Sultan Qaboos Early-Career Research Fellowship/College Lectureship in Mathematics

Following a generous benefaction from the late Sultan of Oman, the College is able to appoint promising early career researchers to a Research Fellowship/College Lectureship in Mathematics.

The appointment is for a fixed term of four years.

The first holder of the post was Dr Anastasia Kisil, who is now Dame Kathleen Ollerenshaw Fellow in Mathematics at the University of Manchester.

The second Sultan Qaboos Fellow was Dr Jacob Page, who has taken up a permanent lectureship at the University of Edinburgh.

The third Sultan Qaboos Fellow was Dr Daria Frank. She is a Senior Teaching Associate in Computational Mathematics in the Department of Applied Mathematics and Theoretical Physics and continues to hold the Fellowship as Honorary Sultan Qaboos Fellow.

Her focusses on high-Reynolds-number buoyancy-driven and multiphase fluid flows, such as turbulent jets and plumes. These localised turbulent flows are ubiquitous in the environment and exist across a wide range of natural and industrial scales: from hairdryer air flows to smoke emitted by factory chimneys to volcanic ash clouds.

The work undertaken by the current post holder combines small-scale laboratory experiments with a rigorous theoretical as well as numerical modelling of the observed phenomena. It is motivated by pressing societal issues such as the mitigation of consequences of large-scale oil spills in oceans, the reduction of urban energy consumption and the optimisation of building ventilation with the aim of creating a safe and healthy indoor environment.

Daria has extensively studied the effects of the background rotation on the dynamics of turbulent plumes. This problem is relevant for understanding the effects of the Earth’s rotation on the pollutants spread in oceans after large-scale disasters, such as the Deepwater Horizon oil spill. A major result of this research is the discovery and the mathematical characterisation of a novel physical instability that leads to the anticyclonic precession of the plume in a rotating environment. A recent highlight of this work is a detailed description of the changes to the multiphase plume structure caused by the background rotation. The overall aim of this project is to establish a theory, based on experimental and numerical results, that can be used to predict the transport and dispersion from localised contaminant sources in a rotating system.

Understanding and improving the ventilation of indoor spaces have become crucial aspects in the fight against the COVID-19 virus. Here, the research of the current post holder focusses on reducing the spread of airborne contaminants in indoor environments and on enhancing their removal from occupied zones. For example, a recent result of this work shows that the so-called air curtain, a high-velocity planar turbulent air jet, can effectively reduce the transport of contaminants from a dirty to a clean zone which occurs due to wakes of people walking along a corridor. Future research in this direction will further investigate how turbulent air flows can be used to optimise the ventilation of a building, for example, by rapidly flushing out contaminated regions, by changing the distribution pattern of aerosol droplets or by efficiently confining the pollutants.