Ballistics Flashcards
(40 cards)
Define ballistics
The scientific study of the motion of projectiles.
What are the 4 types of ballistics
Interior (Internal)
Intermediate
External
Terminal
What is internal ballistics
The scientific study of the operating process within the gun from the moment that the propellant is ignited until the projectile leaves the barrel
What are the objectives (goals) of internal ballistics?
Launch the projectile safely
Consistent performance between shots
Achieve the highest possible muzzle velocity
What is the all burn point?
Where all the propellant has been consumed
What is explosion heat (Qex)?
The amount oh heat liberated in the combustion of 1kg of propellant
Define Pioberts Law
The surface of a burning propellant recedes layer by layer in a direction normal to the surface.
What is intermediate ballistics?
The study of the transition from internal to external ballistics that occurs in the vicinity of the muzzle
What are the 2 parts of bottle shock?
Barrel shock - sides
Mach disc - front
What are the types of flash?
Pre-flash
Primary flash
Muzzle glow
Intermediate flash
Secondary flash
What are the three main ways to minimize muzzle flash?
Muzzle devices ( flash suppressors)
Type of propellant
Propellant additives
What are the 3 main reasons for muzzle devices?
Reduce recoil
Suppress flash
Decrease report
What are the 3 types of silencers?
Blast absorption
Blast dissipation
Blast containment and controlled release
What are the properties of a projectile?
Mass
Calibre
Nose Shape
Spin Rate
What are the properties of the atmosphere
Air Density
Temperature
Pressure
What is trajectory?
The path taken by the C of G of the projectile
What is drag co-efficient? (Cd)
Drag coefficient (C d ) quantifies the drag of an
object through a fluid (Air or Water).
What is yaw?
Angle between axis of projectile and that of the velocity vector or trajectory.
What are the characteristics of propellants ?
Burning Rates
Force Constant
Form Function
Pressure Index
Co Volume
Ballistic Size
Remember 4
What are the six areas of distribution of energy when the gun is fired
Projectile, translational and rotation
Heat in the gas
Gun recoil
Driving band engraving and friction of the bore
Unhurt charge and gases
Heat in the gun
What are the four phases of internal ballistics.
Charge ignition
Combustion prior to projectile motion
Combustion up to the all burnt point
Gas flow and projectile motion after all burnt point to muzzle.
How can the round to round regularity of muzzle velocity be improved
If burning finishes while the shell is still well back in the bore.
Increase pressure
Increase temperature
The muzzle gas flow field during firing consists of what two phases?
The precursor blast field that proceeds the projectile exit from the muzzle
The main blast field that follows as high pressure propellant gases are ejected into the air
What is a bore evacuator?
It prevents propellant fumes from entering crew compartments.
Works by creating pressure diffentials during and after firing
High pressure propellant gases are stored in the evacuator as the round passes through the barrel.as the round exits the muzzle, the high pressure gases flow out the muzzle. This may increase the secondary flash
