graz - metu · graz university of technology erzherzog-johann-university aeroengine research in...

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Institute for Thermal Turbomaschinery and Machine Dynamics

Graz University of TechnologyErzherzog-Johann-University

Aeroengine Research in European Cooperationat Graz University of Technology

Seminar at the Department of Aerospace Engineering

Middle East Technical UniversityAnkara, April 2008

Wolfgang SanzInstitute for Thermal Turbomachinery and Machine Dynamics

Graz University of TechnologyAustria

Graz

Graz University of Technology

7 Faculties9000 students

City: 240.000 inhabitantsCity+Suburbs: 370.000 inhabitants4 Universities with 50.000 students

Institute for Thermal Turbomachineryand Machine Dynamics

2

Students total 9 200of which women 20 %of which foreigners 14 %(30 students from Turkey)

Beginners 1 400

Graduates 1 019Master degrees 590Doctoral degrees 148

Staff total 1 610Academic Staff 980Non-academic Staff 630

Graz University of Technology

Institute for Thermal Turbomachinery and Machine Dynamics

3

Insitute f. Thermal Turbomachinery & Machine Dynamics

Turbine BladeTest Rig

Transonic Turbine

Office LaboratoryWorkshop

11.550 rpm Mach 1,4 2,7 MW shaft power3,3 MW electric power consumption

15 kg/s mass flow (pressure ratio 2,8)

Compressor Station

Organisational structure

4

Metrology used

pressure, temperature

Probes

surface temperature

flow velocity

Particle-Image-VelocimetryLaser-Doppler-Anemometry

density and density fluctuations

Interferometry

Thermography

Wind tunnel insert

Stereo-PIV

Nd:YAG Laser:New Wave GEMINI PIV120 mJ, double cavityPulse duration: 3-5 nsTime between pulses: 0.7 – 1 µs

Cameras:DANTEC HiSense 80C601280 x 1024 pixel sizeMin. inter-frame period: 0.2 µsAF Micro NIKKOR 60/2.8

Light sheet probe

Camera B

Camera A

Window

5

Laser - Doppler - Anemometer

DANTEC Fiber-FlowAr+ laser and Burst SpectrumAnalyser processor units used to record 2 velocity components

Laser Interferometer

Polytec OVD 353

He-Ne laser with OVD 02 velocity decoderused to record integral and local frequencyspectra of densityfluctuations

6

Computational Fluid Dynamics

Pre-processors

Navier-Stokes solver

Post-processors

Mesh generation, ...

Roe-solver, characteristic solver, solver for LES, ...Visualization, evaluation, ...

Vibration and Stress Analysis

•• ObjectiveObjective: : FailureFailure analysisanalysis of a of a ventilatorventilator wheelwheel of 1.5 m of 1.5 m diameterdiameter

7

Graz - Cycle

TTM Participation in EU Projects

2004 2005 2006 2007 2008 2009 2010 2011

Institute for Thermal Turbomachineryand Machine Dynamics

1. M

ay 2

006

NEWAC (297 k€)

1. F

ebru

ary

2004

AIDA (692 k€)

1. J

anua

ry20

05

VITAL (740 k€)

1. F

ebru

ary

2008 DREAM (825 k€)

1. M

ay 2

008

ALFA-BIRD (280 k€)

Aggressive Intermediate DuctAerodynamics for Competitive and Environmentally Friendly Jet Engines

Environmentally FriendlyAeroengine - Noise Measurements

New Aeroengine Core Concepts -Constant Volume Combustion

Validation of Radical EngineArchitecture Systems –Intermediate Duct Aerodynamics

Alternative Fuels and Biofuelsfor Aircraft Development

8

Running out of fossil fuels•••

Introduction

Increasing problem of enviromental pollution

Increasing fuel costs

Reduce fuel consumption

Increasing efficiency

Priority 4 Aeronautics & SpaceSpecific Targeted REsearch Project

AST3-CT-2003-502836Aggressive Intermediate Duct Aerodynamics for Competitive & Environmentally Friendly Jet Engines



Introduction

Aero engines with a further increased bypass ratio

LP turbines of lower speed and larger diameters

The flow from the HP turbine has to be guided to a LP entry at a larger diameter

without any separation

This intermediate turbine duct (ITD) has to be as short as possibleless weight and costs

typical S-shaped duct

A detailed test arrangement under engine representative conditions is necessary

investigation of the flow through such an aggressive (highly diffusing) duct

9

Introduction

Intermediate Compressor Duct

Intermediate Turbine Duct

Guides the flow from the LP to theHP compressor

Guides the flow from the HP to theLP turbine

Introduction

10

Transonic Test Turbine Facility

Exhaust

Air from 3 MW Compressor Station


11


Overhung Rotor Disk

40 - 185 °C

up to 4 bar

up to 22 kg/s

Casing parts split

horizontallyMax. 11550 rpm

2.8MW

800

Test Rig General Arrangement

Stage ADP:1. Pressure Ratio Π: 3.12. Rotational Speed: 11000

rpm3. Power: 1590 kW4. Swirl Angle at Blade

Exit: ~ -15 deg

1. Mach Number at Blade Exit: ~ 0.65

2. Blade Tip Gaps: 1.5% and 2.4% span

Mixing Chamber Exhaust Casing

Duct:1. A2/A1: ~1. 52. Length/Height: ~2

2436

4835

12

AR: ~1. 5, Length/Height: ~2Performance of straight-walled annular-diffuser for inlet boundary layer blockage of approximately 2 %. Cp* and Cp** are the limits for optimum pressure recovery coefficient for a given diffuserL … average wall length, ∆R1 … inlet heightFrom Sovran and Klomp (1967).

Are

ara

tio

Nondimensional Length

Duct Classification and Test Objectives

Understanding of the duct flow near separation aggressive

Understanding of the duct flowwith significant separation

Reduction of duct length by 20%

super-aggressiveSuppress separation by meansof vortex generators

Shape and position suggested/tested bythe technical universities Genova and Chalmers

Overview of the Investigations

3 Configurations C3, C4 and C5

C5 with Vortex Generators (low profile)

C3 represents an integrated concept

C4 duct flow near separation

C5 separated flow

Vortex generator height appr. 20% of boundary layer thickness

Geometry and arrangement proposed

by the Univ. of Genova

Two different Aero design points (ADP’s)

For each ADP two different rotor tip clearances

Axial pos. depends on the positionof separation

Proposal of position by Chalmers

Cascade Testing necessary!

Strut within the DuctNo LP VanesStrut has to provide the following rotor withthe correct inflow

13

Wide Chord Vanes (Strut)Aggressive Duct

AIDA Test Setups

C3

Super-Aggressive Duct

C4C5

AIDA - Results

The Influence of Blade Tip Gap Variation on the Flow Through an Aggressive S-Shaped Intermediate Turbine Duct

Downstream a Transonic Turbine Stage





Presentations held by Andreas Marn and Emil Göttlich

at the ASME IGTI Conference in MontrealMay 2007

14

Test Rig-Tip Clearance

1.5% span 2.4% span

Measurement Techniques

Full area traversing in 2,5,6 planes between rotor and LP Vane

Five-hole-probe measurements conducted for 2 Aerodesign Points

and two rotor gaps

Full area traversing in 2 planes downstream the LP Vane

Full area traversing between HP Vane and rotor

Full area traversing downstream the rotor

LDV measurements conducted for 1 Aerodesign Point

and two rotor gaps

Static Pressure Taps

Boundary layer rakes, Pressure Rakes, Temperature Rakes

Oil flow visualisation

15

Instrumentation

LDV Measurement Grid

u

vα

16

In-house code (LINARS) developed at Institute for Thermal Turbomachinery, Graz

Code specifics:finite volume spatially third order TVD upwind schemefully implicit treatment of the equation system (ADI)second order accurate in timepressure gradient sensitive wall functionsphase-lagged boundary conditionsSpalart and Allmaras turbulence model

Numerical Results - Flow Solver LINARS

Calculation Specifics

• approximately 2,000,000 cells• fillets and the clearances were modeled

17

Unsteady Flow Through ITD

LDV Measurements at Duct Inlet

Velocity [m/s]

Yaw Angle [deg]

Mach Number

18

Turbulent Kinetic Energy

( )22

43 vuk ′+′⋅= ( )222

21 vuw ′+′⋅=′with

Rotor Wakes (TKE)

SSPS

Rotor Wake

19

Vortical Structures

SSPS

A

BC

Rotor Wake

Velocity Distribution

A

BC1

2

SSPS

Rotor Wake

Shock

20

Tip Leakage Flow

Time-space plots at 88 % span

Instrumentation – Five-Hole-Probe

0.2 < Ma < 0.8

-20 < a +20

-16 < g +20

Calibration Range

Probe from RWTH Aachen (IST)

21

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0.3 0.31 0.32 0.33 0.34 0.35 0.36 0.37

pt/pt,inlet

Pass

age

Hei

ght

C 0.8mmC 1.3mmC 1.5%C 2.4%

Duct Inlet-Total Pressure

Significant differencelimited to tip region

Loss coreshifted towardsmid-span

Total pressure loss increased

Pressure loss due to passage vortex

Pressure loss due to passage vortex, tip leakagevortex and scraping vortex

Higher total pressureP.V. up to 30% channelheight

Due to blockage effect of vortices

22

Duct Inlet Mach Number and Yaw Angle

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-50 -40 -30 -20 -10 0 10 20a

Pass

age

Hei

ght

C 1.5%C 2.4%

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.4 0.5 0.6 0.7 0.8 0.9

Ma

Pass

age

Hei

ght

C 0.8mmC 1.3mm

Lower Ma for 2.4% span case

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.22 0.23 0.24 0.25 0.26 0.27 0.28

p/pt,inlet

Pass

age

Hei

ght

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.22 0.23 0.24 0.25 0.26 0.27 0.28

p/pt,inlet

Pass

age

Hei

ght

Static Pressure

Rotor Tip Gap size2.4% span1.5% span

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Static Pressure


0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.22 0.23 0.24 0.25 0.26 0.27 0.28

p/pt,inlet

Pass

age

Hei

ght

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.22 0.23 0.24 0.25 0.26 0.27 0.28

p/pt,inlet

Pass

age

Hei

ght

Pressure Rise

)()(

, CCt

Cnp pp

ppC

−−

=

-0.6

-0.4

-0.2

0

0.2

0.4

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 x/l

Pres

sure

Ris

e C

oeffi

cien

t

1.5% span Casing 2.4% span Casing 1.5% span Hub 2.4% span Hub

C

C1 C3

C5

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0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.3 0.4 0.5 0.6 0.7 0.8 0.9

Ma

Pass

age

Hei

ght

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

0.3 0.4 0.5 0.6 0.7 0.8 0.9

Ma

Pass

age

Hei

ght

Mach Number


Downstream C1 no distinct Ma number minimum can be seen at the hubMa peak at mitspan flattens

Ma number minimum can be seen in every plane

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.28 0.29 0.3 0.31 0.32 0.33 0.34 0.35 0.36 0.37 0.38

pt/pt,inlet

Pass

age

Hei

ght

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.28 0.29 0.3 0.31 0.32 0.33 0.34 0.35 0.36 0.37 0.38

pt/pt,inlet

Pass

age

Hei

ght

Total Pressure


LossCore

Downstream C1 no distinct minimum at the hub in pt can be seenPt peak at mitspan flattens

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0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-45 -40 -35 -30 -25 -20 -15 -10 -5 0 5 10

α

Pass

age

Hei

ght

Yaw Angle

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-45 -40 -35 -30 -25 -20 -15 -10 -5 0 5 10

α

Pass

age

Hei

ght

Pos. swirl


Strong dec. In plane D

Pitch Angle

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-10 -5 0 5 10 15 20 25 30 35 40

γ

Pass

age

Hei

ght

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-10 -5 0 5 10 15 20 25 30 35 40 45

γ

Pass

age

Hei

ght


26

Estimation of Duct Loss

Loss Generation

0

0.5

1

1.5

2

2.5

3

3.5

C-C1 C-C3 C-D

Measurement Plane

Tota

l Pre

ssur

e Lo

ss [%

]

Gap 1.5% span

Gap 2.4% span

100,

,,×

−=Δ

Ct

planelocaltCtt p

ppp

main portion of the loss generated betweenplane C and C1

mixing losses take effect in planes downstream of C1

Measurements Downstream the LP Vane

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Downstream the LP-Vane

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.4 0.5 0.6 0.7

Ma

Pass

age

Hei

ght

EF

Lower Ma

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.4 0.5 0.6 0.7

Ma

Pass

age

Hei

ght

EF

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.29 0.3 0.31 0.32

pt/pt,inlet

Pass

age

Hei

ght

EF

Lower pt

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.29 0.3 0.31 0.32

pt/pt,inlet

Pass

age

Hei

ght

EF

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.23 0.24 0.25 0.26 0.27

p/pt,inlet

Pass

age

Hei

ght

EF

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.23 0.24 0.25 0.26 0.27

p/pt,inlet

Pass

age

Hei

ght

EF

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-55 -50 -45 -40

α

Pass

age

Hei

ght

EF

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-55 -50 -45 -40 -35

αPa

ssag

e H

eigh

t

EF

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-10 0 10 20 30

γ

Pass

age

Hei

ght

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-10 0 10 20 30

γ

Pass

age

Hei

ght

1.5%

spa

n2.

4% s

pan

Conclusions

• This investigation was conducted to show the influence of thetip gap size on the flow through an aggressive ITD close to separation.

• LDV as well as pressure probes were applied

• In plane C the upper 20% of the passage height is affected

• The small changes in the duct inflow are responsible for a different behavior over a large spanwise area further downstream.

• The comparison with the steady CFD simulation shows that the effects of the tip clearance variation were captured precisely.

• The project goal was to create a unique database for flows within high diffusing S-shaped ducts to get more insight to their flow physics and for CFD verification.

28

VITAL

• VITAL … Environmentally Friendly Aero Engine

• Integrated Project within FP 6

• Subtask at Graz University of Technology:

• Building of a test rig for acoustic measurements behind a turbine stage

• Acoustic measurements together with DLR, Germany

Test Facility

Water brakeScroll and Inlet Casing Turbine stage Exit duct with

microphones

29

air flow

Piviotable inlet guide vanes

Turbine Stage

Stator Vanes

air flow

Turbine Stage

30

Rotor Blades

air flow

Turbine Stage

Exit Guide Vanes

air flow

Turbine Stage

31

Test rig - blade rows distance modification

changeable displacement-rings

air flow

Turbine Stage

A, B, C … Measurement planes for Five-Hole Probe

Probe Measurements

32

Acoustic Measurements• Rotatable cylindrical exit duct• 3 microphone plates at inner and outer duct wall

at 3 circumferential positions• 12 microphones per plate

total 72 microphones

DREAM

Research objectives:

• Open rotor contra-rotating engines: more efficient thantraditional high bypass ratio turbofans (better propulsionefficiency), but are noisier

• Novel architectures and structures (e.g. mid-frame structures)

• Active and passive engine systems to reduce vibrations and study active turbine control.

• Alternative fuels

33

Open Rotor

Geared Open Rotor Direct Drive Open Rotor

Source: DREAM

• Open Rotor Architecture needs a mid-frame structure for mounting to aircraft

• Mid-frame structure is based on an intermediate duct with massive struts influence on duct and turbine aerodynamics

• TU Graz: duct aerodynamics between two full turbine stages

• Adaptation of existing AIDA configuration with 1 ½ stage to a 2-stage test rig with duct between a HP and a LP turbine stage

• Combination of AIDA and VITAL test rigs

DREAM

AIDA rig DREAM rig

To waterbreak

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Thank you for your attention!

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graz - metu · graz university of technology erzherzog-johann-university aeroengine research in...

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