Self-aeration and complex flow on hydraulic structures (e.g. stepped spillways)

The design of hydraulic infrastructure and in particular reservoir spillways is an area of significant importance from a safety and economic perspective (consider recent failure incidents at Toddbook, UK 2019 and Oroville, US 2017). There is a large and costly programme of work to upgrade existing infrastructure to ensure resilience in the face of changing climate and increasing extreme weather events.  

Physical models have been used for many years as the prime approach to predict flow behaviour at full-scale, however there is current huge appetite to make use CFD free-surface models. These models have the potential to become an important tool in the design of hydraulic structures, but there a number of critical areas where the current computational models need further development:  

-Ability to reliably capture the self-aeration process and associated air entrainment within the flow (white-water). This has significant impact on predicative capability for water depths, wall pressures and the associated likelihood of highly damaging cavitation; 

-Uncertainty around appropriate and efficient ways to consider the highly turbulent behaviour, such that there is the ability to predict key parameters (depths, velocities, wave profiles) within necessary tolerances.  

-How best to combine predictions from physical and computational models. 

This PhD will use multiphase modelling and new highly detail experimental datasets to provide improved understanding of the self-aeration process with the aim of enabling it to be explicitly captured and accounted for in future CFD models.