Scaling laws for contained explosions

Assessment of structural integrity under postulated accident conditions in fast reactors has been based, in the past, on results of scale model tests conducted with chemical explosives. Though emphasis has currently shifted to the development and use of elaborate computational models to determine structural response in the postulated accident, idealised scale model experiments still serve the useful purpose of providing by extrapolation estimates of pressure, impulse and deformation without much expense or loss of time. However, the choice of appropriate scaling laws is important in performing the extrapolation. The results of experiments carried out for the case of a charge of high explosives set off in open waterfilled cylindrical vessels are presented and compared with earlier work by others. Measured shock overpressures at the vessel wall are reported as also impulse values derived by determining the area under the pressure-time traces. Deviations from free-field scaling laws have been observed which are significant for wall pressures and less so for impulse received by the vessel wall.