Research Experience

  • 2018 - 2022
    Atmosphere–Ocean Dynamics Group — DAMTP, University of Cambridge
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    Thesis Summary: 

    Climate models are sensitive to the rate of CO2 and heat uptake into the ocean. “Storms” in the upper ocean regulate this interaction with the atmosphere; however, global models fail to accurately capture these processes dominating the turbulent submesoscales (<1km). The developed novel high-performance computational fluid dynamics (CFD) simulations and advanced mathematical data analysis techniques now help climate models represent these unresolved scales. These simulations enabled greater understanding of the role that one such oceanic “storm” — Symmetric Instability — plays on the atmosphere–ocean communication.

     

    Submesoscale Instability and Turbulent Mixing in Frontal Regions of the Upper Ocean
    • Numerically investigated a convective inertial-like instability in strong oceanic fronts responsible for enhanced mixing of heat, CO2, and other biogeochemical tracers.
    • Modelled the interactions between instabilities and turbulence in frontal regions to understand their influence on long-term dynamics, working with Professor John R. Taylor in the Atmosphere–Ocean Dynamics Group.
    • Collaborations across 5 international institutions and between observational, theoretical, & computational scientists comprise the holistic SUNRISE project.

  • 2017 - 2018
    Flow Physics & Aeroacoustics Laboratory — Stanford University
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    Spatio-temporal Stability and Nonlinear Pattern Formation in Stratified Ekman Layers
    • Extended previous work in the spatial and temporal stability of Ekman layers to include the effects of stratification, modelling both oceanic and atmospheric boundary layers [Paper].
    • Modelled the effects of rapid rotation on these stratified shear flows via Linear Kinematic Simulations using a formulation of Rapid Distortion Theory [Report].
    • Explored nonlinear pattern-forming ability permitted by this stratification, motivated by a number of characteristic DNS simulations, working with Professor Sanjiva Lele.
    • Investigated this pattern formation by way of analogy to the secondary instabilities in Rayleigh-Bénard convection [Report].

  • 2016 - 2017
    Flow Physics & Computational Engineering — Stanford University
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    Centre for Turbulence Research

    Interfacial Instabilities and Cavitation in Liquid Jets Irradiated by 14 MeV Neutrons
    • Explored hydrodynamic interfacial instability and cavitation-induced fragmentation of liquid jets irradiated by 14 MeV neutrons with Professors Parviz Moin & Javier Urzay.
    • Investigated the consequences of using a fill-tube in Inertial-Confinement Fusion implosions in collaboration with Los Alamos National Laboratory and the National Ignition Facility at Lawrence Livermore National Laboratory [Paper].
    • Analysed the detrimental effects produced during the relaxation of warm dense matter following isochoric heating.

     

    Incompressible Voronoi Moving-Mesh Code for Native Adaptive Meshing and Inherent Galilean Invariance for Turbulence Simulations
    • Designed and wrote a 2D Incompressible CFD code solving the Navier-Stokes equations on a moving Voronoi mesh as a proof of concept for an efficient and exactly Galilean invariant numerical finite volume scheme [Report].
    • Extended this work into a 3D incompressible Large Eddy Simulation code using the new Regent Task-Oriented Parallel programming language based on Legion.

  • 2015 - 2016
    Cavendish Laboratory — University of Cambridge
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    Astrophysical Fluid Dynamics & Nonlinear Dynamics Group

    • Developed a theoretical framework to describe eccentric astrophysical discs in locally axisymmetric coordinates with Professor Gordon Ogilvie [Project I].
    • Designed a modified Riemann solver to approximate the hydrodynamics equations in a non-orthogonal time-varying, shearing, and rotating generalised coordinate system [Project II].
    • Wrote a well-balanced finite volume code to explore instabilities and the break-down of inertial gravity waves to turbulence in these eccentric discs [Thesis, APS Presentation].
    • Dissected the mechanisms by which large-scale zonal structures are generated and studied their modulation of the saturated turbulence in eccentric discs [Paper].

  • 2015
    Laboratoire de Physique — École Normale Supérieure
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    Hydrodynamics and Turbulence Group

    • Designed numerical experiments developing on the Dedalus Spectral code to study the effect of shape and finite size on the evolution of the Parametric Subharmonic Instability with Professor Thierry Dauxois [Brief].
    • Further analysed the stability of internal gravity wave attractors in the ocean, and by studying the saturation and break-down in nonlinear spectral simulations, could infer the contributions to the ocean energy budget.

  • 2013 - 2014
    Lawrence Livermore National Lab
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    Institute for Scientific Computing

    • Began a collaboration with the Berkeley Astrophysical Fluid Dynamics Group (Chris McKee and Richard Klein) and Berkeley Computational Fluid Dynamics Lab (Philip Marcus) to mesh nascent massive protostellar formation with protoplanetary discs using Radiation-Magnetohydrodynamic Simulations [Explication].
    • Developed on the ORION2 Radiation-Magnetohydrodynamics Adaptive Mesh Refinement (AMR) code using the Pluto and Chombo/BoxLib framework initiated at Lawrence Berkeley National Laboratory.
    • Implemented an accurate cooling function which allowed Baroclinicity and the subsequent Zombie Vortices taking advantage of the Second Order Godunov implementation. This cooling reduced the 5x CPU time penalty for the inclusion of radiative cooling to 1.5x, saving upwards of 3 million CPU-hours.

  • 2011 - 2015
    Computational Fluid Dynamics Laboratory — University of California, Berkeley
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    Meshing Adaptive Mesh and Pseudo-spectral Molecular Core-Collapse Simulations
    • Initialised high-resolution Pseudo-spectral simulations using more realistic final conditions from molecular cloud core collapse AMR simulations completed at LLNL.
    • Searched for traces of Zombie Vortices working off of past discoveries of
      Professor Philip Marcus.  [Press, Paper]
    • Post-processed simulation data from protostellar and protoplanetary simulations to determine a search spectrum to verify the existence of vortex lattices in shearing Baroclinic critical layers.

     

    Replication and Growth of Baroclinic Zombie Vortices
    • Studied the propagation, reflection, and energy deposition of Internal Gravity Waves in a variably stratified domain to explain the locations of the Zombie Vortices near the critical layers found in fully non-linear spectral simulations.
      [Abstract, Explication, Paper]
    • Investigated the subsequent growth of the baroclinic instability in protoplanetary discs utilising a 3D Anelastic Navier-Stokes Spectral Code.
    • Utilised a WKB approximation and Poloidal/Toroidal decompositions to derive a dispersion relation for Poincaré waves with height-varying Brunt–Väisälä frequency in a Coriolis-dominated shearing-sheet domain. [Report]
    • Developed a discrete quasi-autonomous form of the dispersion relation to allow for ray tracing governed by the complex-valued Eikonal ray equations. This necessitated the creation of a new complex-valued ray tracing method.

     

    Efficient Discretisation Methods
    • Independent research on Coriolis-dominated shearing-sheet domains inspired theoretical models for internal and inertial gravity waves in variably stratified fluids using Perturbation and Iterative Induction Methods. [Explication]
    • Determined an efficient and novel numerical method to approximate the dispersion relation of a continuously stratified flow stemming from previous supervised independent study on the subject with Professor Philip Marcus.

  • 2013 - 2015
    Microfluidics Laboratory — University of California, Berkeley
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    Microfluidic Circuitry Optimisation — Summer Research Grant (COINS REU)
    • Developed 3D Finite Element creeping flow simulations of 3D-printed and Optofluidic Lithography micro-scale devices to predict performance of novel resistors, transistors, diodes, capacitors, and microbead concentrators designed with Dr. Ryan Sochol and Professor Liwei Lin. [Explication, Paper]
    • Investigated various Lab-on-a-Chip applications of these microfluidic circuit devices.

     

    Microfluidic Drug Delivery Device Simulations
    • Analysed Microfluidic and Magnetohydrodynamic simulations, developing Finite Element code to optimise the solenoidal and Maxwell Coil hybrid actuator with an iron-seeded diaphragm-fluid system.
    • Designed the support hardware for a biomedical active MEMS fluid drug delivery device.

  • 2012
    The Boeing Company
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    Boeing Research & Development

    • Designed and executed experimental flight tests on the 787-8 Dreamliner aircraft given specific data and certification requirements, working closely with the FAA and flight test pilot Michael Carriker.
    • Ensured the test configuration readiness of experimental components for flights.
    • Confirmed agreement between the analysis/simulations and the flight test data, working to rectify any discrepancy.
    • Developed and analysed simulated icing aerodynamic performance test for the 787-9 GEnx certification program. This involved working closely with Aerodynamicists to determine the expected performance and assign testing limitations while using ice shapes.
    • Planned the intended fuel burn for specific weight and balance requirements given by the test and designed the flight test profiles to ensure each experimental condition is met.
    • Documented flight test summaries, and acted on any follow-up experiments. This included any of vibration and thermal simulations and tests, aeroacoustic tests, and further flight simulations or flight tests.

  • 2011 - 2012
    C3UV Laboratory — University of California, Berkeley
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    Centre for Collaborative Control of Unmanned Vehicles

    • Designed and built a fleet of 60 inch autonomous flying wing aircraft employed for atmospheric data collection.
    • Maintained aircraft during and after aerial missions, optimising the payload and configuration.
    • Optimised airfoil profile and cross-section employing CFD code designed in MATLAB.
    • Developed high-level control software on an Arduino ArduPilot Mega for autonomous mission control from initiation of launch to completion.
    • Designed a mission control program in ROS (Robot Operating System) on Linux.

  • 2010
    Tennis Dynamics Laboratory — University of California, Berkeley
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    • Developed high-speed video analysis for the ballistic experimental results of tennis balls fired at variably weighted racquets.
    • Designed a quantitative and objective system to classify tennis racquets.