Sensing Unsteadiness in Buoyant PLUMES (SUBPLUMES)
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Understanding the environmental impacts of wastewater discharges into oceans, dredged material disposal in coastal marine waters and atmospheric emissions from industrial stacks and volcanoes, requires detailed knowledge of how the multiphase (fluid + particulate) behaviour of buoyant jets and plumes is controlled by the source conditions (e.g. momentum and buoyancy fluxes, plume geometry, etc.). Obtaining reliable measurements at source can, however, prove difficult due to their inaccessibility (e.g. discharges from deep ocean outfalls, oil spills from seabed pipeline fractures or eruptions from volcanic vents). As such, well-established theories for buoyant jet and plume behaviour typically assume time-averaged source conditions, thus disconnecting any inherent source unsteadiness from the more accessible measurements of downstream plume behaviour, such as entrainment characteristics, rise and spreading heights, umbrella cloud formation and collapse mechanisms, and particulate fallout and deposition patterns. This project aims to address this disconnect through the development and application of an inverse modelling approach that will utilise new datasets covering a wide range of unsteady discharge environments, with a spectrum of frequencies and magnitudes to mimic relevant source conditions (e.g. ocean outfalls, volcanic vents). It will combine scaled, parametric experiments in existing laboratory facilities that permit a wide range of environmentally-relevant conditions to be tested, and detailed CFD modelling to enhance links between these analogue laboratory data and field-scale volcanic plume data provided by British Geological Survey (BGS). The laboratory tests will be conducted in an existing large-scale recirculating flow facility within the refurbished Environmental Fluid Mechanics laboratory at the University of Dundee, and will utilise sophisticated measurement techniques such as particle image velocimetry (PIV), laser-induced fluorescence (LIF), laser doppler anemometry (LDA) and micro-conductivity profiling to measure detailed velocity and density fields within the evolving plumes. The study will also focus on identifying and optimising the number, location and period of sensor measurements of particle-laden plume dynamics, both at lab and field scales, to ascertain the extent to which the spectrum of unsteady source conditions can be recovered from these downstream plume measurements. The overall goals of the study will be to improve the dynamic links between plume evolution, particulate fall out characteristics and the temporal variability in source conditions, and implement this new knowledge to improve integral plume models, currently utilised in relevant fields (e.g. ocean engineering, volcanology).
Over the past 16 years, Civil Engineering research at Dundee has maintained its ranking as 1st in Scotland and in the top 10 in the UK. A major contributor to this success has been the internationally-recognised research in Environmental Fluid Mechanics with applications in ocean, coastal, offshore and estuarine flows, fluid-structure interactions, sediment transport processes, marine renewable energy, and computational fluid dynamics combining big data and machine learning. The Fluid Mechanics group has a highly successful track record in winning external research grants from national and international funding agencies and industry. It has excellent research and testing facilities, including wave flumes and recirculating flow tanks, as well as the £2M Scottish Marine and Renewables Testing (SMART) Centre, for research at the fluid-structure or fluid-soil interfaces.
The successful candidate will be supervised jointly by Drs Alan Cuthbertson (UoD), Roger Wang (UoD), and Fabio Dioguardi (British Geological Survey, Edinburgh). Some experience in either experimental fluid mechanics, computational fluid dynamics or numerical simulation is highly desirable.
To be eligible for a fully-funded studentship, covering tuition fees and an annual stipend, the candidate must have no restrictions on how long they can stay in the UK and have been ordinarily resident in the UK for at least 3 years prior to the start of the studentship (with some further constraint regarding residence for education, further guidance can be found on the EPSRC website). Applicants from EU countries other than the UK who do not comply with the residency criteria are generally only eligible for a fees-only PhD studentship award.
Applications will be reviewed and shortlisted applicants will be invited to interview. Interviews are expected to be held between 18th – 22nd June 2018.
It is anticipated that the successful candidate will start on or around 01 October 2018.
Interested applicants should send a cover letter and CV to SSE-RPG@dundee.ac.uk.