An Innovation in Film Cooling of the Gas Turbine Blades Applying an Upstream Jet

(1)

JAST. Vol. 9, No. 1, pp 13-26

J

Journal of

A S T

Aerospace Science and Technology

Nomenclature

k P_k

T

L

v2 _!

_t "

f # U_i $ %& " "

u'_i u'_J %&

T'u'_j ' %# S_ij

Re_y ( D_j ) (

V_cf $ %& " _in * $ %&

AR + $ ) , _out - $ %&

T Time t_l Turbulence Time Scale

An Innovation in Film Cooling of Gas Turbine Blades Applying an Upstream Jet

M.R. Salimi

1

_{, M. Taeibi-Rahni}

2

_{, M. Ramezanizadeh}

3

_{, and R. Farhadi-Azar}

4

A new design concept is introduced to control the near-wall integration between the !""# "# ! ! # ! " $ -% "# "" " & ( "" (!"#! "$! # )#((!!!" $ &#" $(! # " #"&!! $! !#!! # " & " using the Reynolds-averaged Navier-Stokes equations closed by the v2_{f - k w turbulence} &$$(!*!+, ./++#"

Keywords0 1 3 # 4 & 5# 6" 7# 8 9#2_{f - k w Turbulence Model}

1. Ph.D Student, Dep't. of Aerospace Eng., Sharif University of #&#=0>?@BC 2. Professor, Dep't. of Aerospace Eng., Sharif University of

Technol-ogy, Tehran, Iran.

?) F G3" )H# K"O )" Eng., Shahid Sattari Aeronautical University of Science & #&#=0WWC . 9 4# K"O )" = # 9 6

Technology, Tehran, Iran.

1 Introduction

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' M.R. Salimi, M. Taeibi-Rahni, M. Ramezanizadeh, and R. Farhadi-Azar

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!4-> An Innovation in Film Cooling of Gas Turbine Blades Applying an Upstream Jet

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C M.R. Salimi, M. Taeibi-Rahni, M. Ramezanizadeh, and R. Farhadi-Azar # +#-!+Q? Z k f

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D An Innovation in Film Cooling of Gas Turbine Blades Applying an Upstream Jet

5 Physical Domain and Boundary Conditions * 4 -+#

5.1 Ordinary Film-Cooling Physical Domain H ! ! -! + %H&

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5.2 Physical Domain of the New Film-Cooling Approach ) ( !! -+4 ! %H Q& ( U / !7( 578: !-(%?Q>&

5.3 Boundary Conditions

H + + +# "

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K M.R. Salimi, M. Taeibi-Rahni, M. Ramezanizadeh, and R. Farhadi-Azar

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6 Grid-Sensitivity and Code-Validation Studies -/ +

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= An Innovation in Film Cooling of Gas Turbine Blades Applying an Upstream Jet

5 Ni U! U(

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Y/

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X/Dj

Z/

Dj

) % !& # @! Q'@ !44 +#+ Y ( Y (+ @ -4 + 4 J %Z =& !"#

Table 2. Number of grid points used in the main jet channel.

Table 3. Number of grid points used in the upstream jet channel.

$" cooling effectiveness.

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Q? M.R. Salimi, M. Taeibi-Rahni, M. Ramezanizadeh, and R. Farhadi-Azar

v2fkZ

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7. Results and Discussion

X/D=3.0.

X/D=5.0.

X/D=8.0.

& '"(""-vided by different turbulence models at Z/D=0.0. Figure 5. Comparison of the stream-wise velocity components

provided by different turbulence models at Z/D=0.0 and X/D=5.0.

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Q An Innovation in Film Cooling of Gas Turbine Blades Applying an Upstream Jet

@ 4 ! + ( ) -% Q>&! !) +-! !+@ ! ! +H !(

7.1 Hydrodynamics of the Flow

P -!+ +++

+ Q'U + 4 !

! !J +

"

a) ) H D

% + & + ! ( + + (/ / ! + % !& +%!&B<8 4 + ! # H K !

)H=4

!) 4 + ! 4 %! &

Figure 7. Stream lines and pressure contours at Z/D=0.0.

Figure 8. Film cooling effectiveness contours **+

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QQ M.R. Salimi, M. Taeibi-Rahni, M. Ramezanizadeh, and R. Farhadi-Azar

b) )! !+(

! ! + + % & !@ H= !#) !

c)

B!#!-+ B!#!-+ !+-H? 4

!Z /Dj 0

4 ~Y*_!w?@

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! + + ! ) (578:# !+ H 4

!Y*_!w4?>

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~Y*_!w;>

! Figure 9. Comparison of the span-wise averaged and centerline

;

< '";" +

Centerline Ef

fectiv

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Q; An Innovation in Film Cooling of Gas Turbine Blades Applying an Upstream Jet

4

7.2 Hot Upstream Jet

) ! !J+ %& %& -!@ !%& !+ %&%& ) ! 4 H;H %&! %&%& Figure '"";"

+

X/D=3

X/D=5

Figure 12. Local temperature distribution at different X/D positions.

X/D=3

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Q' M.R. Salimi, M. Taeibi-Rahni, M. Ramezanizadeh, and R. Farhadi-Azar

!

7.3 Effects of Jets’ Area Ratio

) !! + ) ~4 !(-

.

width

direction

Z

jet

main

The

width

direction

Z

jet

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between hot and the cold upstream jets.

>";;" for three different area ratios.

? ';" different area ratios.

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Q> An Innovation in Film Cooling of Gas Turbine Blades Applying an Upstream Jet

Figure 16. Rise in span-wise averaged effectiveness for three differ-ent area ratios.

7.4 Effects on the Skin Friction Drag (

( +@ HD( -@( [Q?? !

8 Conclusions

) 4) !! ! ! +<8 4 + @! + !-!+ !

!! 4 ?> @ %~Y *! ?& ! @ ( 4-H !

9 References

O 5U L/4$ 7H H 55 <7 8<@5+":) G International Journal of Heat and Mass Transfer8'CUQQQ4Q;>Q??;

Q 7/@ * E4 E G H 5"@ H<G 5 International Journal of Heat and

Fluid Flow8Q=U4DQ??K

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> $ < @4/ <: Z $@ H5G < 5Heat and Mass Transfer. J 8''UK=K=4==KQ??K

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8:<LInternational Journal

of Rotating Machinery 8 ? U > ;'>4 ;>'Q??'

= L Z B 5O U @ < G 5 G H:)))5 5International Journal of Heat and Mass Transfer8'=U>4C==4=;KQ??C

? EO@*G((<$ <H5")+ <International Journal of Heat and Fluid Flow8QKU>=QQ4=;Q??D

<78<4 @5+":)G International Journal of Heat and Mass Transfer 8'CUQQQ4Q;>Q??;

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