 E w + - STAN5 PREDICTION

1398 1 f 15.3% UNCERTAINTY 0 10 20 30 4 0

0 .2 . 4 .6 .8 1.0 FRACTIONAL DISTANCE FROM

CD-85-17458 LEADING EDGE

FIGURE 7. - HEAT FLUX MEASUREMENTS MADE I N A SIMULATED REAL ENGINE ENVIRONMENT ON STATOR AIRFOILS. LEWIS RESEARCH CENTER.

13

THE FREE JET TURBULENT FREE STREAM

fR X u, U', h , ETC.

/_-

HEAT TRANSFER SURFACE

U, M / S T u SCALE, CM

0.47 60 4

0 I-

0.87 48 9 ? 0.89 63 10 c'

0.82 37 9 0.92 47 8 l+2.9<.53 #lo- 17 0

m

1 I I I 0 100 200 300 400

REX, THOUSANDS

I- A T u = 50%

10-2 L A A A A d

- I-

- VY - 0 T u = 17%

- - -

103 1 o4 105 106 REX

FIGURE 8. - HEAT TRANSFER AUGMENTATION RESULTING FROM HIGH FREE STREAM TURBULENCE AND SCALE. STANFORD UNIVESITY.

14

LARGE SCALE ROTARING R I G 1-1/2 STAGE TURBINE CONFIGURATION F I R S T VANE AND ROTOR CASE REMOVED

H I G H REYNOLD'S NUMBER; 65-PERCENT GAP; C,/U, = 0.78

.008 0 LOW TURB 0 H I G H TURB

-2 -1 0 1 2 -2 -1 0 1 2 S/B,

F IGURE 9. - ROTOR/STATOR INTERACTION AND THE AFFECT ON HEAT TRANSFER OF H I G H AND LOW FREESTREAM TURBULENCE. U N I T E D TECHNOLOGIES RESEARCH CENTER.

1 5

I \ - MOVING SURFACE uw

,012

.008

,004

z 0 t- L a t- v)

.012 I I ! !

.008

.004

n ., 0 2 4

X/D FIGURE 10. - EXPERIMENTAL HEAT TRANSFER RESULTS FOR

A SIMULATED BLADE TIP CAVITY. UNIVERSITY.

ARIZONA STATE

16

ORIGINAL PAGE IS OF POOR QUALITY

?

T

9 m a- m N 7 0

0 nN/nN '0IlWI.l I . l l f N W I . l l lW3H

17

1.0

: 2 .8

u o .6

t z

L L LL W 0 I

E \ W I

. 4

.2

0

PRESSURE SUCTION

I I I I I I I DATA P,/P,

PREDICTION FTU FTG 0 1.10

B

SUCTION

100 80 60 40 20 0 20 40 60 80 100 SURFACE DISTANCE, S/ARC

FIGURE 12. - A MODIFIED STAN-5 BOUNDARY LAYER ANALYSIS IS COMPARED WITH MEASUREMENTS FROM A NON-FILM-COOLED AIRFOIL AND THE SAME A IRFOIL GEOMETRY WITH A SHOWER- HEAD DESIGN. ALLISON GAS TURBINE DIV IS ION.

18

0

0 II

CT W cp

L

I

Q1

5

ii! I- X W

I- z W 0 E W a VI

CD II

W V L W -1 3

3 I-

C(

..

3

L I - 0

c c

V \ r h]

2

H/H 'IN313144303 Ll34SNWtll lW3H 0

19

0 I 1 1.0

.8 2 t;' L . 6

CT .4

.2

!- z

LL

w 0 V

W LL CT) L

CT I-

TYPICAL O-GRID MESH

PRESSURE SIDE SUCTION SIDE I 0

- ANALYSIS

s o Y 1.0 . 8 . 6 .4 .2 0 .2 .4 . 6 .8 1.0

SURFACE D I STANCE, S/ARC

FIGURE 14. - A FULLY E L L I P T I C NAVIER-STOKES SOLUTION IS COMPARED WITH THE SANE EXPERIMENTAL MEASUREMENTS FOUND I N FIGURES 12 AND 13. SCIENTIF IC RESEARCH ASSOC I ATE, I NC .

20

NASA 1. Report No.

NASA TM-100280

Report Documentation Page 2. Government Accession No. 3. Recipient's Catalog No.

4. Title and Subtitle

HOST Turbine Heat Transfer Program Summary

5. Report Date

6. Performing Organization Code I------ 7. Author(s)

Herbert J. Gladden and Robert J. Simoneau 8. Performing Organization Report No.

E-3876

9. Performing Organization Name and Address

National Aeronautics and Space Administration Lewis Research Center C1 eve1 and, Oh i o 441 35-31 91

National Aeronautics and Space Administration Washington, D.C. 20546-0001

2. Sponsoring Agency Name and Address

9. Security Classif. (of this report)

Unclassified

10. Work Unit No.

505-3 1-04

20. Security Classif. (of this page) 21. No of pages 22. Price'

Unclassified I 21 1 A02

13. Type of Report and Period Covered

Technical Memorandum 14. Sponsoring Agency Code

I

I

5. Supplementary Notes

Prepared for the 33rd International Gas Turbine and Aeroengine Congress and Exposition, sponsored by the American Society of Mechanical Engineers, Amsterdam, The Netherlands, June 5-9, 1988.

6. Abstract

The objectives of the HOST Turbine Heat Transfer subproject were to obtain a better understanding of the physics of the aerothermodynamic phenomena and to assess and improve the analytical methods used to predict the flow and heat transfer in high temperature gas turbines. At the time the HOST project was initiated, an across-the-board improvement in turbine design technology was needed. A building-block approach was utilized and the research ranged from the study of fundamental phenomena and modeling to experiments in simulated real engine environments. Experimental research accounted for approximately 75 percent o f the funding while the analytical efforts were approximately 25 percent. A healthy g o v e r n m e n t l i n d u s t r y l u n i v e r s i t y partnership, with industry providing almost half of the research, was created to advance the turbine heat transfer design technology base.

7. Key Words (Suggested by Author(s))

Heat transfer Gas turbines Film cooling

18. Distribution Statement

Unclassified - Unlimited Subject Category 34

~~ ~~ ~ ~~

*For sale by the National Technical Information Service, Springfield, Virginia 221 61 S A FORM 1626 OCT 86

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