1. Weapon Propulsion and Architecture Naval Weapons Systems

2. Introduction n Every weapon requires some form of propulsion to deliver it to its intended target. n Propulsion systems are based on Newton’s Third Law: To every action there is an equal and opposite reaction.

3. The First Missile n 16 th century n Sweden n Rocket Propelled SPEAR fired from a cannon!!

4. Types of Propulsion n Propulsion Types can be divided into two categories: –1) Energy Source Effect of GravityEffect of Gravity Compression of Liquids/GassesCompression of Liquids/Gasses Chemical ReactionChemical Reaction –2) Method of Launch Gravity - a bombGravity - a bomb Impulse - a projectileImpulse - a projectile Reaction - a missileReaction - a missile

5. Gravity Propulsion Simple: Uses the pull of gravity to get the weapon to the target. Used in: - All free fall and glide bombs - Torpedoes launched from aircraft (until it submerges)

6. Impulse Launching Chemical Reaction

7. Impulse Propulsion n Projectile is ejected from a container by means of an initial impulse. n Explosive Propellant Train: 1) 2) 3) Primer Igniter Igniter Propellant Powder

8. Impulse Propulsion

9. Propellants n Smokeless Powders or Gunpowder's: –All are designed to produce large volumes of gases at a controlled rate. –Rate is based on the maximum pressure that can be withstood by the gun barrel, casing, etc.

10. Burn Rate Controlling Factors - controls the pressure generated by the propellant n Size and shape of the powder grain n Web thickness; amount of propellant between burning surfaces of the grain. n Chemical burn rate constant of the propellant material n Percentage of volatile material present.

11. Burning Rates –The Burn Rate increases as both the pressure and temperature rise. – Classification by variation in burn rate: – Degressive : As it burns, the burning surface area decreases – Neutral: The burning surface area remains constant – Progressive : Burning surface area increases as it burns.

12. Interior Ballistics n Action Inside a Gun. –Ignited propellant creates pressure within the chamber that forces the projectile down the barrel. Gun Barrel Step 3 Step 2 Step 1 Pressure

13. Propulsion Propellent Burning Grains n Degressive burning Grains: n BallPelletSheet –StripCord

14. Propulsion Propellent Burning Grains n Neutral Burning Grains: –Single Perforated –Star Perforated *

15. Propulsion Propellant Burning Grains n Progressive Burning Grains: –Multi-Perforated –Rosette

16. Reaction Launch Compression of Liquids/Gasses

17. Propellants n Compressed Air / Gas: –Used to eject missiles or torpedoes from submarines. –Easily controllable; doesn't harm weapons – Problem: Compressor machinery to maintain a supply of compressed gas.

18. Liquid Fuels n More powerful than solid fuels n High volatility n Can’t be stored for long periods

19. Reaction Propulsion n Create a pressure differential in the medium they operate in, i.e. air or water. n Examples include: –Rockets, Missiles –Cruise Missiles –Turbo-jet, and Ram Jet engines

20. Reaction Propulsion n Development of Thrust in a Rocket Motor: Pressure is Balanced Burning Propellant along the inside of the casing exerts pressure in all directions at once, until a nozzle is fitted a one end. Pressure is Un-Balanced Forward Velocity Thrust

21. Reaction Propulsion

22. Bernoulli’s Theory Convergent Divergent Pressure Increases Velocity Decreases Pressure Decreases Velocity Increases

23. Turbojet LM2500 DC 10

24. Turboprop

25. Ramjet Low-Supersonic Mach 3 to Mach 5 JP-4

26. SR-71 Blackbird

27. Scramjet Hypersonic Mach 5 to Mach 20 Hydrogen

28. Advantages / Disadvantages n Solid Fuel –Simple –Unlimited Speed –Any medium/vacuum –No moving parts –Full thrust at takeoff –No booster –Store fully fueled –Ready to fire!

29. Advantages / Disadvantages n Liquid Fuel –Simple –Practically unlimited speed –Any medium/vacuum –Few moving parts –Full thrust on take-off –Less need for booster than air breather –Staged with liquid/solid rockets

30. Advantages / Disadvantages n Turbojet –Large static thrust –Oxygen from air –Common fuels –Thrust independent of speed

31. Advantages / Disadvantages n Ramjet / Scramjet –Simple –No wearing parts –Oxygen from air –Lightweight –Inexpensive to build and operate –Common fuels –Efficient at high speeds/altitudes –Supersonic –Have to get it up to speed to work

32. Questions?