modelling of thermoacoustic dynamics in gas turbines ... · changing oscillator’s elements to...
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||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab
Giacomo Bonciolini CAPS Laboratory, MAVT department ETH Zürich
5/8/19 1
Modelling of thermoacoustic dynamics in gas turbines applications
Giacomo Bonciolini
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 2
0 421-1-2-4
Credit: NASA
T Anomaly [°C]vs1950-81
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 3
AnsaldoEnergiaGT36
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 4
AnsaldoEnergiaGT36
CAPS LAB
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 5
GT combustion is studied in laboratory burners
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 6
GT combustion is studied in laboratory burners
ExhaustAir
NG
Plenum
Swirler
Combustion Chamber
Thermocouple
PiezoSensor
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 7
GT combustion is studied in laboratory burners
ExhaustAir
NG
Plenum
Swirler
Combustion ChamberCAPS LAB
Thermoacoustic Instability
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 8
Thermoacoustic coupling first discussed in 18th and 19th century
Doctor Higgins’tube
The pyrophoneLord Rayleigh
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 9
Thermoacoustic coupling stems from heat-sound interaction
FlameTurbulence
Flame perturbation
Heat R.R. fluctuation
Flame SurfaceVariation
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 10
Thermoacoustic coupling stems from heat-sound interaction
Turbulence
Flame perturbation
Heat R.R. fluctuation
Acoustic Oscillations
Source
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 11
Thermoacoustic coupling stems from heat-sound interaction
Turbulence
Flame perturbation
Heat R.R. fluctuation
Acoustic Oscillations
ThermoacousticFeedback
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 12
Thermoacoustic coupling concerns today’s practical systems
Rocketengines
Gas turbines
Aero engines
Structural damages
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 13
Thermoacoustics can be modelled with different levels of detail
Real physicsModel detail
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 14
Thermoacoustics can be modelled with different levels of detail
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 15
Thermoacoustics can be modelled with different levels of detail
Oscillation
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 16
Thermoacoustics can be modelled with different levels of detail
Linear decay/growth
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 17
Thermoacoustics can be modelled with different levels of detail
Flame Non-Linear Response+
Modes coupling
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 18
Thermoacoustics can be modelled with different levels of detail
Effect of turbulence:Random Amplitude
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 19
Changing oscillator’s elements to reproduce different dynamics
Choice #1: Number of modes
Bonciolini, Noiray, “Synchronization of Thermoacoustic Modes in Sequential Combustors”, Journal of Engineering for Gas Turbines and Power (2018).
Experiment – 2 Modes Model 1 Mode
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 20
Changing oscillator’s elements to reproduce different dynamics
Choice #2: Noise color
Noise color ó Spectral content
Blue Noise
+3 dB/oct.
White Noiseconstant
Pink Noise-3 dB/oct.
Experimental
Bonciolini, Boujo, Noiray, “Output-only parameter identification of a colored-noise-driven Van-der-Pol oscillator: Thermoacoustic instabilities as an example”, Physical Review E, (2017).
OK
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 21
Changing oscillator’s elements to reproduce different dynamics
Choice #3: Flame Response Delay
Effective LGR
Bonciolini, Bourquard, Noiray, “Effect of flame response delay and nonlinearity on the modelling of thermoacoustic instabilities”, in preparation
Perturbations - Time delay
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 22
Changing oscillator’s elements to reproduce different dynamics
Choice #4: Nonlinearity
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 23
My PhD
ModelElements
Transients
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 24
Thermoacoustics depends on operating conditions
More air
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 25
Thermoacoustics depends on operating conditions
Ø Bifurcation: dynamics change with one parameter
Ø Transient dynamics through the bifurcation?
?
Unstable Range
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 26
Transient Thermoacoustics is a relevant problem for Gas Turbines
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 27
The transient thermoacoustics trilogy
Experiments and modelling of rate-dependent transition delay in a
stochastic subcritical bifurcation Royal Society Open Science
Effect of wall thermal inertia upon transient thermoacoustic dynamics of
a swirl-stabilized flame Proceedings of the Combustion Institute
Bifurcation Dodge: Avoidance of a Thermoacoustic Instability under
Transient Operation Nonlinear Dynamics
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 28
The dynamics changes for different fuel/air ratios
Stable
Bi-stable
Unstable
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 29
The dynamics changes for different fuel/air ratios
Stable
Bi-stable
Unstable
Subcritical bifurcation
AttractorRepeller
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 30
Transient dynamics is explored by ramping the fuel/air ratio
This cycle is repeated 100 times
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems LabGiacomo Bonciolini
Hopf point
Fold pointQuasi-steady ramps: Hysteresis
5/8/19 31
Transient dynamics is explored by ramping the fuel/air ratio
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab
Fuel/air ratio ramped up&down continuously
Bifurcation delay
5/8/19Giacomo Bonciolini 32
Transient dynamics is explored by ramping the fuel/air ratio
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems LabGiacomo Bonciolini
High-A inertial effects
Bifurcation delay
5/8/19 33
Fuel/air ratio ramped up&down continuously
Transient dynamics is explored by ramping the fuel/air ratio
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems LabGiacomo Bonciolini
Tipping delay depends on the ramp rate
Faster rampàmore delay
5/8/19 34
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 35
Tipping delay is observed experimentally
Stationary
Ramp
No bistability à Hysteresis
Bifurcation delay
1 2 3 4 5 6 7
14 13 12 11 10 9 8
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 36
The model can reproduce the thermoacoustic bifurcation
Envelope
Fokker-Planck eq.
5th order
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 37
Hysteresis
Normalized time
Higher RàMore delay
The model can reproduce the transient dynamics
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 38
Tipping delay is a risk
Control threshold
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 39
Tipping delay is a risk
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab
Tipping delay is a risk
5/8/19Giacomo Bonciolini 40
Eth=1.88
Eth=0.23
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab
Tipping delay is a risk
5/8/19Giacomo Bonciolini 41
5000 realizations of the process
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab
Tipping delay is a risk
5/8/19Giacomo Bonciolini 42
5000 realizations of the process
Higher Ramp Rate
MoreDelay
Higher triggeredLimit cycle Amplitude
More energy released
Slower = Safer
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 43
The transient thermoacoustics trilogy
Experiments and modelling of rate-dependent transition delay in a
stochastic subcritical bifurcation Royal Society Open Science
Effect of wall thermal inertia upon transient thermoacoustic dynamics of
a swirl-stabilized flame Proceedings of the Combustion Institute
Bifurcation Dodge: Avoidance of a Thermoacoustic Instability under
Transient Operation Nonlinear Dynamics
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab Giacomo Bonciolini5/8/19 44
Two consecutive and mirrored supercritical bifurcations
Can we dodgethe bifurcation
by ramping fast?
Stable Stable
Unstable
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 45
Transient dynamics is explored with multiple ramp experiments
ßRamp duration
Stationary reference
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 46
Transient dynamics is explored with multiple ramp experimentsStationary reference
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 47
Transient dynamics is explored with multiple ramp experimentsStationary reference
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 48
Transient statistics depends on the ramp timeStationary reference
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 49
Transient statistics depends on the ramp time
Bifurcation dodge!
Stationary reference
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 50
The model can reproduce the observed transient dynamicsVan der Pol Model
Identification
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 51
The model can be used for preliminary risk estimation
Stationary mapping àOscillation frequency
àGrowth Rate range
àMax Amp à
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 52
The model can be used for preliminary risk estimation
Stationary mapping àOscillation frequency
àGrowth Rate range
àMax Amp à
Explore the system dynamics
in a parametric 2D space
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 53
The model can predict the dodge probability
Drift Diffusion
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 54
The model can predict the dodge probability
Dodge Threshold ó Absorbing BC
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 55
The model can predict the dodge probability
Full dodge
No dodge
Faster = Safer
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 56
A fast growth is harder to dodge
Slow growth Fast growth
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 57
The transient thermoacoustics trilogy
Experiments and modelling of rate-dependent transition delay in a
stochastic subcritical bifurcation Royal Society Open Science
Effect of wall thermal inertia upon transient thermoacoustic dynamics of
a swirl-stabilized flame Proceedings of the Combustion Institute
Bifurcation Dodge: Avoidance of a Thermoacoustic Instability under
Transient Operation Nonlinear Dynamics
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 58
CurrentPrevious
The configuration is modified
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 59
High-amplitudeInstability
The current configuration features as well a double bifurcation
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 60
2000 FPS LIF
Flame topology change is the instability driver
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 61
V-flame
Flame topology change is the instability driver
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab
V-flame
M-flame
5/8/19Giacomo Bonciolini 62
Flame topology change is the instability driver
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 63
Current
Previous
The instability driving mechanism has changed
No flame topologychange
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 64
Wall temperature is the bifurcation parameter
ThermalPower
Wall Temperature
Flame Shape Stability
V
VàM
M
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 65
Thermal inertia defines the transient dynamics
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 66
ThermalPower
Wall Temperature
Flame Shape Stability
V
VàM
MThermalRelaxation time
Thermal inertia defines the transient dynamics
No dodge!
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems LabGiacomo Bonciolini 5/8/19 67
The model can reproduce the observed dynamics
ThermalRelaxation
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems LabGiacomo Bonciolini 5/8/19 68
The model can reproduce the observed dynamics
ThermalRelaxation
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 69
SummaryØ Thermoacoustic bifurcation: operating point ó stability
Ø Many aspects contribute to the system dynamics
Ø Transient thermoacoustics shows peculiar phenomena
Ø Nonlinear oscillator model to understand the physics and perform additional analyses
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab5/8/19Giacomo Bonciolini 70
List of Publications
5.G. Bonciolini, N. Noiray, “Bifurcation Dodge: Avoidance of a Thermoacoustic Instability under Transient Operation”, Nonlinear Dynamics, (2019).
4.G. Bonciolini, D. Ebi, U. Doll, M. Weilenmann, N. Noiray, “Effect of wall thermal inertia upon transient thermoacoustic dynamics of a swirl-stabilized flame”, Proceedings of the Combustion Institute, (2019).
3.G. Bonciolini, N. Noiray, “Synchronization of Thermoacoustic Modes in Sequential Combustors”, Journal of Engineering for Gas Turbines and Power, (2018)
2.G. Bonciolini, D. Ebi, E. Boujo, N. Noiray, “Experiments and modelling of rate-dependent transition delay in a stochastic subcritical bifurcation”, Royal Society open science, (2018).
1.G. Bonciolini, E. Boujo, N. Noiray, “Output-only parameter identification of a colored-noise-driven Van-der-Pol oscillator: Thermoacoustic instabilities as an example”, Physical Review E, (2017).
6.G. Bonciolini, C. Bourquard, N. Noiray, “Effect of flame response delay and nonlinearity on the modelling of thermoacoustic instabilities”, in preparation
Supported by: Swiss NationalScience Foundation
||Department of Mechanical and Process Engineering
CAPS Combustion and Acoustics for Power & Propulsion Systems Lab
Thanks for your attention
Questions
Giacomo Bonciolini – CAPS Lab – ETH Zürich
giacomob@ethz.ch
5/8/19Giacomo Bonciolini 71
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