Snap-through transitions
Snap-Through transitions occur when an elastic structure remains in an equilibrium configuration that suddenly ceases to exist or becomes unstable. The structure is then forced to "jump" to another equilibrium configuration through a brutal shape transition. This phenomenon is harnessed by different species in nature to generate large amplitude and fast motion. This is the case, for example, with venus flytraps and hummingbirds that harness this mechanism to trap their preys. While these transitions are known to be related to the type of bifurcation the system undergoes, there is no general understanding of the mechanisms that select these bifurcations. In this work, we address this problem by analyzing simple systems where an elastic strip is maintained in a buckled configuration and actuated by translating or rotating its boundaries.
I was involved in this project under the supervision of Eva Kanso as part of my Postdoctoral research project in her lab.
Flame front dynamics
A premixed flame constitutes a self sustained chemical reaction that propagates through a gaseous reactive mixture. Under certain conditions, this reactive fluid dynamic problem can be reduced to an equation describing the dynamics of the reactive front. These simplified models provide a fundamental understanding of the physical mechanisms at play in premixed flame dynamics. However, a very few studies have performed quantitative comparisons between the dynamics described by these front equations and the one observed with experimental flames. One of the major difficulties is the three dimensional aspect of the reactive front that makes it difficult to analyze experimentally. In this work we address these questions by carrying experiments in a Hele-Shaw burner, an apparatus that makes the dynamics quasi bidimensional and allows to access the exact shape of the flame at every instant in time.
I was involved in this project during my PhD thesis at IRPHÉ for which I was supervised by Christophe Almarcha and Bruno Denet
Collaborators : Joël Quinard, Elias Al Sarraf, Emmanuel Villermaux, Pedro Luis Garcia Ybarra, Juliette Piketty-Moine, Muhammad Tayyab, Pierre Boivin.