PhD Study : Using coupled CFD-FEM modelling for the safety assessment of hydrogen-powered vehicles

Summary

Hydrogen-power vehicles are being parked in garages, maintenance shops, underground parking, tunnels and other confined spaces. Blast wave and fireball following the high-pressure tank rupture in a fire represent a major hazard threatening life and incurring property losses. Vehicle deformation and displacement after onboard hydrogen storage tank rupture consumes a part of mechanical energy of compressed hydrogen, affects hydrogen combustion and thus the contribution of chemical energy to the blast wave strength.

The fireball dynamics is also affected by the presence of the vehicle. Hazards of under-vehicle tank rupture in the open atmosphere do not apply to confined scenarios, e.g. tunnels where the blast wave propagates with little decay compared to the open space and fireball propagates with large velocity for long distances compared to the open space. Assessment of energy to deform and displace vehicles is essential to develop engineering tools with a realistic prediction of pressure and thermal loads that would not be over-conservative. This energy can be assessed using the Finite Element Method (FEM) modelling and simulations.

The project aims to develop a coupled CFD-FEM model applicable to the analysis of consequences of onboard hydrogen storage tank rupture in a range of conditions – tank volume, pressure, mounting position on a vehicle, vehicle location, etc. Computational tools for fluid flow simulations and structural analysis will be used as a platform for model development. Experimental data available in the literature and from HyTunnel-CS project will be used for the model validation.

This doctoral study includes identification and prioritisation of knowledge gaps and technological bottlenecks; performing theoretical and numerical studies to close identified knowledge gaps; numerical analysis of structural response to thermal and pressure loads; quantitative assessment of pressure and thermal hazards and associated risks; development and validation of innovative engineering solutions and tools for hydrogen safety engineering, etc. ‎The following aspects and phenomena will be considered: contribution of chemical energy of hydrogen combustion into the strength of the blast ‎wave;‎ blast wave and fireball effect on the structural elements of confined spaces; mitigation of the blast wave e.g. by tunnel splits, laybys, etc.; projectiles, including vehicle, and hazard distance assessment; reduction of projectiles hazards based on the tank location, etc.

‎The expected outcomes of the study include: validated contemporary models; a deeper knowledge of the underlying physical phenomena; innovative prevention and mitigation strategies; etc. The successful candidate will work at HySAFER Centre and will focus on CFD-FEM modelling with use of relevant ANSYS software and Northern Ireland High Performance Computing (NI-HPC) Kelvin-2 cluster. The results of this doctoral research will be used in HySAFER’s externally funder projects and will be reported at international conferences. Publication of results in peer-reviewed journals is expected.

Essential criteria

Applicants should hold, or expect to obtain, a First or Upper Second Class Honours Degree in a subject relevant to the proposed area of study.

We may also consider applications from those who hold equivalent qualifications, for example, a Lower Second Class Honours Degree plus a Master’s Degree with Distinction.

In exceptional circumstances, the University may consider a portfolio of evidence from applicants who have appropriate professional experience which is equivalent to the learning outcomes of an Honours degree in lieu of academic qualifications.

• Clearly defined research proposal detailing background, research questions, aims and methodology

Desirable Criteria

If the University receives a large number of applicants for the project, the following desirable criteria may be applied to shortlist applicants for interview.

• Masters at 65%

Funding and eligibility

This project is funded by:

• SusHY

These fully funded scholarships include a tax-free stipend of £16,909 per annum, subject to satisfactory progress over a 4 year period, tuition fees, and a research budget. These awards are open to home/EU and overseas applicants.