A generalised Fully Lagrangian Approach for gas-droplet flows

The proposed project is based on the synthesis of mathematical and engineering approaches to simulate gas-droplet flows. It comprises the development of a new mathematical formalism, which will then be applied to enhance an existing approach to simulate two-phase flows. It will make it possible to perform simulations with higher resolution: more accurate calculations, and more physical phenomena will be captured.
The project will focus on non-trivial generalisation of the mathematical approach to spray modelling developed by Professor Osiptsov, known as the Fully Lagrangian Approach (FLA). In the mathematical modelling community, this method is known as a promising approach to calculate particle/droplet concentrations. However, its current applications are restricted to simplistic flows with dilute mono-sized admixture. In the framework of the project, droplet evaporation, polydispersity of admixture, and the effect of droplets on the carrier phase (two-way coupling) will be taken into account and incorporated in the model. The corresponding mathematical model will be implemented in the Computational Fluid Dynamics (CFD) software OpenFOAM. The developed model will be applied to simulate the evolution of droplet distribution in sprays formed in direct-injection internal combustion (Diesel and gasoline) engines. The results of numerical simulations will be validated against experimental data provided by colleagues in the Advanced Engineering Centre, University of Brighton. OpenFOAM is an open-source and widely used CFD software, which will make the project outcomes accessible to specialists interested in sprays.

The project will have an impact in the following areas:
1. Academics in mathematical modelling (short-, mid- and long-term)
2. CFD development (short-, mid- and long-term)
3. Automotive engineering (mid- and long-term)
4. Academics in research of 'gas-droplet' and 'gas-particle' flows (engineering, pharmacy, biomedical and environmental studies) (long-term)
5. Industry, which relies on 'gas-droplet' and 'gas-particle' flows (engineering, pharmacy, biomedical technology) (long-term)

The new mathematical formalism, which will be developed in the framework of the proposed project, will be of interest to specialists in applied mathematics and mathematical modelling of multiphase fluid flow. It will be a non-trivial generalisation of the Fully Lagrangian Approach to simulate two-phase flows. This impact will be delivered through the Advanced Engineering Centre (AEC) (University of Brighton) networks, presentations at the workshops with industrial partner Ricardo UK Ltd, international conferences and publications in leading international refereed journals.

The implementation of the new model within an open-source CFD software OpenFOAM as a Lagrangian solver will be beneficial for the CFD developers' community. The new solver will be available to this community; it will be demonstrated how the developed methods can be implemented in any other in-house, open-source or commercial CFD packages.

Within the proposed project framework, the developed model will be applied to fuel sprays in direct injection engines. The AEC has a comprehensive database of experimental data. This will be used for validation purposes. Designers of fuel injection systems and the automotive industry in general will benefit from an in-depth understanding of the processes involved, which would allow them to identify scenarios for optimal fuel vapour mixture preparation, and to minimise fuel consumption and emissions. This is aligned with the interest of the project's industrial partner, Ricardo UK Ltd, and will have an impact on future developments in the UK automotive industry. The wider public will also benefit from the impact of more efficient and 'green' combustion engines. The AEC infrastructure will enable the research team to disseminate the results of research effectively through regular AEC-Ricardo meetings programmes, and existing AEC networks. The AEC is a member of the Engine Combustion Network (ECN), the Internal Combustion Engine Thermal Efficiency Spoke within the Advanced Propulsion Centre UK (APC), UK Fluid Network.

Gas-droplet flows are essential not only in internal combustion engines but also in many other industrial (cooling, surface coating and processing, delivery of lubricants), medical (pharmaceutical drug manufacturing by spray drying, inhalers), and environmental applications (atmosphere flows, ocean sprays). In all these applications, it is essential to predict droplet dynamics and concentration with high accuracy, which will be provided by the new version of particle-tracking Lagrangian-based solver of OpenFOAM. The new model could be applied to the above-named applications. The new expertise will also facilitate cross-disciplinary research collaborations. This impact will be delivered through existing AEC (University of Brighton) networks, presentations at workshops, international conferences and publications in leading international refereed journals.