|Kingston upon Hull
|From £18,622 annual stipend, per annum (22/23 rate)
|7th December 2023
|7th January 2024
Dr Edward Skevington, Dr Robert Dorrell, Dr Charlie Lloyd, University of Hull
Dr Adam McArthur, University of Leeds
Applications are invited for a funded PhD position at the Energy and Environment Institute at the University of Hull. In this position, you will be an active member of the Hull-based Fluid Dynamics Group, as well as the Leeds based Turbidites Research Group.
The topic of your PhD will be gravity currents. Gravity currents are fluid flows along a horizontal boundary driven by a density difference between two regions of fluid, for example a salt water current spreading underneath a fresh water ambient is a classic experiment (see video). These currents exist in buildings as ventilation flows, in industry as spillages of toxic gas, and examples in the environment include cold fronts, powder snow avalanches, and turbidity currents. The frontal mixing of a gravity current has a strong effect on the dynamics, especially the driving force and resultant current speed, but is not yet understood.
Your PhD will address the following questions: what is the rate of mixing at the front of a gravity current, and how does this effect the propagation speed? These are fundamental questions in fluid dynamics, and answering them will require new insights into the physics at play. The impact of the new understanding will be to inform and enhance models describing industrial and environmental flows, which will enable higher quality prediction, and for hazardous currents will enable more targeted and successful mitigation measures.
The aim of your PhD will be to quantify the process at the front of gravity currents: their speed and the rate of frontal mixing. Your investigation will be principally numerical, with training provided to develop and use advanced employing 3D Large Eddy Simulation (LES) or Direct Numerical Simulation (DNS). In addition, you will engage in simplified mathematical modelling, to give insight on the trends observed. You will establish how the frontal dynamics of the current depend on the steepness of the underlying topography, gravity currents on slopes; how it depends on the viscosity of the current; how it depends on the density of the current, non-Boussinesq effects; and/or the difference between currents driven by composition (e.g. salinity) and a suspended particle load as in the case of avalanches or turbidity currents. Ultimately, a quantitative model of the effects of ambient flow is desired that can be used to predict the effects for a broad class of flows. There will be opportunities for you to develop and extend the project beyond these initial objectives, to study other aspects of gravity currents and stratified turbulence.
You should have a good first degree (at least a 2:1 Honours degree, or international equivalent) in a relevant subject (e.g. Mathematics, Physics, Engineering, Computer Science). A Masters (at Merit or Distinction level) is desirable but not essential. You should be able to demonstrate knowledge of the fundamental principles of fluid dynamics, e.g. the incompressible Navier-Stokes equations, and ideally have some experience in programming and numerical methods.
Apply now, by clicking the 'Apply' button, above
Type / Role: