Investigation of Blast Performance and Solid Residues for Layered Thermobaric Charges

Abstract

The confined explosion of an annular layered charge composed of a phlegmatized RDX (RDXph) core and an external layer consisting of aluminum powder (Al) or a mixture of ammonium perchlorate (AP) and Al was studied. Experiments were carried out in fully and partially closed structures, i.e., in the explosion chamber of 150 dm3 in volume and in the 40 m3 volume bunker with four small holes and a doorway. Two types of aluminum powder were used in the mixtures. Signals of overpressure from two piezoelectric gauges located at the chamber wall were recorded and the influence of aluminum contents and particle size on a quasi‐static pressure (QSP) was studied. Moreover, the solid residues from the chamber were analyzed by using SEM, TG/DTA and XRD techniques to determine their structure and composition. Pressure and light histories recorded in the bunker enable us to determine the blast wave characteristics and time‐duration of light output. The effect of the charge mass and aluminum particle size on blast wave parameters were investigated. For comparison, the test for RDXph and TNT charges were also carried out.

Nanoscopic fuel-rich thermobaric formulations: Chemical composition optimization and sustained secondary combustion shock wave modulation

“…This can be attributed to the secondary combustion of reactive metal fuel with the detonation products or with oxygen from the air [13,18]. This effect could have the potential to raise the temperature of the gaseous products and strengthens the shock wave [1,9]. from simulation modeling and practical measurements were calculated as function of scaled distance Z, and compared to that of reference charge TNT (Fig.…”

“…detonation products as well as oxygen from the air raises the temperature of the gaseous product cloud, and strengthens the shock wave [4,9,10]. Pressure-time (P-t) history of TBX and its difference from classical high explosive are represented in Fig.…”

Investigation of Fireball Temperatures in Confined Thermobaric Explosions

“…This indicates that aluminum from the compositionsr eacts with detonation products and air in the chamber resulting in an additional heat, which increases temperature of theg aseous mixture. This conclusion is confirmed by the analysis of the solid residue recoveredf rom the chamber after detonation of aluminized explosives [14,21].A luminum oxide was the mainc omponent of this residue. However,t he precise determination of the reaction degree of aluminum from Figure 9o nt he basis of the temperature measured in the chamber is not possible due to the changing of the latter in time.…”

“…This means that aluminum takes part in the anaerobic afterburning reactions with the hot detonation products and the AP decomposition products. In this case, aluminum oxide and aluminum nitrate are present in the calculated explosion products as well as in the solid residue from the chamber [14,21].…”

Thermal Environment inside a Tunnel after Thermobaric Explosion

“…Many studies have been conducted on the overpressure field and pressure damage effects [6][7][8][9][10], while research on thermal effects is less because of the inherent view that the damage severity of shock wave is far greater than that of thermal radiation. This view is always correct for traditional high explosives, but not for TBX, since the addition of high energy metal powder makes the reaction time and space scale of TBX higher than those of high explosives.…”