Hydropower is a major contributor to the world wide resource of renewable energy. Highly aerated flows occur in reservoir spillways and plunge pools and in many hydraulic structures such as ski jumps, stilling basins and hydraulic jumps. These flows are characterised by their fast flow velocities up to 40 m/s, and by the fact that there are significant differences in energy dissipation between model and full scale flows which were attributed to the higher air content at full scale. Recently, the compression and expansion of air bubbles was shown to play a crucial role in the energy dissipation in plunge pools, explaining these scale differences, Müller (2019). The water-air mixtures behave like a compressible medium with some very interesting characteristics- the speed of sound for water with 10% air content e.g. is 33 m/s, much less than the speed of sound in water (1450 m/s) or in air (300 m/s). The exploration of highly aerated water as compressible flow is however only at its very beginning. The questions of the effect of negative (subatmospheric) pressures, potential dynamic effects such as pressure oscillations, the transition form supersonic to subsonic flows etc. have not even been touched. In this project, the effects of air content on the performance of hydraulic structures will be explored using theoretical analysis, numerical modelling and data from published experiments.
Key Skills: Hydraulics / Fluid Mechanics, Matlab
Entry Requirements A very good undergraduate degree (at least a UK 2:1 honours degree, or its international equivalent).
Closing date: applications should be received no later than 31 August 2020 for standard admissions, but later applications may be considered depending on the funds remaining in place.
Funding: full tuition fees for EU/UK students plus for UK students, an enhanced stipend of £15,009 tax-free per annum for up to 3.5 years.
How To Apply
Applications should be made online here selecting “PhD Eng & Env (Full time)” as the programme. Please enter Gerald Muller under the proposed supervisor.