Basic Bricks Flashcards
What are the three types of auxiliary power?
Electric
Pneumatic
Hydraulic
What are the three types of fuzes used in GM?
Impact
Variable Time
Prox
What are the three classes of warheads in GM?
HE
Special
Non-operational
Name the seven basic bricks.
Structure Propulsion Guidance Control Auxiliary power Payload Fuzing
What are the two types of Air-independant propellants?
Liquid Fuel
Solid Fuel
Name four types of Directing Devices (WRT guidance systems)
Wire
Radio
Radar
Laser Beam
What does SACLOS stand for?
Semi Automatic Command to Line of Sight
Define missile guidance.
The ability to alter the direction of the flight of a missile after launch and able to do so until it is close to the point of impact
What are the three types of homing guidance?
Active
Semi active
Passive
What are the three components of a guidance system?
Tracking device
Computing device
Directing device
List three advantages to solid propellants.
Ease of handling and storage
Simple design
Immediate response on firing
Storage container for propellant
What main advantage does a Turbojet have over a Ramjet engine?
No boost is required to get the engine to operating speeds
What are the two types of gyroscopes?
Free
Rate
What are two types of sensor used in control systems?
Gyroscopes
Accelerometers
What elements make up the servo mechanism?
Transducer
Control valve
Actuator
What are the categories of Guided Weapons (reference a table in GW design powerpoints)
- Strategic / Tactical
- Anti-Shipping
- Anti Armour
- Air to Air
- Air to Surface
- Surface to Air
What are the forces acting on GW?
- Thrust Loads
- Acceleration Loads
- Aerodynamic Lift
- Drag/Dynamic Pressure
- Aerodynamic Heating
- Transportation Loads
- Vibration & Resonance
Reasons ammunition may fail?
Incorrect initial aim
change in flight path due to wind/ weather
The unpredictable movement of the target
2 Common Terrestrial References?
Terrain Contour Matching
Magnetic
What are the 3x classes of guidance?
Pre-determined
Control-Path
Homing
4 essential elements of Command systems?
Target tracker
Missile tracker
Computer
Command link
What are the parts of a Beam Riding System?
Target tracker
Beam Producer
Computer
Define Isotropic propagatiion?
Effects that are uniform in all directions eg- blast warhead
2 types of blast HE warheads?
internal
eternal
3 types of special warhead?
Chemical
Biological
Nuclear
What do control loops require?
something controllable
error detection
error conversion
controlling device
What is the min number of free gyroscopes required to measure 3x angular rotations?
Two free gyros required because each free gyro can only measure two angles.
What are 2 types of control valves?
Spool, needle
What are the five types of Jet Engines
Pulse Jet Ram Jet Turbo Jet Turbo Fan Ram Rocket
What are the Advantages to Guided Weapons
Increased Hit Probability
Range
Ceiling
Weight of Fire
What are the Disadvantages to Guided Weapons
Cost
Reliability
Response Time
Minimum Range
Flight Time
Support Requirements
What is the definition of a guided weapon
A guided weapon is a weapon system in which the warhead is delivered by an unmanned guided vehicle
Define Propagation
The manner in which the effect of a Warhead is transmitted
Define Attenuation
Reduction in effect of a warhead as the distance from the point of detonation increases
Define Non-Isotropic Propagation
Directional Effect (e.g. HEAT Warhead)
What factors affect Warhead Choice
Role
Target
Accuracy of the Missile
What are the three types of Fragmentation warheads
Shrapnel
Rod
Continuous Rod
What are the two types of Hydraulic Power Systems
One Shot System
Recirculatory System
What are the Seven Design factors for Auxillary Power Systems
Storage Strength Stability Capacity Rapid Activation Fluctuation Weight
What are the 5x factors effecting GW design?
Size and weight (man portable must be lightweight)
Target (determines speed of missile)
Guidance (homing system - components must be in the head)
Control (aerodynamic control surfaces put pressure on the structure)
Warhead (position of the warhead)
What are the two components of the strucutre?
Airframe
Skin
What are the two types of propulsion systems?
Air dependent (jet engines) Air independent (rockets)
What are the functions of the guidance system?
Acts as ‘navigator’
Recognises it’s own position in relation to the target
Computes the ideal flight path
Then generates corrections and passes them to control devices
What are the 3x types of guidance?
Pre-determined
Controlled-path
Homing
WHat are the 4x means of guidance?
Wire
Radio/Radar
Beam Riding
Homing
What is the function of the control device?
Acts as ‘pilot’
Responsible for manoeuvring based on instructions from guidance unit
What is the purpose of the S&A mechanism?
Reduce risk of accidental initiation during storage and transport,
Arms the payload at a safe distance from operator
What is the purpose of the Airframe Strucutre?
Provides strength,
Holds components together during flight
What is the purpose of the Airframe Skin?
Gives aerodynamic shape,
Protects internal parts,
Adds rigidity and stability
What are the design factors for GW auxiliary power systems?
Weight, Storage, Capacity, Rapid Activation, Fluctuation, Strength, Stability
What is electrical auxiliary power used for?
Energise circuits containing valves, transistors, relays, potentiometers,
initiate electrically initiated explosive devices
What are the 5x electrical power sources?
Dry batteries Mercury Cells Thermal batteries Accumulators Generators/alternators
What is pneumatic auxiliary power used for?
Drive gyroscopes, actuators and turbines,
Pressurise hydraulic/liquid feed systems
What is an advantage to pneumatic aux power systems?
Reliability
What is a disadvantage to pneumatic aux power systems?
Large weight and volume - only feasible for short-range weapons,
Must be kept topped-up in storage
What are the Pneumatic power sources?
Ram Air,
Propellant Gases (Solid, Liquid),
Motor Bleed Off
What is a disadvantage of Ram Air as an auxiliary power source?
Scoops and nozzle cause drag.
Ineffective at low speeds or high altitude (insufficient air intake)
What is a disadvantage of motor bleed off as an auxiliary power source?
Motor must burn for entire duration of flight (otherwise components powered by bleed off will lose power)
Increased pressure from high-performance motors may damage casing
What are the two types of hydraulic aux power systems?
one-shot system (fluid is used and discarded into atmosphere)
recirculatory system (fluid is used and discarded into a reservoir for re-use)
When is an external power supply useful, and why?
To avoid using the missile’s internal supply.
Used for warming-up components before launch, or during missile testing, calibration or alignment.
What state is the electrolyte in a thermal battery in prior to launch?
Solid (then it melts)
Why do missile need to travel at high speed?
To overtake and destroy target.
To overcome counter-measures.
To reduce the time the missile is subjected to atmospheric distubances.
What arethe requirements of the propulsion system?
To acceleration the missile from rest.
Provide sustained thrust or adequate momentum for missile to reach its max range.
Provide consistent level of thrust under all conditions.
Not interfere with guidance or control systems.
What are the limitations of Pulse Jets?
Short valve life due to operating frequency.
Requires a boost to reach operational speeds.
Limited to sub-sonic speeds.
Ceiling limited to 25,000m (same as all air-dependent engines)
List the 5x basic components of the RAM Jet
Centre-body. Intake/diffuser. Fuel Injectors. Combustor. Nozzle.
What are the advantages of the RAM Jet?
Extremely efficient when designed for a given speed.
Cheap and simple to manufacture.
What are some limitations to the Turbo Jet?
Costly and complex to manufacture
~60% power goes to turbine drive
Ceiling 25,000m
What are the advantages of rockets? (Air independent engines?)
Can operate outside of the atmosphere (dont need o2)
Don’t require a boost to reach operational speeds.
Cheap and simple to manufacture.
What are the two types of motor?
Booster motor (high thrust, short period) Sustainer motor (low thrust, longer period)
What are the 3x motor configuations?
Tandem,
Integral,
Wrap around.
What are the 3x factors effecting the location of a motor?
CofG depends on position of fixed wings and determines the manoeuvrability.
If control devices are rear of wings, then CofG must not vary as the propellant burns.
If control devices are forward of the wings, then CofG is not as important. Motor can be mounted to the rear.
What are the main components of Solid Propellant engines?
Engine,
Body Material,
Ignition System,
Nozzle
What are the disadvantages of solid propellants?
Gas output cannot be controlled Difficult to cool Specific impulse lower than liquid propellant Relatively heavy Very large
What are the main components of a liquid propellant engine?
Storage tanks for propellant Engine Injector Combustion Chamber, Ignition System, Nozzle
What are the 3x types of cooling which occurs in liquid propellant engine combustion chambers?
Regenerative,
Film,
Sweat
What are the disadvantages of liquid propellants in propulsion units?
Difficult to handle, Slow reaction, Special Storage needs, Toxic, Expensive Less reliable than solid propellants
How are HE warhead fragments produced and controlled?
Size (by weakening/pre-forming metal casing)
Velocity (by weight and type of HE filling)
Pattern (by position of warhead at point of detonation)
Give some examples of non-operational warheads?
Dummy Prac - inert Prac - with break-up Prac - with smoke/flash Telemetry
What are the 3x methods of achieveing PRX fuze initiation?
Radio/Radar
Barometric
Magnetic/acoustic
What is the function of the control system?
the application of corrective action to maintain a desired performance
It’s task is to manoeuvre the missile quickly and efficiently as a result of deviation error signals from the guidance system
What are the two types of control loops?
Open (semi-automatic)
Closed (Automatic)
The ECU processed signals received from what?
Reference,
Guidance system,
Control SUrface feed-back potentiometer
What two components are collectively called the Reference?
Sensor
Pick-off
What is the role of a sensor?
Detects the movement of the airframe and response with proportional movement
What are the two major properties of a gyroscope?
Rigidity (Gyro Inertia) - property to resist forces tending to displace the rotor from it’s plane of rotation
Gyroscopic precession - property which cause rotor to be displaced due to application of torque
How many rate gyroscopes are required for complete stability?
3 rate gyros are required. A rate gyroscope only measures in one plane.
A free gyroscope can measure in two planes.
3x methods for rotor spin-up?
Pneumatic blast
Electric motor
Mechanical energy
With regards to reference sensor pickoff, what are the two types?
Variable Resistance
Variable Reluctance
What are the 2x types of control devices?
Aerodynamic control
Thrust vector control
What are the requirements of a guidance system?
Recognise relative position of the missile and target
Calculate the ideal flight path to the target
Send correction details to control system
4x types of tracking device systems? (Guidance system not the laser beam list)
Television
Radar
Infra-Red
Optical
4x types of directing devices? (Guidance system. Not the TV list)
Radio
Radar
Wire
Laser Beam
What are the 3x phases of guidance? Describe each.
Launch phase - guidance signals must first be clamped to zero. Guidance must gather the missile onto the correct flight path.
Mid-course Phase - primary system of the issile which keeps it on it’s desired path
Terminal phase - missile is finally guided onto the target. Le Bang.
What is the purpose of the directing device?
(don’t say ‘to direct’)
the means by which commands are sent to the missile (By radio, radar, wire, laser beam)
How does SACLOS work?
Operator must keep sight coincident with target
Missile is then guided onto line of sight be sensors in ground equipment
Ground equipment sense deviation from path and sends corrections to missile guidance unit
Missile adjusts trajectory based on commands from guidance unit.
