Dr N. Nikiforakis
University of Cambridge
Emergence of Detonation in the Flowfield
Induced by Richtmyer-Meshkov Instability
Abstract:
Combustible mixtures of gases can support two
steady modes of combustion, namely deflagration
and detonation. Under certain conditions a relatively
low speed deflagration can accelerate to form a
supersonic detonation wave, a process referred to
as deflagration to detonation transition (DDT).
Whilst the behaviour of steady deflagrations and
detonations is reasonably well understood, there
are many gaps in our understanding of the nature
of the transition mechanism. The aim of this
research is to investigate the transition process,
i.e. the reasons behind the change of propagation
mechanism from the advection/reaction/diffusion
mode of a deflagration, to the coupled shock/reaction
system of a detonation wave and in particular the
role of interfacial instabilities. To this end, the
effect of the Richtmyer-Meshkov instability arising
from the interaction of a shock wave with a flame
has been. Transition to detonation is shown to take
place in the neighbourhood of localised temperature
perturbations (hot-spots). Finally, the character
of the interim combustion-driven waves arising from
these hot-spots is analysed.
Aspects related to the formulation (multi-fluid
approach) and the numerical solution (numerical
schemes and adaptive mesh refinement) will also
be discussed.
| Datum: | | 26.01.07 |
Zeit: | | 14:15 Uhr |
| Ort: | | FU Berlin, Institut für Mathematik II, Arnimallee 6, 14195 Berlin. |
Raum: | | 032 im Erdgeschoss |
