Variable air blast fireball of HMX/Al with tailored gradient structures

Abstract

Air blast fireball of the composite explosive is an important way to destroy the target and effectively determines the damage effect. Herein, based on the effect of aluminum powder content on the explosion reaction kinetics of HMX-based aluminized explosives, the cylindrical charges with positive gradient structure (PGS) and negative gradient structure (NGS) were designed and prepared to control the structure and size of air blast fireball. The PGS cylinders exhibited lateral shuttle-shaped flame/fireball and the width of the fireball was 3.901 m, which was increased by about 14% compared with homogeneous cylinders. The NGS cylinders led to the vertical shuttle-shaped flame/fireball that the height of the air blast fireball reached 4.049 m, and had longer durations of the fireball. The numerical fitting results show that the lateral shuttle-shaped flame/fireball and vertical shuttle-shaped flame/fireball gradually changed into spherical-like flame/fireball with an increase from 0 to 30 wt% of outer and inner layer HMX content, respectively. The vertical shuttle flame/fireball gradually changed into a spherical-like flame/fireball with the increase of HMX content. This is a feasible way to regulate the shape and size of the air blast fireball through gradient adjusting the distribution of HMX and Al, which could provide an effective strategy to improve the damage effect.

Keywords

• Thermal damage
• Composite explosive
• Gradient structure
• Air blast fireball