PhD Study : Assessment of hazards of high-pressure hydrogen tank rupture using coupled CFD-FEM modelling

Summary

Hydrogen vehicles are being deployed as a part of the deep decarbonisation strategy nationally and internationally. These vehicles are expected to provide the same or better level of safety compared to fossil fuel vehicles. Use of gaseous hydrogen stored in composite pressure vessels at nominal working pressures 700 bar is the main solution for onboard hydrogen storage for light- and heavy-duty transport applications. Fire resistance rating (FRR) of modern composite tanks is about 4-6 minutes in gasoline fire. This low FRR makes rupture of such tanks a major safety concern in a case of thermally activated pressure relief device (TPRD) failure.  Blast wave and fireball following a high-pressure tank rupture in a fire represent serious pressure and thermal hazards threatening life and property losses.

Analysis of experimental data shows that a car deformation by the blast and its displacement from original location:

(1) expends significant fraction of mechanical energy of compressed hydrogen released instantaneously during tank rupture,

(2) presence of car over the tank intensifies hydrogen combustion and thus affects fireball dynamics due to higher turbulisation and mixing of released hydrogen under the vehicles. Thus, hazards analysis methods developed for the open atmosphere tank rupture, including Computational Fluid Dynamics (CFD) models, are not perfectly applicable to assess hazards of onboard storage in real scenarios.

Accounting for vehicle deformation and displacement is essential to realistically predict pressure and thermal loads on humans and structures. This is typically done by using Finite Element Methods (FEM).

The project aims to develop a coupled CFD-FEM model applicable to analysis of realistic pressure and thermal loads after onboard tank rupture in a fire in a wide range of scenarios for variety of tank volumes, storage pressure, mounting position on a vehicle; vehicle location (open atmosphere, workshop, tunnel, etc.). ANSYS family of Fluid and Structure computational tools will be used as a platform for model development. Experimental data available in the literature and to be obtained in ongoing H2020 (FCH 2 JU) HyTunnel-CS project, coordinated by Ulster University will be used for the model validation. Outcomes of this project will inform regulators, OEMs, health and safety authorities, fire and rescue services about realistic hazards of potential fire accidents with hydrogen vehicles. The research results will feed development of engineering methodology to assess blast wave overpressure and fireball size in the event of catastrophic tank rupture and development of appropriate prevention and mitigation strategies.

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

Funding and eligibility

The University offers the following levels of support:

Vice Chancellors Research Studentship (VCRS)

The following scholarship options are available to applicants worldwide:

• Full Award: (full-time tuition fees + £19,000 (tbc))
• Part Award: (full-time tuition fees + £9,500)
• Fees Only Award: (full-time tuition fees)

These scholarships will cover full-time PhD tuition fees for three years (subject to satisfactory academic performance) and will provide a £900 per annum research training support grant (RTSG) to help support the PhD researcher.

Applicants who already hold a doctoral degree or who have been registered on a programme of research leading to the award of a doctoral degree on a full-time basis for more than one year (or part-time equivalent) are NOT eligible to apply for an award.

Please note: you will automatically be entered into the competition for the Full Award, unless you state otherwise in your application.

Department for the Economy (DFE)

The scholarship will cover tuition fees at the Home rate and a maintenance allowance of £19,000 (tbc) per annum for three years (subject to satisfactory academic performance).

This scholarship also comes with £900 per annum for three years as a research training support grant (RTSG) allocation to help support the PhD researcher.

• Candidates with pre-settled or settled status under the EU Settlement Scheme, who also satisfy a three year residency requirement in the UK prior to the start of the course for which a Studentship is held MAY receive a Studentship covering fees and maintenance.
• Republic of Ireland (ROI) nationals who satisfy three years’ residency in the UK prior to the start of the course MAY receive a Studentship covering fees and maintenance (ROI nationals don’t need to have pre-settled or settled status under the EU Settlement Scheme to qualify).
• Other non-ROI EU applicants are ‘International’ are not eligible for this source of funding.
• Applicants who already hold a doctoral degree or who have been registered on a programme of research leading to the award of a doctoral degree on a full-time basis for more than one year (or part-time equivalent) are NOT eligible to apply for an award.

Due consideration should be given to financing your studies. Further information on cost of living