Formative 2 - Theory of Design LE/HE/PROP/PYRO Flashcards
What are the roles of Illuminating Compositions?
To provide a steady source of light to illuminate targets
To provide coloured signals
To provide fillings suitable for use as tracers in SAA and other direct fire ammunition
What are the 2 categories of propellants?
1- Liquid
2- Solid
What are some ideal properties for propellant?
1- Acceptable High Energy/ Bulk ratio
2- Predictable Burning rate
3- Low flame temperature
4- Being easily and rapidly ignited
5- Low sensitivities to all other possible causes of initiation
6- Cheap easy and rapid to manufacture and blend
7- Long shelf life
9- Minimum tendency to produce flash or smoke
9- Minimum tendency to produce toxic flames
What are the 2 different types of Liquid propellant?
1- Mono Propellant- single component substance, ignited by electric means
2- Bi- Propellant- Fuel and oxidiser, Ignited by own reaction or ignition system
What are the 2 different types of solid propellant?
1- Collodial- Single, double and triple based
2- Composite
What is the main material in propellant?
Nitrocellulose- NC
Define stability table ranges for propellants & Explosives of N Nitrogen in NC Nitrocellulose
- 7- 11.2- Celluliod
- 2- 11.7- Film/ lacquer
- 7- 13.1- Propellant
- 7- 14.3- Detonating explosives
Define propellant?
An explosive which by controlled burning, provided the gas pressure required to give motion to a projectile.
What are the 2 types of signal composition?
1- Those which produce a light of distinctive colour
2- Those which produce coloured smoke
What aids the performance of propellant?
1- Calorimetric Value
2- Density
3- Burning Rate and Pressure
4- Shape and size
What is the definition of a propellant?
An explosive which, by controlled burning provided the gas pressure required to give motion to a projectile or missile.
What is the main ingredient of a Single Base propellant?
Nitrocellulose
What are the advantages of a double base propellant?
- Higher energy rating
- Easily ignited
- Higher flame temp
- Higher burning rate
Name some of the additive used in propellants?
- stabiliser
- plasticiser
- coolants
- surface moderants
- surface lubricants
- flash inhibitors
- de-coppering agents
- anti wear additives
What are the propellant shapes which would produce a constant burn rate?
- Tubular
- Slotted Tubular
- Cogged
- Star Centre
What are 3 types of solid propellants?
1- Single base propellant
2- Double base propellants
3- Triple base propellant
What does single based propellant consist of?
NC- Nitrocellilous- 12.6- 13.4% N
What are single based propellants used for?
- Small arms propellants, including hearvy machine guns
- Secondary charges for mortars
- Igniters
What do double based propellants consist of?
Basically NC gelatinised with NG
- NG content-between 30% and 60%
What is double based propellant used for?
- In cordites
- In the form of ballistite for primary cartiridges in mortars
- For small arms cartridges where high bulk energies are required
What do triple based propellants consist of?
Heterogeneous-
- Picrite- 40-50%
Do composite propellants contain NC?
No- Do not contain NC but are a physical mixture of fuel and oxident, with binders.
What are the 3 burning rates of propellant?
- Degressive bunring
- Neutral Burning
- Progressive bunring
What does degressive burning mean?
Total surface are decreases as the propellant burns
What are 3 degressive propellant shapes?
- Cord
- Flake
- Strip/ Ribbon
What does neutral burning mean?
External surface decreases at same rate that internal surface increases during burning.
What are 3 neutral propellant shapes?
-Tubular
-Cogged
-Star Centre
Example- RKT motor
What does progressive buning mean?
Total surface area increases during burning
What are the 2 progressive shapes?
-Rosette
-Multi- tubular
Example- high velocity ammunition, artillery, tank
What are some propellant shapes?
-Cord, tubular, slotted tubular, multi- tubular, rosette, strip/ribbon, flake, scroll, ball power, drilled tube, slotted groove tube, star centered tube, cruciform, cogged, axial drilled
What is the definition of primary explosives?
Substance, or mixture of substances used to initiate a detonation or a burning reaction
What are the characteristics of primary explosives?
- Stability over long storage periods
- Optimum sensitivity to applies stimulus
- Optimum output of the required kind
- Compatibility with materials
- safe to handle and load
Name 2 explosive initiators?
- Detonators
- Ignitors
What are the primary explosive compounds?
- Lead Azide
- Lead Styphnate
- Lead Dinitro Rescorcinate
- PETN
- Von Herz mixtures
- ASA compound
What are some additives in propellants?
- Stabilisers
- Plasticisers
- Coolants
- Surface moderants
- Surface lubricants
- Flash inhibitors
- De-coppering agents
- Anti-wear additives
3 ways to control the burn rate?
1- Propellant composition
2- Shape of propellant
3- Size of propellant
3 Types of burning rates for propellant?
1- Degressive burning
2- Neutral burning
3- Progressive burning
What are some neutral burning shapes for propellant?
Tubular, cogged, star centre
What is the main ingredient of a single base propellant?
Nirtocellulose
What are the advantages of a double base propellant?
High energy rate
Higher burning rate
Higher flame temp
Easily ignited
What is the definition of propellant?
An explosive which, by controlled burning provides the gas pressure required to give motion to a projectile or missile.
What are the propellant shapes which would produce a constant burn rate?
Tubular, Slotted tubular, cogged, star centre