When explosives detonate in a confined space, repeated reflections and interactions of the resulting shock leads to the formation of a long-term uniform quasi-static pressure (QSP) in the space. For fuel-rich explosives, secondary combustion (or 'afterburn') of the detonation products in an oxygen-rich atmosphere results in a further energy release which increases QSP. This seminar will cover experimental measurements of QSP for fuel-rich plastic explosives, and the development of a fast-running engineering model for QSP prediction.
Experiments in oxygenated and inert atmospheres are used to measure the pressure and temperatures of three RDX- and PETN-based explosives, using pressure transducers and a high-speed infrared thermometer. These experiments show the high repeatability of QSP generated, and the relative contributions of detonation and afterburn to the total pressure for each explosive.
The observed mechanisms are then used to develop a simplified thermochemical model of QSP for plastic explosives, available as an open-source Python script. Simplified detonation and combustion reactions for the explosives and binders are used to calculate the energy change in the confined atmosphere, and hence the QSP. The resulting predictions are within 3% of the experimental values, offering an increase in accuracy over existing empirical methods, and a significant decrease in effort against more sophisticated CFD methods.
The Terrorism Risk Assessment, Modelling and Mitigation Seminar Series (TRAMMSS) is a virtual seminar series focused on technical topics related to terrorism risk assessment, and modelling, including blast modelling and response; IEDs; vehicles as weapons; CBRN; big data for risk assessment, security and screening; and associated mitigation measures.
Speakers
is a Research Fellow in the Blast and Impact Group at the University of Sheffield. His research focuses on developing experimental methods for pressure measurement in extreme blast and impact events, as well as characterising dynamic material behaviour to enhance protective systems for people and infrastructure.
He frequently advises the media and government on high-profile structural collapses caused by blasts or impacts, including the Baltimore Bridge and the Nova Kakhovka Dam. During his PhD, he investigated the behaviour of sandy soils under high pressures and strain rates, and contributed to full-scale testing and modelling of blast loading on soil-filled gabion structures as part of a Bundeswehr-Dstl collaboration on force protection structures.
More recently, he has developed instrumentation to analyse the pressure distributions of explosives in the very near field and the energy release mechanisms in confined explosions. His current EPSRC-funded research aims to develop materials that mitigate the damaging effects of explosives by managing energy output in the early stages of fireball expansion.
Who should attend
This seminar is open to guests from outside Cranfield, who may work in academia, research, or industry. Due to the potentially sensitive nature of this seminar series, guests should be able to show that they are affiliated with an appropriate bona fide organisation.
Cost
The event is free of charge, but participants must register for the TRAMMSS mailing list in advance.How to register
To attend this seminar, you must register for the TRAMMSS mailing list via the .
Further information on the TRAMMSS community can be found on the main website at cranfield.ac.uk/TRAMMSS.
