Stable doubly diffusive convectons

Supervisor(s)

Contact Dr Cedric Beaume or Professor Alastair Rucklidge to discuss this project further informally.  

Project description

Doubly diffusive convection is frequently encountered in natural sciences. For example, solar radiations heat the oceans making their surface warmer. In addition, due to evaporation, the density of salt in the oceans (salinity) increases towards the surface. This doubly diffusive configuration where salinity and temperature diffuse in the ocean is called thermohaline convection and gives rise to interesting phenomena. Indeed, the oceans are structured into thermohaline staircases in which the salinity remains mostly constant but jumps at specific depth levels. Thermohaline convection in these staircases is responsible for an instability called salt finger instability whereby the interface between two layers of different salinities becomes unstable and produces vertically elongated structures (fingers) of salty fluid sinking within the purer layer. This instability has been widely studied and was found to play a major role in the mixing of the oceans at low latitude and to strongly interact with large scale oceanic currents.

In this project, we will investigate the properties of spatially localised doubly diffusive convection states named convectons. These states consist in one or few convection rolls surrounded by motionless fluid and persist in spite of the fact that the fluid is homogeneously forced.

Convectons have recently been studied and revealed interesting properties among which:

(i) a large number of such states co-exists in the same physical conditions and
(ii) they are found below the instability threshold.

We will study the role of such states on the global dynamics of the system. To that aim, we will consider different configurations to find stable convectons. These will constitute the first ever computation of stable spatially localised fluid flows in three dimensions. The characterisation of these convectons will provide invaluable information on their role in the typically chaotic dynamics observed in nature and advance the theory of pattern formation.

Entry requirements

Applicants should have, or expect to obtain, a minimum of a UK upper second class honours degree in Mathematics or a related discipline, or equivalent.

If English is not your first language, you must provide evidence that you meet the University’s minimum English Language requirements.

How to apply

Formal applications for research degree study should be made online through the university's website. Please state clearly in the research information section that the PhD you wish to be considered for is 'Stable doubly diffusive convections’ as well as Dr Cedric Beaume as your proposed supervisor.

We welcome scholarship applications from all suitably-qualified candidates, but UK black and minority ethnic (BME) researchers are currently under-represented in our Postgraduate Research community, and we would therefore particularly encourage applications from UK BME candidates. All scholarships will be awarded on the basis of merit.

If you require any further information please contact the Graduate School Office, e: maps.pgr.admissions@leeds.ac.uk.