development of advanced film cooling technologies for...

STAR GLOBAL CONFERENCE

17 March 2015, San Diego (USA)

Development of Advanced Film Cooling

Technologies for Industrial Gas Turbine

Applications with STAR-CCM+®

Anis Haj Ayed, Karsten Kusterer, Ryozo Tanaka

Anis Haj Ayed

B&B-AGEMA GmbH, Aachen, Germany

engineering your visions

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Contents

Background: Modern Gas Turbine Cooling Design

Development of Advanced Film Cooling Technologies

The Double Jet Film Cooling

The Nekomimi Film Cooling

Design Exploration & Experimental Validation

Summary


3

“Kawasaki L30A”: Application of Modern CFD Tools

World‘s best Industrial GT “Kawasaki L30A”Highest PG efficiency in 30 MW class GT’s


4

“Kawasaki L30A” Overview

30 MWel simple cycle efficiency: 40%

References:

Kawasaki GT line-up (GT2012-68668)

Tanaka, R., Koji, T., Ryu, M., Matsuoka, A., Okuto, A.: Development Of

High Efficient 30MW Class Gas Turbine - The Kawasaki L30A, ASME-

paper GT2012-68668, Copenhagen, Denmark, June 2012.

Taniguchi, T., Tanaka, R., Shinoda, Y., Ryu, M., Moritz, N., Kusterer, K.:

Application of an Optical Pyrometer to Newly Developed Industrial Gas

Turbine, ASME-paper GT2012-68679, Copenhagen, Denmark, June 2012

Successful implementation of

STAR-CCM+ in cooled turbine design

process for:

Design of extensively cooled vanes

and blades for real engine application

and to reach advanced design

specifications.

Acceleration of the design process by

reducing number of test configurations

until product readiness and, thus, to

reduce development costs.

Investigation of innovative cooling

technologies for hot gas components.


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KHI L30 A: Engine Test Facility

Kawasaki L30A: 1st Stage Vane Geometry (Test Configuration)

CHT calculation with STAR-CCM+


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Kawasaki L30A: 1st Stage Vane Geometry (Test Configuration)

main flow inlet

combustion gas

hot gas outlet

cooling inlet 1

pure air

cooling inlet 2

pure air

sealing inlet 2

pure air

sealing inlet 1

pure air


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lowhightemperature

CHT calculation results – pressure side temperature distribution

very good

agreement between

CHT and test data

STAR-CCM+ CHT calculation** circumferential averaged

TIP engine test data** ** fixed position

excellent prediction of internal cooling performance

internally

impingement & convective cooled

internally

convective cooled

film cooling

TIP: Thermal Index Paint


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Why improving film-cooling ?

minimize cooling air consumption maximize efficiency

minimize mixing losses with hot gas maximize efficiency

Minimize solid material temperature maximize lifetime

Understanding film-cooling flow phenomena is

key to improve turbine airfoil design

The Need for Cooling Technology Improvement


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Kidney Vortex Pair

typical lift-off situation

The Problem of Cylindrical Holes: Jet Lift-off Situation


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adf ,film cooling effectiveness

hole exit

Typical lift-off situation

cylindrical hole

Kidney Vortex Pair

The Problem of Cylindrical Holes: Jet Lift-off Situation


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Basic Improvement Concepts

2. Anti-Vortex generation: Formation of vortices inside the cooling jet with opposite

flow direction than the typical Kidney-vortex and, thus, preventing the jet lift-off.

walllateral distribution of

cooling air

lateral distribution of

cooling air

hot gasAnti-counter-

rotating vortices

cooling air cooling air

1. Enhanced cooling air diffusion concepts: Special hole exit shapes and diffusor-

type holes in order to reduce the cooling air momentum at the hole exit and increase

the lateral spreading of cooling air. Shaped holes are state-of-the-art, but special

progressive concepts are under development.

hot gas flow

cooling air flow

lateral spreading


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Combination of two cooling jets from cylindrical holes with lateral injection angle

1 2Anti – Kidney Vortex

adf ,

2

1

1Single jet with

lateral

component

2Single jet with

lateral

component

(mirror case)

1+2

DJFC

1

2

1

2

The Double Jet Film Cooling Technology: DJFC


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Transfer of the DJFC principle to a single hole concept:

(1) Shifting the 2nd hole of the DJFC concept to the same streamwise x-position as the 1st hole

(2) Merging the two holes(3) Replacing the air supplies with one cylindrical supply channel, additional

finalizing of the contour

NEKOMIMI technology („cat ears“)

b=29°

„ear angle“

(1) (2) (3)

The Nekomimi Film Cooling Technology


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Design Exploration


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Film Cooling Effectiveness of different Configurations

ηf,ad


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0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 5 10 15 20 25 30

Fil

m C

oo

lin

g E

ffe

cti

ve

nes

s [

-]

x/D [-]

Shaped Hole

First Nekomimi

Manufac. Nekomimi

Variation 1

Variation 2

Variation 3

Variation 4

Variation 5

Variation 6

variation 4

+ 200 %

Laterally Averaged Film Cooling Effectiveness of different Configurations

first Nekomimishaped


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Jet In Cross Flow Structure Comparison with Shaped Holes


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Advanced NEKOMIMI Cooling: Manufacturing Examples

NEKOMIMI „real“ size manufacturing by EDM in flat plate metal sheet

view along cylinder axis (D=0.5 mm)onview (2 different hole types)

NEKOMIMI sketch for parameter description

Electrical Discharge Machining (EDM) sample


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0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0 5 10 15 20 25 30

Fil

m C

oo

lin

g E

ffe

cti

ve

nes

s [

-]

x/D [-]

Experimental Validation of Film Cooling Effectiveness

shapedfirst Nekomimi

manuf. Nekomimi

variation 3

variation 4

+ 300 %


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Summary

Numerical analyses with STAR-CCM+ helped understand the interaction

between film cooling jet and hot gas stream along gas turbine blades.

This allowed:

development of new, high efficient film cooling technologies

systematic exploration of design potential and alternatives

Increase of Film cooling effectiveness (up to 2.5 times higher) compared

to conventional technologies

development of advanced film cooling technologies for...

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