Dr. Camilo Fernando Silva Garzon
Numerical Simulation and analytical modeling of thermoacoustic systems
Power generation by combustion is and will remain significant in the next decades. In order to minimize the emission of harmful combustion products and, therefore, counteract detrimental effects on global warming and human health, it is imperative to develop novel techniques for the design of combustion systems. In the case of gas turbines, which are devices of tremendous importance in aircraft propulsion and generation of electricity, modern designs require operation in lean combustion regimes. A proper implementation of lean combustion has been, however, impeded by the recurrent and unpredictable appearance of thermoacoustic instabilities. In spite of the considerable attention that has been given to thermoacoustic instabilities by the combustion community for several decades, this type of instability remains highly unpredictable. Most of the time, combustion instabilities are encountered in later stages of gas turbine development or even commissioning of engines. Therefore, it is essential to develop methodologies to predict thermoacoustic instabilities at the early stages of design. Thermoacoustic instabilities are produced by the two-way coupling between acoustic waves and the fluctuations of unsteady heat release rate. The corresponding study, consequently, is essentially based both on the assessment of the flame response to external acoustic perturbations, and on the investigation of models that quantify the acoustic fluctuations generated by the flame dynamics.
Because combustion instabilities are highly unpredictable, it is necessary to quantify their probability of occurrence:
The quality of the flame response model obtained by System Identification is essential for a reliable estimation of thermoacoustic instabilities.
Since very recently, it is known that acoustic cavity modes are not the only ones excited by the flame:
Compact numerical and analytical modeling of the flame response, which is based on fundamental physical principles, is of great importance in combustion instability studies:
The interaction of acoustic – flame mechanisms encountered in spray flames is considerably more complex that in gaseous flames.
All five projects make use of experimental data for validation, and numerical simulation for fundamental understanding of the corresponding physics. Analytical formulations are aimed specially at projects 3-5, where a rigorous understanding on the physical mechanisms involved is essential.
- Simultaneous identification of transfer functions and combustion noise of a turbulent flame. Journal of Sound and Vibration 422, 2018, 432-452 more… BibTeX
- Uncertainty quantification and sensitivity analysis of thermoacoustic stability with non-intrusive polynomial chaos expansion. Combustion and Flame 189, 2018, 300-310 more… BibTeX
- Direct assessment of the acoustic scattering matrix of a turbulent swirl combustor by combining system identification, large eddy simulation and analytical approaches. Proceedings of ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition, 2018 more… BibTeX
- The contribution of intrinsic thermoacoustic feedback to combustion noise and resonances of a confined turbulent premixed flame. Combustion and Flame 182, 2017, 269-278 more… BibTeX
- Uncertainty quantification of growth rates of thermoacoustic instability by an adjoint Helmholtz solver. Journal of Engineering for Gas Turbines and Power 139 (1), 2017, 011901-1 bis 11 more… BibTeX
- On Entropy Waves Production Across a Premixed Flame. Proceedings of ASME 2016 Turbo Expo: Turbomachinery Technical Conference & Exposition (GT2016-57026), 2016 more… BibTeX
- The Contribution of Intrinsic Thermoacoustic Feedback to Combustion Noise and Resonances of a Confined Turbulent Premixed Flame. Thermoacoustic instabilities in Gas Turbines and Rocket engines, 2016 more… BibTeX
- Uncertainty quantification of growth rates of thermoacoustic instability by an adjoint Helmholtz solver. Proceedings of ASME Turbo Expo 2016, 2016GT2016-57659 more… BibTeX
- Numerical study on intrinsic thermoacoustic instability of a laminar premixed flame. Combustion and Flame 162 (9), 2015, 3370-3378 more… BibTeX
- On the autoregressive behavior of the intrinsic thermoacoustic feedback loop observed in premixed flames. Proceedings of the ICSV22, 2015 more… BibTeX
- Boundary conditions for the computation of thermo-acoustic modes in combustion chambers. AIAA Journal 52 (6), 2014, 1180-1193 more… BibTeX
- A Grey-Box Identification Approach for Thermoacoustic Network Models. Proceedings of the ASME Turbo Expo 2014: Turbine Technical Conference and Exposition, 2014, 1-10 more… BibTeX
- Identification of Sound Sources in Internal ducted Flows: A Large Eddy Simulation -System Identification Approach. 21st International Congress on Sound and Vibration 2014, ICSV 2014, 2014 more… BibTeX
- Causality and intrinsic thermoacoustic instability modes. Proceedings of the 2014 Summer Program, 2014 more… BibTeX
- Towards concurrent identification of flame dynamics and combustion noise of enclosed flames. Proceedings of the 2014 Summer Program, 2014 more… BibTeX
- Combining a Helmholtz solver with the flame describing function to assess combustion instability in a premixed swirled combustor. Combustion and Flame 160 (9), 2013, 1743 - 1754 more… BibTeX
- Prediction of the nonlinear dynamics of a multiple flame combustor by coupling the describing function methodology with a helmholtz solver. Proceedings of the ASME Turbo Expo 2013: Turbine Technical Conference and Exposition, GT 2013, 2013 more… BibTeX
- Signal Generation and its Influence on the Concurrent Identification of Flame Transfer Function and Combustion Noise. EUROMECH Colloquium 546, 2013Combustion Dynamics and Combustion Noise more… BibTeX