- Type of research degree
- Application deadline
- Friday 17 April 2020
- Project start date
- Thursday 1 October 2020
- Country eligibility
- UK and EU
- Competition funded
- Source of funding
- Research council
- Dr Sven Van Loo and Dr Junfeng Yang
- Additional supervisors
- Prof Derek Bradley, Prof Sam Falle
- School of Mathematics, School of Mechanical Engineering, School of Physics and Astronomy
According to the UK’s Clean Growth Plan, by 2050, hydrogen energy will account for most of the energy budget for British car and home heating. Hydrogen combustion is barely visible and found to be susceptible to detonation typically for concentrations above 18% v/v in atmospheric conditions. A significant challenge is to monitor and mitigate hydrogen explosion hazards, e.g. Fukushima Daiichi nuclear disaster caused by hydrogen explosion. Therefore, hydrogen explosion safety is paramount to the generation, distribution, storage and utilization of hydrogen.
<p>Hydrogen and combustion research in the School of Mechanical Engineering covers the characterisation of large atmospheric explosions and the possible prediction of their nature through laboratory explosions using a fan-stirred explosion vessel, and has established that the combined effects of dilution of the released H2, and the level of generated turbulence, would reduce the burning velocity. Subsequently, hydrogen laminar, and turbulent, burning velocities and levels of turbulence necessary to extinguish flames under different conditions have been established experimentally and theoretically. In addition, turbulence plays an essential role on enhancing flame propagation, and triggering the onset of deflagration to detonation transitions. </p> <p>Advanced laser diagnostics and computational fluid dynamics provide the opportunity to discover a fundamental understanding about the role of turbulence on hydrogen explosions. The state-of-art of laser diagnostics (fast PIV technique) allows measuring the turbulent burning velocity directly and explore the turbulence-flame interactions. In particular, the turbulence field in front of the flame will be studied. Direct Numerical Simulation (DNS) provides the insights on sufficient turbulence level behind blast/shock wave on triggering the onset of DDT. A range of validation on fidelity of CFD models will be conducted via numerical experiments on hydrogen explosion in a fan-stirred combustion vessel. Hydrogen flame speeds under various turbulent intensity will be investigated experimentally and numerically. CFD modelling of large-scale H2 combustion helps develop strategies and opportunities for monitoring and mitigating hydrogen explosion hazards.</p> <h5>Aim</h5> <p>To understand how turbulence behind shock wave generates onset of hydrogen flame deflagration to detonation transitions.</p> <h5>Background</h5> <p>Demand for hydrogen within UK energy sector will continue to rise over the next decades. Hydrogen combustion is found to be susceptible to detonation in atmospheric conditions. Therefore, hydrogen explosion safety becomes of paramount importance for the generation, distribution, storage and utilization of hydrogen. </p> <p>Leeds Combustion group has developed a unique combustion research rig: fan-stirred spherical vessel MK-II with optical assess, with high speed imaging system and the state-of-art of laser diagnostics (fast PIV laser), which allows measuring the turbulent burning velocity directly and explore the turbulence-flame interactions. We have recently started using the Particle Image Velocimetry technique to study flame development in MK-II bomb. Four variable speed fans control the rms (root-mean-square) turbulent velocity of a fuel/air mixture, and hence the turbulent burning velocity. Initially, increasing the rms velocity increases the rate of burning, but if it becomes too high, the burning can be quenched, particularly when operating very lean. PIV technique provides a closer look at turbulence field in the front of the flame, in which turbulent characteristics, e.g. spectra of turbulent energy, intensity and length scales, can be measured directly.</p> <p>An advanced CFD tool, MG code developed within the School of Mathematics at Leeds, has been applied from astrophysical problems to industrial applications, especially to phenomena that involve turbulence and chemical reaction, such as fires, explosions and catalytic reactors. MG code employs an adaptive-mesh refinement method that makes it possible to resolve all turbulence levels (from integral scale to Kolmogorov scale) via Direct Numerical Simulation. It will be used study the detonation and deflagration regimes of hydrogen flames.</p> <p><strong>Project details</strong></p> <p>Through a combination of PIV measurement and DNS modelling, the project aims to prove our fundamental understanding about the role of turbulence on hydrogen explosions.</p> <ul> <li>PIV Measurement on the turbulent flame speeds for hydrogen-air mixture under various strengths.</li> <li>Characterise the turbulent field in front of the hydrogen flame, e.g. spectra of turbulent energy, intensity and length scales, can be measured directly.</li> <li>DNS modelling on hydrogen combustion and resolves the whole range of spatial and temporal scales of the turbulence; Validate the CFD model against the PIV results.</li> <li>CFD and PIV Analysis provides insights on sufficient turbulence level behind blast/shock wave on triggering the onset of DDT</li> <li>CFD modelling of large-scale H2 combustion helps develop strategies and opportunities for monitoring and mitigating hydrogen explosion hazards.</li> </ul>
<p>Formal applications for research degree study should be made online through the <a href="https://eps.leeds.ac.uk/chemical-engineering-research-degrees/doc/apply">University's website</a>. Please state clearly in the research information section that the research degree you wish to be considered for is “Hydrogen Explosion Safety Management” as well as <a href="https://eps.leeds.ac.uk/mechanical-engineering/staff/1325/dr-junfeng-yang">Dr. Junfeng Yang</a> as your proposed supervisor.</p> <p>If English is not your first language, you must provide evidence that you meet the University's minimum English language requirements (below).</p> <p><em>We welcome applications from all suitably-qualified candidates, but UK black and minority ethnic (BME) researchers are currently under-represented in our Postgraduate Research community, and we would therefore particularly encourage applications from UK BME candidates. All scholarships will be awarded on the basis of merit.</em></p>
Applicants to research degree programmes should normally have at least a first class or an upper second class British Bachelors Honours degree (or equivalent) in an appropriate discipline. The criteria for entry for some research degrees may be higher, for example, several faculties, also require a Masters degree. Applicants who are uncertain about the requirements for a particular research degree are advised to contact the School or Graduate School prior to making an application.
The minimum English language entry requirement for research postgraduate research study is an IELTS of 6.0 overall with at least 5.5 in each component (reading, writing, listening and speaking) or equivalent. The test must be dated within two years of the start date of the course in order to be valid.
<p><strong>UK/EU</strong> – Engineering & Physical Sciences Research Council Studentship for 3.5 years. A full standard studentship consists of academic fees (£4,600 in Session 2020/21), together with a maintenance grant paid at standard Research Council rates (£15,285 in Session 2020/21). UK applicants will be eligible for a full award paying tuition fees and maintenance. European Union applicants will be eligible for an award paying tuition fees only, except in exceptional circumstances, or where residency has been established for more than 3 years prior to the start of the course. Funding is awarded on a competitive basis.</p>
<p>For further information regarding the application procedure, please contact Doctoral College Admissions:<br /> e: <a href="mailto:email@example.com">firstname.lastname@example.org</a>, t: +44 (0)113 343 5057.</p> <p>For further information regarding the project, please contact:<br /> Dr Junfeng Yang, e: <a href="mailto:J.Yang@leeds.ac.uk">J.Yang@leeds.ac.uk</a><br /> Dr Sven Van Loo, e: <a href="mailto:S.VanLoo@leeds.ac.uk">S.VanLoo@leeds.ac.uk</a><br /> Professor Sam Falle, e: <a href="mailto:S.A.E.G.Falle@leeds.ac.uk">S.A.E.G.Falle@leeds.ac.uk</a><br /> Professor Derek Bradley, e: <a href="mailto:D.Bradely@leeds.ac.uk">D.Bradely@leeds.ac.uk</a><br /> </p>
<h3 class="heading heading--sm">Linked funding opportunities</h3>
<h3 class="heading heading--sm">Linked research areas</h3>