Abstract
Premixed flame dynamics within closed vessels are subject to unique physical mechanisms distinct from those of freely propagating flames that evolve under near-isobaric conditions. The rise in vessel pressure and adiabatic gas compression increases flame speed and temperature while reducing flame thickness, profoundly influencing flame stability. We numerically investigate the onset and subsequent nonlinear evolution of the intrinsic Darrieus-Landau flame instability in the context of a recently derived hydrodynamic theory of flames in closed vessels. A hybrid embedded manifold/Navier-Stokes numerical methodology is developed and employed to address multi-dimensional flame propagation within enclosures. This talk discusses the stability of flames in two canonical configurations: planar flames in closed rectangular channels and outwardly expanding cylindrical flames within closed cylinders. Numerical simulations reveal the effect of the heat released at the flame, physico-chemical properties of the combustible mixture and vessel size on the evolution of flame instabilities. Utilizing theory and computations, these results provide valuable insights into the dynamics of flames within enclosures with application to experimental flame speed measurements and engineering applications such as combustors and engines.
About the Speaker
Gautham is a doctoral candidate in the department of Mechanical Science and Engineering at the University of Illinois Urbana-Champaign, working in the Combustion Theory and Modelling Lab. His research interests include flame instabilities, numerical methods for reactive flows and asymptotic analysis of multi-scale problems. His doctoral work focuses on the numerical simulation of premixed flame dynamics with an emphasis on implementing level-set and immersed boundary methods within a high-performance Navier-Stokes solver to address flame propagation within closed vessels. He wrote his MS dissertation on a theoretical investigation of micro-jet diffusion flames using large activation energy asymptotic methods.
Host: Professor Moshe Matalon