A BIOMIMETIC STUDY OF THE EXPLOSIVE DISCHARGE OF THE BOMBARDIER BEETLE

A biomimetic study of the bombardier beetle’s explosive discharge apparatus was undertaken using numerical (CFD) modelling, first, of the beetle’s combustion chamber, and then of a scaled-up combustion chamber with a view to its application to devices such as gas turbine relighters. The new findings about the existence of a pressure release valve at the beetle’s combustion chamber exit yield a clearer understanding of the physics of the beetle’s mass ejection mechanism. The scaled-up chamber (about 1 cm in length) is modelled by considering the chamber to be filled with liquid hexane which then undergoes vapour explosion through a pressure release valve at the exit. The ejection of vaporised fuel at high exit velocities has a number of applications, including gas turbine igniters.