Current Research Focus:
In our study we employ the well-vetted, dual-chamber, constant-pressure apparatus to conduct spark-ignited, expanding spherical flame experiments in enclosed environments of low or elevated pressure to study the evolution of such instabilities. While by increasing pressure and flame temperature we can induce hydrodynamic instability because of reduced flame thickness, we can simultaneously change the mixture composition to manipulate the mixture Le to control the diffusional thermal instability. By scaling analysis, we proposed a unifying mechanism of laminar flame propagation with hydrodynamic instability.
Turbulent Flame Propagation:
The other aspect of research aims to understand the role of molecular diffusion on turbulent flames. On contrary to common belief that the role of molecular diffusion (and Lewis number) diminishes at high turbulent Reynolds number, our studies show strong Le effects on flame propagation even at ReT~10k.
The impact process may not always result in immediate merging of the drop and the liquid surface. In fact, under favorable condition the drop can bounce from the impacted surface. The bouncing to merging transition not only depends on liquid properties and impact speed, but thickness of the impacted liquid pool also plays a critical role. We investigate this (non-monotonic) transitions behavior and the underlying physics through experiments and simulations. Apart from analyzing the global behavior of the drop and the liquid pool during the impact process, we also measure the micron-scale interfacial gas-layer profiles trapped between the drop and the liquid surface during the impact process.