Cool flames are a feature of the low temperature combustion of a hydrocarbon in air. They occur at much lower temperatures than standard combustion and therefore the chemistry is quite different. There is considerable interest in using cool flame reactors in many engineering systems, such as industrial boilers, diesel reformers and even automotive engines, where the unique conditions and chemistry can be exploited to produce new products, reduce emissions or improve overall efficiency. Furthermore, cool flames occur at the transition between slow, safe reactions and explosions. An understanding of this transition is therefore vital in improving process safety.
An important role in the formation of cool flames is played by heat and mass transport. Previous work has used simple chemical analogues for the combustion reaction. Whilst these can yield some qualitative insight, they cannot be compared directly with experimental measurements. This project will implement a more comprehensive, reduced model of cool flames in the absence and presence of terrestrial gravity to identify regions where explosions and cool flames occur, and then compare these to cases which have fluid flow driven by natural convection. These results can be compared with those taken aboard the NASA microgravity aircraft. Crucially, the time for ignition to occur, which is a vital parameter to know in most applications, will be studied. There is also the opportunity to use simple mathematical techniques to analyse the governing equations and derive characteristic expressions for maximum temperature rise, and the concentrations of various intermediate species.
The student will be trained in the mathematical modelling of reactive flows, which will require the development of a number of techniques. Furthermore, the student will become highly skilled in the use of CFD software such as Fluent. Beyond this, the student will have to opportunity to develop their communication skills through the authoring of manuscripts for high ranking journals and by participating in and presenting at leading international conferences.
The development of skills in CFD modelling will make the student an incredibly marketable asset. In particular, there are a wide range of Health and Safety consultancy firms who would be interested in the specific outcomes of this work, as well as the general skillset developed.
This project will involve significant modelling using tools and facilities that exist at the University of Sheffield. Additional support, to allow for presentation at international conferences will be sourced via ongoing funding applications.
Please see this link for information on how to apply: https://www.sheffield.ac.uk/cbe/postgraduate/phd/how-apply. Please include the name of your proposed supervisor and the title of the PhD project within your application.
Applicants should have a good degree in Chemical Engineering, Mathematics or a related discipline. If English is not your first language then you must have an International English Language Testing System (IELTS) average of 6.5 or above with at least 6.0 in each component, or equivalent. Please see this link for further information: https://www.sheffield.ac.uk/postgraduate/phd/apply/english-language.