When explosives detonate in a confined space, repeated reflections of the initial shockwave on the walls and other obstacles lead to the development of a long-term quasi-static pressure (QSP). Mixing of the detonation products with an oxygen-rich atmosphere results in an additional energy release through ‘afterburn’ reactions, which further increase the pressure inside the space. High pressure loading from explosive detonations in confined spaces can cause severe structural damage and loss of life, as evidenced by recent terrorist attacks in the UK, such as the 7/7 attacks in London in 2005 (56 deaths, 784 injured) and the Manchester Arena bombing in 2017 (23 deaths, 1017 injured).

Basic empirical methods exist for estimating the peak QSP for some explosives in geometrically simple spaces, but research is ongoing to fully understand the mechanisms of energy release from confined explosions [1]. Government agencies tasked with protecting the public from explosive threats require tools that can quickly assess the risk posed by QSP for a range of possible scenarios. Engineers seeking to develop methods to reduce explosives’ effects require an understanding of how the use of mitigating materials around the explosive affects the energy release into the space. This is particularly important in cases with complex geometry or where mitigating measures cannot completely surround the explosive.

This project will use world-leading experimental approaches to identify the complex mechanisms involved in detonating explosives surrounded by mitigating media in a confined enclosure. This will include measuring the QSP loading, tracking how the explosive fireball expands and interacts with its surroundings, and analysis of how thermal management of the explosive’s energy output can control the subsequent shock loading. Experimental work will also be used to validate numerical testing performed using Computational Fluid Dynamics (CFD) software such as APOLLO Blastsimulator. This software has been successfully used to model the propagation and interaction of explosive shockwaves in geometrically complex environments, and this work will seek to model the thermal energy transfer that occurs when the shockwave interacts with a mitigating material in a confined space.

This studentship is in collaboration with Lawrence Livermore National Laboratory, USA. Experimental and numerical work will take place in the University of Sheffield’s blast laboratory with the support of both the UoS supervisory team and LLNL partners.

Interested candidates are strongly encouraged to contact the project supervisors to discuss your interest in and suitability for the project prior to submitting your application.

Please refer to the EPSRC DLA webpage for detailed information about the EPSRC DLA and how to apply. for detailed information about the EPSRC DLA and how to apply.