Dr. Duncan Dockar
RAEng Research Fellow
PhD
Email
d.dockarobfuscate@ed.ac.uk
ORCID
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Biography

I am a Royal Academy of Engineering Research Fellow, investigating the application of nanobubbles for enhanced water and waste-water treatment. I specialise in Molecular Dynamics (MD), Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD) modelling of nanoscale multi-phase fluids, and for my fellowship, I will be developing novel computational tools for simulating nanobubble diffusive stability, growth, collapse, and transport.

During my PhD, I modelled a typical cavitation event of a surface nanobubble, a type of spherical cap-shaped bubble which are pinned to solid surfaces, and considered to be the nucleation sites for this phenomenon. I determined the threshold pressure required to induce their unstable growth, their natural frequency and oscillation dynamics, and finally the high-speed jets that develop during their collapse that can cause surface pitting. In each case, I demonstrated that surface nanobubbles behaved differently to spherical (bulk) nanobubbles, due to their spherical cap shape and pinned contact line, and provided alternative models to predict their cavitation dynamics.

In my post-doctoral roles, I worked in collaboration with Dr Kokou Dadzie and Prof Raffaella Ocone at Heriot-Watt University, modelling dilute granular flows using modified hydrodynamic equations for fine particle control, and investigating how non-equilibrium and non-ideal gas behaviour, can result in anomalous interpretations of nanoscale thermal oscillations.

I have also led the construction of a portable table-top demonstration to visualise high-speed jetting during cavitation bubble collapse, normally too rapid and small to witness with the naked-eye, using submerged balloons and a high-speed camera, which I present at science festivals and open-days.

Papers

Volume diffusion modelling of a sheared granular gas
Thermal Oscillations of Nanobubbles
Shock-induced collapse of surface nanobubbles
Forced oscillation dynamics of surface nanobubbles
Mechanical Stability of Surface Nanobubbles