Conventional Explosives Flashcards
What are the types of explosions?
Mechanical
Nuclear
Chemical
What is a Mechanical Explosion?
An explosion where the pressure inside a container overcomes the strength of the container, causing a rupture. A container is required for a mechanical explosion to occur.
What is a Nuclear Explosion?
A nuclear explosion is caused by either fission (the splitting of the nuclei of atoms) or fusion (the joining together under force of the nuclei of atoms) causing the release of energy, heat, gas and shock.
What is a Chemical Explosion?
The extreme rapid conversion of a solid or a liquid explosive compound into gases having a much greater volume then the substances from which they are generated. A container is not required for a chemical explosion to occur.
What are the three effects of a chemical explosion?
1) Fragmentation
2) Incendiary
3) Blast pressure
What are the three classes of energetic material?
1) Explosives
2) Propellants
3) Pyrotechnics
What are the three types of combustion?
1) Ordinary Combustion
2) Rapid Combustion (explosion)
3) Instantaneous combustion (detonation)
Air contains what supporter of combustion and in what ratio?
oxygen at 21 parts
Detonation can be defined as?
Instantaneous combustion (However even in detonation there must be some interval)
What is the average velocity of a bomb fragment (measured a few feet from detonation)?
2,700 fps (the approximate speed of a bullet fired from a military rifle)
What is the difference between primary and secondary fragmentation?
Primary fragmentation is from the bomb casing, secondary fragmentation is made up of adjacent objects energized by the blast.
Describe the appearance of fragments from a bomb with high explosive filler?
a stretched, torn and thinned configuration due to tremendous heat and pressure produced by the explosion.
Describe the appearance of fragments from a bomb with low explosive filler?
larger fragments lacking a stretched or thinned configuration.
What will grooving (serration or pre-engraving) a bomb achieve?
fragments produced will have a uniform size, shape and weight.
What is shrapnel?
Pre-cut or pre-formed objects (i.e., nails, ball bearings, or fence staples) that are placed either inside the bomb or attached on the outside.
What is the advantage of shrapnel?
Part of the energy released during the explosion is used to propel the shrapnel rather than being expended in fracturing the case body.
What is the incendiary thermal effect known as radiant heat?
The bright flash (fireball) lasting a fraction of a second at the instant of detonation.
What is the incendiary thermal effect known as Direct Flame?
A contact burn that is longer in duration and can last up to several minutes.
What is generally the least damaging of the three primary detonation effects?
Incendiary Thermal Effect
In a high explosive detonation how fast does the conversion from solid charge to gaseous product take?
0.0001 seconds
In a high explosive detonation how fast do the gases rush away from the point of detonation?
13,000 miles per hour
In a high explosive detonation how much pressure is exerted on the surrounding atmosphere?
700 tons per square inch
How much available energy is used to expand the bomb casing?
half with the remainder used to compress the surrounding environment.
What is the shock front?
The compressed layer of air formed at the instant of detonation that is the leading edge of the positive pressure wave (visible in some cases as a white rapidly expanding circle).