I’m a postdoctoral research associate at the department of Mechanical & Aerospace Engineering at Princeton University. My research is primarily in computational and theoretical fluid dynamics for wave-dominated fluid flows and hydrodynamic stability. Currently I’m investigating surface waves in ocean science, particularly breaking waves in deep and shallow water, and developing interests in bubble dynamics. Previously I have worked as a postdoctoral scholar at the California Institute of Technology, and I received my B.E. (Mechanical and Aerospace Engineering) from the University of Queensland in 2012, and a Ph.D. in Mechanical Engineering from the same institution in 2015. Prior to my time at Princeton, I worked on interface stability and shock wave dynamics in gas dynamics and magnetohydrodynamics (that is, fluids with high electrical conductivities) on a variety of fundamental problems with application in inertial fusion techniques. A full description of my recent research and current interests can be found in my research statement. A description of some key findings follows below.
My research interests cover diverse topics which are unified by the common underlying physical mechanism of wave motion. Currently I am working in the field of ocean science with respect to the dynamics and statistics of breaking ocean waves. These processes contribute significantly to the energy and mass transfer between the ocean and the atmosphere, constituting a major but poorly understood component of climate dynamics. My particular aim is to determine the physics of air entrainment in the sea, and water entrainment in the air, during a breaking event. This is an essentially three-dimensional, multiscale process which requires significant computational resources to investigate fully. In parallel I am working to quantify energy dissipation in shallow water breaking events. I am also contributing to a related multi-pronged project to investigate bubble breakup processes in turbulence.
Previously, I investigated wave motion in compressible flows, which feature different physical processes. Initially, this included the dynamics of converging flows in magnetohydrodynamics (MHD). Fluids modeled by MHD are just like those in canonical fluid mechanics, such as Navier-Stokes or Euler fluids, except that they are electrically conductive and therefore respond to magnetic fields. This has a dramatic effect on their dynamics. Understanding these dynamics in converging flows, or implosions, helps give us some insight into the structure of flows inspired by those in inertial confinement fusion (ICF) and related problems. I also investigated the Richtmyer-Meshkov instability (RMI), which appears when a shock wave accelerates an interface between two fluids of different densities. The RMI (and the related Rayleigh-Taylor instability) is known to disrupt the flows appearing in ICF, and to suppress it may greatly stabilize such flows. In plane flows, the RMI is known to be stabilized in MHD by an external magnetic field (Samtaney, 2003), but it was unknown whether they would be stabilized in converging flows, and in particular in the magnetic field configurations we are interested in. We found that it is indeed suppressed, although some tradeoffs need to be made with respect to the effect the magnetic field has on the flow symmetry.
During my time at Caltech I did some work more on the theoretical side, particularly in the approximate method called geometrical shock dynamics (GSD), which helps us to model the motion of shock waves without having to account for the complicated effects downstream of the shock. On the one hand, I extended GSD to include MHD fast shocks and wrote a numerical solver to yield some interesting basic results, and then went on to investigate nonlinear stability in the more canonical gas dynamics flows. A major outcome of this research was our finding that a large class of smoothly perturbed shock waves in GSD, including those in imploding contexts, are guaranteed to form sharp facets in their geometry at certain quantified times.
As you can see, my interests comprise a big range of problems, which are all approached with a variety of different methods. At their core, though, they all feature waves, and waves are interesting!