Research On The Regularity Of Thermobaric Explosive Energy Release And The Completeness Of Aluminum Reaction

The thermobaric explosive energy release and the completeness of aluminum reaction were studied by theoretical analysis, experiments in confined space and numerical simulation. The main research contents and results are as follows:The influence of aluminum content on the explosive detonation parameters was studied based on the established models for the calculation of thermobaric explosive detonation parameter. The results show that the detonation velocity and detonation pressure of thermobaric explosive decrease linearly with the increase of aluminum content. The specific volume of explosion decreases with the increase of aluminum content, and decreases faster when the aluminium content was more than 40%. The explosion heat has maximal value when the aluminium content was between 30% and 40%.The influences of factors, such as principal component proportion, aluminum powder content, Al/O molar ratio and the species of oxidants on the of the thermobaric explosive were experimentally studied under the conditions of equal mass and equal volume in a confined space. The pressure histories of shock waves measured with pressure sensors at a distance of 1.5m were analyzed. The results show that the regularities were the same in the condition of equal mass and equal volume. A positive correlation was found between the content of RDX and the shock wave overpressure and impulse when the aluminum contents were fixed as 40%.The overpressure and impulse at the measuring points reached the maximum when the content of aluminum was 30% or the Al/O molar ratio was about 0.6. The shock wave parameters of the formulas with AP were slightly higher than that with KP when the conditions of the formulas were fixed except the oxidant species (AP, KP).Numerical simulation was applied to the comparison of explosion performances about explosions of thermobaric explosive in a confined space and an open space. It was also used to compare the thermobaric explosive with TNT exploded in a confined space. It’s found that composite wave areas were formed after reflecting and overlaying of the shock waves in the confined space compared with explosion in an open space. The pressures in these areas were higher and the damaging ability was stronger. The shock wave parameters of thermobaric explosives were higher compared with TNT in the confined space.The aluminum reaction model was established to study the completeness of aluminum reaction and the heat of after-burning. The results show that the smaller the size of aluminum particles in thermobaric explosive, the shorter the reaction time. The completeness of aluminum reaction and the heat of after-burning increase with the increase of space dimension.The completeness of aluminum reaction in the process of thermobaric explosive explosion in the confined space was analyzed based on reaction product analysis. The results show that nearly all the aluminum added to the experimental formulas took part in the reaction and was changed to α-Al2O3.