Accidental gas explosions represent an ever-present hazard for process industries handling flammable gases and liquids. There is also an increasing danger of vandals and terrorists using improvised explosive devices in industrial areas neighbouring highly populated residential areas. The consecutive pressure wave generation and propagation can result in unacceptable risk exposition of citizens and infrastructures.
Overpressure histories including the positive peak overpressure, the arrival time and the positive phase duration depend on several parameters such as explosion type (fast deflagration, detonation), and the location and volume of the source term. Therefore, it is necessary to define design rules of protective barriers mitigating the effect of blast wave.
This study is dedicated to the definition of a simplified CFD (Computational Fluids Dynamics) approach to model blast propagation in presence of obstacles (buildings, wall, etc.) in a far field.
For a rapid, precise and efficient evaluation of the protection barrier effect, we need an accurate computational model representing pressure wave propagation and its interaction with obstacles. However, this computational model must be validated first before its application for protection systems design definition.
The objective of the study is to compare the results of this simplified modelling approach using CFD softwares FLACS [Ref 1] and EUROPLEXUS [Ref 2] to one-dimensional analytical solution [Ref 3] and to large scale experimental data. Experimental data are issued from a recent experimental campaign on blast waves interacting with a wall. The blast was generated by large explosions (7m3) of stoichiometric hydrogen-oxygen mixtures diluted by nitrogen. These tests were carried out in INERIS, France. Conclusions are drawn on the applications of the proposed approach to industrial cases.
References
[1]FLACS v10.0 User’s Manual, GexCon, 2013.
[2]EUROPLEXUS User’s Manual, online version: http://europlexus.jrc.ec.europa.eu.
[3]Sedov L.I. Similarity and Dimensional Methods in Mechanics. Academic Press, 1959.
