1
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
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
Transonic Test Turbine Facility
11
Transonic Test Turbine Facility
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
Priority 4 Aeronautics & SpaceSpecific Targeted REsearch Project
AST3-CT-2003-502836Aggressive Intermediate Duct Aerodynamics for Competitive & Environmentally Friendly Jet Engines
Priority 4 Aeronautics & SpaceSpecific Targeted REsearch Project
AST3-CT-2003-502836Aggressive Intermediate Duct Aerodynamics for Competitive & Environmentally Friendly Jet Engines
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
23
Static Pressure
Rotor Tip Gap size2.4% span1.5% span
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
24
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
Rotor Tip Gap size2.4% span1.5% span
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
Rotor Tip Gap size2.4% span1.5% span
LossCore
Downstream C1 no distinct minimum at the hub in pt can be seenPt peak at mitspan flattens
25
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
Rotor Tip Gap size2.4% span1.5% span
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
Rotor Tip Gap size2.4% span1.5% span
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
27
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
34
Thank you for your attention!
The End