Thermal Energy Analysis of Projectiles during Ricochetting Using a Thermal Camera

Area of Science:

• Ballistics
• Combustion Science
• Materials Science

Background:

• Assessing ignition and explosion risks from projectile impacts is critical for safety in environments with flammable materials.
• Understanding the thermal energy transfer during projectile-target interactions is key to hazard prediction.

Purpose of the Study:

• To investigate the ignition and explosion hazards posed by small-calibre projectiles impacting various materials.
• To quantify the thermal energy generated during projectile ricochets and its potential to ignite flammable substances.

Main Methods:

• Conducted ricochet tests using small-calibre projectiles (e.g., 7.62x54R B-32) against materials like Armox 600 armour plate and concrete.
• Utilized high-speed and thermal cameras to record impact events and measure temperature distributions.
• Calculated thermal energies from projectile disintegration, ricochets, and subsequent thermal radiation.

Main Results:

• Ricochetting 7.62x54R B-32 projectiles off Armox 600 generated 3400-9500 J, sufficient to ignite propane-butane gas.
• Thermal energy from ricochets on non-metallic components was significantly lower (800-1200 J) due to energy absorption by material crushing.
• Determined ignition temperatures and probabilities for selected gases and vapours based on calculated thermal energies.

Conclusions:

• Projectile ricochets, particularly from armour-piercing rounds on hard targets, present a significant ignition risk to flammable gases.
• The material properties of the target heavily influence the thermal energy released during ricochet, impacting ignition potential.
• This research provides crucial data for developing safety protocols in environments where projectile impacts and flammable substances coexist.