MAE 298 Seminar: The Dynamics of Premixed Flames in Open and Closed Environments

Abstract: The dynamics of freely propagating and confined premixed flames are investigated within the framework of a hydrodynamic theory. In such models, the flame is assumed to be significantly thinner than all other fluid dynamic lengths and conceptualized as a surface that delineates the unburned mixture from the burned combustion products. Freely propagating flames propagate into the fresh mixture under nearly isobaric conditions, but in closed vessels, they propagate into a mixture that is continuously compressed, causing a rise in pressure and temperature that affects the flow field and further modifies the burning rate. The propagation flame speed, determined through the analysis of its internal structure, depends on the stretch rate that measures the flame deformation, and on the pressure rise when applicable. It is modulated by a parameter on the order of the flame thickness that lumps the properties of the combustible mixture and is known as the Markstein length. In this talk, we demonstrate the distinct accomplishments of hydrodynamic models in a wide range of topics, including clear criteria for the onset of hydrodynamic and diffusive-thermal flame instabilities, the nonlinear development beyond the instability threshold encompassing surface morphology and flame propagation speed, as well as aspects of turbulent flames and scaling laws for the turbulent flame speed.

Bio: Moshe Matalon earned his doctorate from Cornell University and held faculty positions at the Polytechnic Institute of New York and Northwestern University before joining the University of Illinois at Urbana-Champaign. His research interests encompass combustion theory, fluid mechanics and applied mathematics. Matalon made substantial and enduring contributions to various domains within combustion science. His work encompasses hydrodynamic theories of premixed flames in both open and closed environments, the concept of flame stretch and the derivation of the well-known flame-speed/flame-stretch relationship, flame instabilities, the structure of diffusion flames for distinct and non-unity Lewis numbers, edge flame stabilization and dynamics, as well as contributions to droplet and solid particle combustion and combustion at the microscale. Matalon has received numerous awards including the distinguished Zel’dovich Gold Medal of the Combustion Institute, the Numa Manson Medal of the Institute for Dynamics of Explosions and Reactive Systems, the AIAA Fluid Dynamics award and the AIAA Pendray Aerospace Literature award. He is fellow of the Combustion Institute, AIAA, IOP and APS. He serves as editor-in-chief of Combustion Theory and Modelling since 2001 and was associate editor of the Journal of Fluid Mechanics from 2008 - 2019.