Journal of Pyrotechnics Archive

David Howard

Abstract: ‘‘Fireplay’’ is a generalist overview of pyrotechnics. It is indebted (and acknowledges its debt) to seminal works such as Brock’s ‘‘History of Pyrotechnics’’ (1949), yet develops an aesthetic – even metaphysical – discussion of the key question for our profession: ‘Why do fireworks move people?’

Keywords: History, aesthetics, gunpowder

Abstract: A model chemical reaction scheme, in which a substance undergoes a two-stage decay process, is developed. It is shown that this reaction scheme follows the Shimizu hypothesis for pyrotechnic strobe combustion; both decay stages are temperature dependent with only the second generating a significant quantity of heat. The model is derived from the combustion reaction between ammonium perchlorate and fine magnesium powder although reaction of other strobe compositions is expected to proceed in a similar manner. It will be shown that the effects of additives, such as potassium dichromate as a frequency modifier, can be investigated without explicitly including them in the model. The model is therefore a first step towards a useful design tool for developing compositions with specific strobe characteristics.

Keywords: thermokinetic model, strobe composition, Shimizu hypothesis, bifurcation theory, two-stage decay

Ref: JPyro, Issue 27, 2008, pp42-49
(J27_42)