  Understanding the dynamics of premixed flames that propagates in confined
systems is important in a wide range of applications. The study of premixed
flames propagating in a closed channel covers a variety of complexities related
to flame ignition, laminar flame development, and strong non-linear interaction
between the flame and the surrounding walls. Accordingly, to study the dynamics
of premixed flames propagating in closed channels, numerical simulations of the
propagation of distorted tulip flames are carried out in this work. More
specifically, a set of fully reactive compressible transport equations are
solved here using the high-order PPM. A 21-step chemical kinetic mechanism is
employed to model the chemical kinetics and the energy release in an
air-hydrogen mixture. Computational mesh independence studies are carried out
in this work by both refining grid elements and employing different levels of
adaptive mesh refinements (AMR). The main results show that the classic tulip
flame behavior evolves into a distorted one. Indeed, two consecutive collapses
on the flame front are observed, which are related to wave pressure and the
presence of reverse flow. It is particularly found that the pressure wave
produced by the interaction of the flame skirt with the side walls reduces the
flame velocity and contributes to the formation of tulip flames. This is
consistent with the reduction in both flame area and pressure gradient at the
flame tip. Furthermore, the collapse of flame cups is associated with the
formation of the vortex near the channel side walls and the increase of
pressure waves.

Fluid Dynamics;Distributed, Parallel, and Cluster Computing