Effect of Vessel Temperature on Blast Loads

Abstract

Current prediction methods for blast overpressure from a bursting pressure vessel are based upon an assumption that the blast curves for various vessel pressures and temperatures are roughly parallel. This assumption is used to extend blast curves to long standoff distances from the blast source. A systematic study of temperature effects on blast parameters from a vessel burst revealed that the blast overpressure curves for various temperatures are not parallel, but intersect each other at various distances. Blast overpressures from higher temperatures are greater than those from lower temperatures at close distances, but become close and even slightly lower than lower temperature bursts at farther distances. As a consequence, the parallel assumption results in under- or over-prediction of blast overpressure from high temperature bursts, depending on standoff distance. A common simplification to blast predictions for bursting pressure vessels is to assume that an explosive charge of comparable energy will produce conservatively high blast loads. The work presented in this paper shows that a high explosive approximation is not always conservative. The high explosive blast curves can under-predict impulse for a vessel burst. Recommendations are provided in the paper for circumstances in which the effect of elevated temperature on blast overpressure needs to be taken into account. Blast curves are presented for selected conditions.Copyright © 2004 by ASME