21 février 2024
- Study of Thermoacoustic Instabilities using the Lattice Boltzmann Method / PhD Defense Karthik Bhairapurada
Doctorant : Karthik BHAIRAPURADA
Date : le mercredi 21 février 2024 à 14h00 dans l’amphithéâtre du LMA ; 4, impasse Nikola Tesla ; 13013 Marseille
Abstract : In the quest to address global warming, renewable energy has emerged as a critical focus. Yet, the reality of our current energy landscape makes the complete abandonment of combustion technologies unfeasible. Innovations such as 'Lean Burn' combustion and the integration of cleaner fuels like Hydrogen offer a compromise, balancing immediate energy demands with environmental objectives. However, these advancements also introduce significant challenges, especially the heightened risk of thermoacoustic instabilities in combustion systems, which could lead to catastrophic failures.
Traditional experimental methods for studying and mitigating these instabilities are not only prohibitively expensive but also often impractical. Consequently, there is a growing advocacy for the adoption of advanced numerical methods as efficient and cost-effective alternatives. This thesis underscores the potential of one such method, known as the Lattice Boltzmann Method (LBM). LBM is a numerical method renowned for its distinctive algorithmic structure that facilitates linear interactions between adjacent nodes and enables the local evaluation of non-linear terms. These inherent features endow LBM with computational efficiency and low dissipation properties for acoustics transport, making it a promising tool for simulating flame-acoustic interactions and addressing thermoacoustic instabilities.
This research validates the capabilities of LBM in effectively resolving such instabilities. Through foundational assertions of simple flame-acoustic interactions and simulations within narrow channels, the reliability of the method for investigating combustion instabilities across various scenarios is established. Furthermore, the thesis also explores the field of 'Combustion Noise', demonstrating the potential of LBM in investigating sound generation and propagation phenomena, particularly in hydrogen-fueled combustion scenarios. Finally, the robustness and versatility of LBM in handling thermoacoustic instabilities of turbulent reactive flows in complex geometries are demonstrated through the simulation of an aeronautical burner configuration called PRECCINSTA.
Overall, guided by the importance of innovative numerical methods in bridging the gap between current energy needs and long-term environmental sustainability, this thesis underscores the potential of LBM. Through varied investigations, it not only highlights the capabilities of the method but also contributes to a broader understanding of thermoacoustic phenomena across various settings.
Jury
Mr. Pierre BOIVIN Chargé de Recherche, CNRS, France Directeur de thèse
Mr. Bruno DENET Professeur, AMU, France Co-Directeur de thèse
Ms. Françoise BAILLOT Professeure, CORIA, France Rapporteur
Mr. Vadim KURDYUMOV Senior Researcher, CIEMAT, Espagne Rapporteur
Mr. Luc VERVISCH Professeur, CORIA, France Examinateur
Mr. Laurent GICQUEL Senior Researcher, CERFACS, France Examinateur
Mr. Julien FAVIER Professeur, AMU, France Président
