DrJohn Craske

My research helps us understand — and interact responsibly with — the fluid flows all around us, from air moving through buildings to pollutants dispersing in the atmosphere. Turbulence is notoriously hard to predict: it's chaotic, random, complicated and prone to sudden extreme events. My work develops stochastic (probability-based) models that capture this unpredictability, so we can better describe how fluids mix, transport heat and particles, and occasionally behave in extreme or unexpected ways. I am particularly interested in understanding and modelling the effect that small-scale mixing processes have on large-scale transport. To address these challenges, I use theory and techniques from applied mathematics, combined with field data and direct numerical simulation.

Our group works on the following applications:

Building physics We've been developing stochastic models that capture transitions between different ventilation regimes when buildings are subjected to fluctuating wind loads. We use network models and results from graph theory to understand interactions between different parts of a building within an urban environment.

Ocean mixing We're developing probabilistic models that describe the phenomenon known as double-diffusive convection, which occurs because salinity and temperature in the ocean diffuse at different rates.

Plastic transport in marine environments We're modelling the effect of surface water waves on the dispersion of plastics. We study deformable plastics and model the development of biofilm to quantify its effect on motion.

Optimal transport In collaboration with Aeronautics, we're studying optimal heat transfer problems in fluid mechanics as part of the EPSRC project 'UKRI4171: "MOST definitely": Mobilising Optimal Scalar Transport using semidefinite programmes.' Further information about project MOST:def can be found here.

Biogeochemical modelling of lakes, estuaries and coastal waters We have started using the probabilistic approaches described above to model biogeochemical processes. One specific area of application is water quality and the eutrophication of lakes.

If you're interested in a PhD related to the areas above, please email me — I'm always happy to discuss potential projects.