School of Mechanical Engineering Sciences
The urgent need to decarbonize the transport and power sectors has resulted in a new interest in hydrogen combustion. However, hydrogen could pose new hazards which need to be assessed before adoption as a replacement for hydrocarbons.
In the switch to a hydrogen economy, releases of hydrogen gas into the environment are inevitable. There are a number of known risks associated with hydrogen release, including the formation of hazardous compounds and the risk of explosion. It is therefore important to be able to model the effect of a release of hydrogen into a densely populated city, for example. Because of the importance to urban air quality, dispersion in the urban environment has already been extensively studied. However, this is a very complex problem, owing to the combined influences of the turbulent, stratified boundary layer, the surface heat flux and the geometry of the built environment itself. For these reasons, most of the existing models for predicting urban air quality are empirical (or semi-empirical), and have been calibrated using decades of field measurement, wind tunnel data and numerical simulations. To date, the greatest concern has usually been heavy gases (from accidental releases) or heavy hydrocarbon exhaust products made slightly buoyant by high temperatures. It is not yet known whether these semi-empirical models will be applicable to the release of hydrogen gas, which is extremely buoyant and for which very little dispersion data is available.
This experimental project will make use of the unique EnFlo wind tunnel, which is part of the National Atmospheric and Measurement Observation Facility and one of only about five worldwide which can simulate the turbulence and temperature characteristics of the Earth's atmospheric boundary layer. Measurements will be carried out in a model city, using a tracer gas mix to emulate emissions of different densities. By examining the velocity, pressure and concentration statistics within the boundary layer, the dominant mechanisms of transport within the urban canopy layer will be characterised and compared, thereby assessing the applicability of existing air quality models to a new hydrogen economy.
How to Apply
Open to UK and International students starting in October 2023.
Applications should be submitted via the Aerodynamic and Environmental Flow PhD programme page. In place of a research proposal you should upload a document stating the title of the projects (up to 2) that you wish to apply for and the name(s) of the relevant supervisor. You must upload your full CV and any transcripts of previous academic qualifications. You should enter ’Faculty Funded Competition’ under funding type.
The studentship will provide a stipend at UKRI rates (currently £17,668 for 2022/23) and tuition fees for 3.5 years. An additional bursary of £1700 per annum for the duration of the studentship will be offered to exceptional candidates.