POROLEAF · POROus media: Life and dEath of their wAves and Flames

Turbulent combustion of fossil fuel remains an important source of energy creation and propulsion worldwide, generating pollutant emissions endangering both human health and climate. A major factor inhibiting the mitigation of emissions pertains to combustion instabilities, i.e.: large pressure oscillations resulting from a coupling between unsteady combustion and pressure waves. Carrying out the combustion within porous inert media holds great promise for lean combustion, owing notably to a strong heat recirculation effect occurring inside them. Despite the recognition that porous materials are natural wave absorbers, very little has been studied so far regarding the potential synergy between combustion instabilities and porous media. POROLEAF aims to pioneer the field of research residing at the intersection between the disciplines of waves, turbulent combustion, and porous media. A new set of scientific challenges will be introduced, related to the complex flow physics involved in porous media combustion, as well as the difficulty of accessing the physical fields within the pore matrix. To tackle these challenges, I will build on the skills developed during my thesis in the characterization of porous media microstructure, as well as recent advances in 3D printing technology for heat resistant materials, to create porous samples allowing optical access. This will pioneer the way for a new set of state-of-the-art experiments. I aim to leverage decades of previous work in combustion instabilities and focus on the new behaviors introduced by porous media. In particular, the effects of turbulence, entropy, vaporization, and flame dynamics will need to be re-evaluated in light of porous media interactions. The improved knowledge of these principles will enable unprecedented understanding of the influence of porous media properties on the nonlinear flame response. This will directly assist in the design of cleaner and more stable combustion processes.