ICLEAC Survey Presentation I nstability C ontrol of L ow E mission A ero-Engine C ombustors

1. ICLEAC Survey PresentationInstability Control of Low Emission Aero-Engine Combustors 4 year program started March 1 2000 G4RD-CT-2000-0215 R&T project within the 5th Framework program of the European Union: Presented by: L. Hernandez Turbomeca

2. ICLEAC Survey PresentationInstability Control of Low Emission Aero-Engine Combustors Agenda Partners Mission Organisation Experiments and Measurements Calculations Exploitation and Dissemination Questions

3. ICLEAC Partners Turbomeca F MTU D Rolls-Royce Deutschland D Snecma F Rolls-Royce UK AVIO S.p.A. I QINETIQ UK CERFACS F CNRS/DR5/EM2C F Cranfield University UK Karlsruhe University - EBI D Munich University - TDM D Genova University - DIMSET I UCAM-DENG UK

4. ICLEAC Mission Low Emissions Combustion Instabilities • Treatment of CI today: a posteriori • expensive and time consuming • re-design • tests • Objective: being able to deal with the problem a priori • Concept phase • Design Rules • Low Order Models • Development phase • Heavy CFD methods: URANS* and LES* * Unsteady Reynolds Averaged Navier Stokes * Large Eddy Simulation

5. ICLEAC Mission • Measurements • Injector Aerodynamics and spray databases (steady and unsteady) • Flame Transfer Functions (FTF) in simple and engine like sector rigs • Generic and real engine geometry thermo acoustics and mixing • Calculations • FTF calculated by URANS and LES • URANS and LES development • Tools • Design rules • Low Order Model (LOM) • URANS and LES

6. ICLEAC Organisation 5 Work Packages • WP1 Management and exploitation • WP2 Unsteady behaviour of Fluid-dynamic LP*/LPP* injection systems • WP3 Measurement of Transfer Functions • WP4 Combustion Instabilities Prediction • WP5 Advanced 2 and 3D diagnostics on combustors 4 year program started March 1 2000 • Final report April 2004 * Lean Premixed * Lean Pre-vaporised Premixed

7. ICLEAC Experiments and Measurements Loudspeakers ‘2D’ atmospheric combustion rig • ambient air temperature inlet • acoustic excitation • modular design • Optical access • PLIF*, Chemiluminescence (OH, CH, C2 radicals) • FTF derivation Microphones Adiabatic Walls Optical Access Hot Wire FUEL INLET * Planer Laser Induced Fluorescence

8. ICLEAC Experiments and Measurements Atmospheric Injector Spray Rig • Optical access • Acoustic excitation • PDA* and LSD* for droplet size, velocity, and concentration measurement in dense sprays • Spray FTF derivation * Phase Doppler Anemometry * Laser Sheet Drop sizing

9. ICLEAC Experiments and Measurements Injector spray test rig • 3 bar • 300-500 K • Acoustic excitation • Optical access • PDA and LSD for droplet size, velocity, and concentration measurement in dense sprays • Spray FTF derivation

10. ICLEAC Experiments and Measurements Large scale injector test rig • Atmospheric • Acoustic excitation • Optical access • LDV*, PIV* • Derivation of 3D velocity field and turbulence * Laser Doppler Velocimetry * Particle Imaging Velocimetry

11. ICLEAC Experiments and Measurements Atmospheric Combustion Rig • T3 770 K • Acoustic excitation • Optical access • OHChemiluminescence • FTF derivation

12. ICLEAC Experiments and Measurements Atmospheric Combustion Rig • T3 800 K • Acoustic excitation • Optical access • PIV, Mie scattering, OHChemiluminescence • Derivation of flow/spray field and FTF

13. ICLEAC Experiments and Measurements High Pressure Combustion Rig • P3 40 bar • T3 800 K • Acoustic excitation • Optical access • PIV, OH Chemiluminescence

14. Pressure measurement Pressure casing LPP Burner CH sampling probe Airflow Silencer Combustor Internal ductwork Variable frequency Siren ICLEAC Experiments and Measurements Atmospheric & High Pressure Combustion Rig • P3 15 bar • T3 800 K • Acoustic excitation • FTF derivation from fast response pressure measurements and CH Chemiluminescence

15. ICLEAC Calculations Low-Order Model • Linear model for combustion instability • Gives frequency and stability predictions • Fast enough to be used at design stage

16. ICLEAC Calculations CFD applied to rumble • Mechanism of self-excited oscillation • Identification of flame transfer function • Integration of CFD and low-order models Pressure Time

17. Exploitation and DisseminationRR-UK & RRD • Single sector test rigs • atmospheric • low pressure < 3 bar • intermediate pressure < 15 bar • Flame characterization • Flame transfer functions • Spray transfer functions • LPP modules • delay time • effective area • Air blast burners CRANFIELD / QINETIQ / TD-Munich • CFD simulations • 2D & 3D geometries • numerical FTF • self-excitation • LOM • 1D geometry • implementation of FTF • validation UCAM ICLEAC • Multi-Link Flow Network • in-house application • integration of LOM • validation • CFD simulations • in-house application • best practice • validation RR-UK large engines RRD medium engines

18. Exploitation and Dissemination ExampleLOM results of RB211 DLE industrial combustion system Combustor Mode Unstable Mode Frequency x (m)

19. Exploitation and DisseminationAVIO S.p.A • Laboratory • LPP double swirler injector of AVIO design • large scale model • same Re number • original and modified geometries • Measurement techniques • 3D LDV • hot-wire anemometry • PIV • Unsteady aerodynamic investigation • Time averaged and ensemble averaged flow field • Reynolds stress distributions • unsteady phenomena detection • data sets for time-dependent N.S. and RANS code assessment UNIGE-DIMSET: Experimental activities ICLEAC UNIGE-DIMSET: Numerical activities • Unsteady CFD Solver NastComb: • in-house development & validation • advanced turbulence model • reactive prediction (detailed) • radiation modelling • Analysis mode (large scale premixer): • comparison of flow fields and unstable behaviour • critical modes detection • parametric optimisation • Design mode (Real LPP prototype): • preheated 2-phase behaviour • fully reactive conditions • Transient Performance Method (CFD based) AVIO S.p.A URANS Transient Performance Method (TPM) applied to gas turbine combustor development • LPP double swirler injector design • RANS code for design and analysis validation

20. Exploitation and Dissemination Example

21. Exploitation and DisseminationTurbomeca & SNECMA • Laboratory rig • non-premixed • turbulent burner • Measurements • PIV • OH chem. • Hot wire anemometry • Flame Characterisation • Transfer functions • velocity profiles • visualisation, ... EM2C LES modelling results LES model development ICLEAC CERFACS LES modelling applied to gas turbine combustor development SNECMA Turbomeca

22. Transverse cuts coloured by the propane consumption rate Propane iso-surface (YC3H8=0.06 stoichiometric value) coloured by the temperature Velocity field Exploitation and Dissemination ExampleLES calculation of CNRS/EM2C 2D burner

23. Exploitation and Dissemination ExampleLES calculation of CNRS/EM2C 2D burner Simulation time 21ms ( one flow-through time) Movie of forced case

24. Questions

25. Acronyms

26. ICLEAC Organisation WP2 : isothermal experiments on injection systems WP3 : transfer functions on combustors - effect of damping technologies WP4 : development of simulation methods WP5 : detailed measurements on combustors In each Work package we have two types of hardware that are investigated : • generic / academic hardware • real scale / Low Emission Aero Engine hardware.

27. ICLEAC Experiments and Measurements Atmospheric Combustion Rig • T3 650 K • Optical access • Acoustic excitation • Dynamic pressure, CH Chemiluminescence • FTF derivation

28. ICLEAC Experiments and Measurements High Pressure Combustion Rig • P3 15 bar • T3 800 K • Acoustic excitation • Dynamic pressure, CH Chemiluminescence • FTF derivation

29. ICLEAC Mission • To understand fundamental mechanisms leading to Combustion Instabilities in Aero Engine Low Emission Combustors. This includes the elaboration of comprehensive databases on academic flames and real combustor flames used both for analysis and code validation • To develop and validate predictive tools on generic and real Low Emission combustors also used in other programmes. This includes RANS and LES methods as well as a low order model (TALON) that is delivered to the partners during the last year of the programme • To define and validate design rules for Low Emission Combustors for Aero Engines to avoid/reduce combustion instabilities. Includes correlations between combustor geometries, and oscillation frequencies / amplitudes.