UK researchers have been investigating how to predict whether a reacting mixture will explode.

Silvana Cardoso and colleagues, at the University of Cambridge, have worked out how to separate the different effects that remove heat from the reaction and hence prevent explosions. These effects are conduction, where the heat flows through material, and convection, where hot material rises away from the reaction site. 'To date', says Cardoso, 'these effects have been analysed in a coupled form. Previously they have been taken into account either in an empirical way, by modifying simpler solutions valid when only heat conduction is present, or in a complex, numerical calculation. Our new treatment allows us to grasp a whole landscape of explosion phenomena which seemed to be unrelated before.'

Cardoso says 'this project aims to develop a more comprehensive theory of explosion, in which the effects of natural convection, as well as those of forced fluid flow, such as by a pump or a stirrer, may be quantified in an explicit manner.'

Vitaly Volpert, a mathematician at the University of Lyon, France, identifies the key contribution of the research: 'The interest of the work is that the authors compare the numerical simulations with experimental results, and consider a spherical geometry, which has not been done before.' 

Volpert identifies two directions this research could take next, 'If we are talking about fire safety, and this is an important issue, I would say a systematic experimental and theoretical investigation of fuel tanks and so on is needed.' From a theoretical point of view, however, he would like to see a systematic investigation of complex nonlinear dynamics, for example the transition of the behaviour of the combusting system to chaos and chaotic heat explosions.

Colin Batchelor