Simulation of the Effects of an Air Blast Wave - ELSA - Europa

Case opening d pyra d ex,in d ex,end Number of elementsexplosive1 Eulerian 2e-2 0.001 0.001 0.01 33explosive2 Eulerian 1e-2 0.0005 0.0005 0.005 65explosive3 Eulerian 4e-3 0.0005 0.0002 0.002 159explosive4 Eulerian 2e-3 0.0002 0.0001 0.001 318explosive5 Eulerian 2e-3 0.0002 0.0001 0.0005 499explosive6 Eulerian 2e-3 0.0002 0.0001 0.0002 859explosive7 ALE 2e-3 0.0002 0.0001 0.0005 499Table 3: Comparison of different models for the explosiveThe pressures are here analysed in intervals of 1µsec. The procedure to get the values in space(SCOURBE command in EUROPLEXUS) uses the averaged elemental pressure values for thenodal values. This results in a half value of the pressure at the node between an element inside andan element outside of the detonation zone (see Figure 13). The vertical lines in this figurecorrespond to the distances of the elements that are detonated at a certain time step (can be get fromthe listing). The detonation front can be identified by the steep increasing of the pressure.Therefore, it is important to consider the value of the last element of the detonation front and not thevalue of the last node.Figure 13: Distribution of pressures over distance (explosive1)The maximum pressure of the detonation is increasing with the distance from the initial detonationpoint. The Chapman-Jouguet-pressure is the maximum experimental resulted pressure. The25