Two phase flow in the dynamic Earth: Implications for melt flux and chemical differentiation

In the lower parts of the Earth's crust, a mixture of crystalline solid and molten rock may exist simultaneously. This system will develop flow instabilities in response to different forcings, specifically to density contrasts or tectonic forcing. Three fundamental situations can be envisaged: melt is either "squeezed out", "fluxed through" or "accumulated in" interstitial pores between crystals, the parameter space that these situations "occupy" will differ with different forcings, force combinations and melt-rock ratios.
The student will focus on addressing the pure fluid-mechanical phenomena relating to understanding the flux of the viscous phase from deep to shallow, which drives rapid melt transport and chemical differentiation within Earth. The student will aim to establish the characteristics and governing parameters of melt transport at different forcing scenarios both in theory and in different geologically relevant situations. To reach this aim, the student will apply first-principles fluid-mechanical modelling of two-phase flow under different forcings and explore these thoroughly over a dimensionless parameter space. In particular, the student will perform a comprehensive study of the effects of differential flow through a heterogeneous porous media driven by gravity and/or tectonic forcing. Potential generalizations of the theory include the implications of melt flux predictions through the Earths' crust for chemical effects.

The CDT will address the continued need of the UK for highly trained graduates in Fluid Dynamics and deliver impact through the novel research conducted by CDT students. The impact and benefits will reach multiple stakeholders.

Impacts on Skills and People:

Key beneficiaries of the CDT will be the alumni of our current and future programme and the organisations who employ them. Through the technical and professional development training, and the CDT environment, our graduates will have expertise in fundamental theory, analytical and numerical approaches, experimental techniques and application, and in-depth technical knowledge in their PhD area. Moreover they will have leadership, communication, responsible innovation and team working skills, combined with experience of working with academic and industry partners in a diverse and cross-disciplinary environment. This breadth and depth sets our CDT graduates apart from their peers, and positions them to become future leaders in industry, society and academia across a range of sectors. They will obtain the underpinning skills, and long term support through our Alumni Association, to drive future innovation across multiple sectors and act as life-long ambassadors for Fluid Dynamics.

The impact on people and skills will also include staff in our partner organisations in industry and non-profit sectors. Through participation in CDT activities, benefits will include new professional contacts and collaborations and knowledge of cutting edge methods and techniques. Through the CDT and the wider activities of Leeds Institute for Fluid Dynamics (LIFD) we will enhance the skills base in Fluid Dynamics and be the "go to" place to support high level training in end-user organisations.

Impact on Industry and the Economy:

In addition to the availability of trained graduates with excellent technical, professional and personal skills, impacts will arise from the direct innovation in research projects within the CDT. Research outcomes will influence processes, technologies, tools, guidelines and methodologies for our industry partners and other related organisations, leading to economic benefits such as new products, services and spin out companies. For example our current CDT has already led to 2 new patents (BAE Systems), student delivery of consultancy (Akzo Nobel), a flood demonstrator unit (JBA Trust) and a new method for hydraulic analysis (Hydrotec). Partners will also gain an enhanced reputation through being involved in successful and novel project outcomes. Skilled graduates and technology enhancement are key to economic growth, and our CDT will contribute to challenge areas such as energy, transport, the environment, the health sector, as well as those with chronic skills shortage such as the nuclear industry. Many of our partners are non-profit organisations, particularly in the environment and health sectors (e.g. NHS, PHE, Met Office). Impacts here derive through skilled graduates with the training and awareness to apply their expertise in organisations that deal with complex problems of societal importance, and novel research at the interface of disciplines. The cross-disciplinary nature of the CDT particularly supports this.

Impact on Society:

Beyond those who partner directly, many of the research projects have potential to lead to innovations with direct societal benefits (e.g. new techniques for detecting or controlling disease, new innovations in controlling flood risk or pollution, new insights into forecasting extreme weather). Beneficiaries here include professional bodies and government agencies who set policy, define guidance or influence the direction of innovation and research in the UK. The benefits to society will also stem from enhanced public awareness of Fluid Dynamics, both benefiting general public knowledge of science and inspiring the next generation (from all sectors of society) to undertake STEM careers.