Blast effect from a pancake shaped fuel drop—air cloud detonation (theory and experiment)

A re-analysis of the atmospheric and ionospheric effects of the Flixborough explosion

“…Theoretical and experimental determinations of fuel-air cloud detonations have been carried out by Fishburn (1976), Sichel andFoster (1979), andFishburn et al (1981). In this latter work it was demonstrated that despite having a heat of combustion about 10 times that of the heat of explosion of TNT the detonation of a hydrocarbon-air cloud can yield a ground blast e ect comparable to 20 times its fuel weight in TNT.…”

“…In the work of Fishburn et al (1981) it was noted that peak overpressures, at levels of ∼1:8 MPa, i.e., the detonation pressure for most hydrocarbons, are sustained out to the edge of the cloud with developed impulses of 8000 kPa ms to 20 ms. However, detonations of unconÿned fuel-air clouds may require signiÿcant ignition energy (Fishburn et al, 1981;CCPS, 1994).…”

“…Fishburn et al (1981) have shown that an estimate of the overpressure inside the cloud may be made using a hemispheric form for the explosion. Following the procedure of Warshaw and Dubois (1981), the acoustic wavefront from the surface explosion was represented as an expanding hemisphere and it was assumed that the acoustic energy in the hemisphere for the ground explosion was twice that of a sphere corresponding to the same explosion in free space.…”

“…However, detonations of unconÿned fuel-air clouds may require signiÿcant ignition energy (Fishburn et al, 1981;CCPS, 1994). Thus some "precursor" or trigger for the Flixborough detonation may have been necessary.…”

Influences of the Cloud Shape of Fuel-Air Mixtures on the Overpressure Field

“…The cloud shapes effectively affect the damage scope of the explosion near the ground [15]. Consequently, in the study, we carried out an experiment in the open field, measured cloud shape data with a high-speed color photography system, and recorded the overpressure values with a pressure measurement system.…”