Simulation of behavioural modification effects on multiphase pipe flows

First principles mathematical modelling, based on the use of direct numerical simulation coupled to Lagrangian particle tracking and interface tracking approaches, will be used to establish the fundamental particulate and carrier fluid properties that define the flow behaviour of slurries being transferred by continuous flow through pipes under a range of conditions. The aim is to provide basic understanding of these flows, and benchmark solutions that can be used to assess the accuracy of design tools that are more robust to wide ranging differences in plant conditions, composition and particle morphology than the current empirical techniques used in industry. In particular, behavioural modification techniques (such as the use of plasticisers, fluid pH and density changes, and responsive/smart fluids), which have been little used in industry, will be explored to establish how particle suspension, deposition and re-suspension behaviour in such flows can be tailored to meet operational requirements. As legacy retrievals and post operational clean out activities gather pace, therefore, opportunities will arise to intervene to improve flow, mixing and separation processes by the use of additives, or chemical or physical changes. The identification of suitable interventions, and the means to apply, control and evaluate their impact on wastes for disposal has the potential to accelerate decommissioning, and reduce secondary waste generation and plant size.

Overall, the work proposed would lead to fundamental insights into the behaviour of particles within a turbulent fluid flow, as well as the particulate and carrier fluid properties that define the flow behaviour of realistic numbers of particles being transferred by continuous flow through pipes under a range of conditions. The former will allow basic understanding of these flows and, in particular, how behavioural modification techniques impact particle-particle interactions, particle agglomeration and break-up, whilst the latter will provide realistic simulations that are able to predict the impact of a range of different plant and process conditions, slurry compositions and particle morphology on the flow behaviour of slurries. They will also provide benchmark solutions that are of value in testing the accuracy of the more pragmatic engineering approaches currently used in industry (which include simpler computational fluid dynamic techniques).