The slides prepared to aid the engineering students to prepare the project presentation on topic of Rocket Fuels. The solid rocket propulsion system is explained in detail. We acknowledge the various sources from where the presentation has been made and without whom the presentation would not have been possible.

1. ROCKET
FUELS
JJ TECHNICAL SOLUTIONS
(www.mechieprojects.com)

2. What Is Propulsion?
• Initiating or changing the motion of a body
– Translational (linear, moving faster or
slower)
– Rotational (turning about an axis)
• Space propulsion
– Rocket launches
– Controlling satellite motion
– Maneuvering spacecraft
• Jet propulsion
– Using the momentum of ejected mass
(propellant) to create a reaction force,
inducing motion
At one time it was believed that rockets
could not work in a vacuum -- they needed
air to push against!!

3. Space Propulsion System Classifications
Stored Gas Chemical Electric Advanced
• Electrothermal
• Electrostatic
• Electrodynamic
• Nuclear
• Solar thermal
• Laser
• Antimatter
LiquidSolid Hybrid
Pump FedPressure Fed
MonopropellantBipropellant
Space propulsion
systems are classified by
the type of energy
source used.

4. Solid Rocket Motors
• A solid rocket motor is a system that uses solid
propellants to produce thrust
• Advantages
– High thrust
– Simple
– Storability
– High density Isp
• Disadvantages
– Low Isp (compared to liquids)
– Complex throttling
– Difficult to stop and restart
– Safety

5. Solid Rocket Motors
• Solid rocket motors are used for
– Launch vehicles
• High thrust (high F/W ratio)
• High storage density
– Ballistic Missiles
• Propellant storability
• Excellent aging
• Quick response
– storability
– high F/W ratio)

6. 6
SOLID PROPELLANT ROCKETS
• Solid fuel rockets rely on controlled explosion of a mixture of substances
• Nearly a homogeneous material that is burned
• Similar to gunpowder ~ (75% potassium nitrate, 10% carbon, and 15% sulfur)
• Example: STS Solid Rocket Boosters:
– Contain ammonium perchlorate as an oxidizer and aluminum as a fuel
– Rest of mixture devoted to bonding two reactants
– Once a solid rocket is ignited, can not be turned off

7. 7
OVERVIEW: SOLID ROCKET COMPONENTS

8. 8
MINUTEMAN SOLID ROCKET
Minuteman first stage motor
Minuteman missile systems, operated by Air Force Combat Command are long-range,
solid-fuel, three-stage intercontinental ballistic missiles capable of carrying single
or multiple nuclear warheads. The program began in 1958 and is one of Boeing's
longest military contracts.

9. Solid Rocket Motor Components

10. Thermal Insulation
• Design involves:
– Analysis of combustion chamber environment
• Stagnation temperature
• Stagnation pressure
• Propellant gases (material compatibility)
– Selection of insulation material
– Material thickness determination for various
areas of the motor case
– For the cylindrical part of the case, the walls
are only exposed to hot combustion gases at
the end of the burn

11. The Nozzle
• The design of the nozzle follows similar
steps as for other thermodynamic rockets
– Throat area determined by desired stagnation
pressure and thrust level
– Expansion ratio determined by ambient
pressure or pressure range to allow maximum
efficiency
• Major difference for solid propellant
nozzles is the technique used for cooling
– Ablation
– Fiber reinforced material used in and near the
nozzle throat (carbon, graphite, silica,
phenolic)

12. Ablation
• Meteorite
– Re-entry speed of 10 - 20 km/sec
– Extreme heating in the atmosphere
– Ablation and internal energy modes cooled the
meteorite through its fall
• Ablation gas cloud
• Dissociation
• Internal energy deposition
– Stony-Iron Classification
• (95% of all meteorites)

13. Ignition System
• Large solid motors typically use a three-stage
ignition system
– Initiator: Pyrotechnic element that converts electrical
impulse into a chemical reaction (primer)
– Booster charge
– Main charge: A charge (usually a small solid motor) that
ignites the propellant grain. Burns for tenths of a second
with a mass flow about 1/10 of the initial propellant grain
mass flow.

14. Propellant Grain
• Two main categories
– Double Base: A homogeneous propellant
grain, usually nitrocellulose dissolved in
nitroglycerin. Both ingredients are explosive
and act as a combined fuel, oxidizer and
binder
– Composite: A heterogeneous propellant grain
with oxidizer crystals and powdered fuel held
together in a matrix of synthetic rubber binder.
• Less hazardous to manufacture and handle

15. Conventional Composite
• Fuel
– 5-20% Powdered Aluminum
• Oxidizer
– 65-72% Ammonium Perchlorate (NH4ClO4 or AP)
• Binder
– 8-14% Hydroxyl-
Terminated
Polybutadiene (HTPB)

16. Fuels
• Aluminum (Al)
– Molecular Weight: 26.98 kg/kmol
– Density: 2700 kg/m3
– Most commonly used
• Magnesium (Mg)
– Molecular Weight: 24.32 kg/kmol
– Density: 1750 kg/m3
– Clean burning (green)
• Beryllium (Be)
– Molecular Weight: 9.01 kg/kmol
– Density: 2300 kg/m3
– Most energetic, but extremely toxic exhaust products

17. Oxidizers
• Ammonium Perchlorate (AP)
– Most commonly used
– Cl combining with H can form HCl
• Toxic
• Depletion of ozone
• Ammonium Nitrate (AN)
– Next most commonly used
– Less expensive than AP
– Less energetic
– No hazardous exhaust products

18. Binders
• Hydroxyl Terminated Polybutadiene
(HTPB)
– Most commonly used
– Consistency of tire rubber
• Polybutadiene Acrylonitrile
(PBAN)
• Nitrocellulose (PNC)
– Double base agent

19. Additives
• Used to promote
– Curing
– Enhanced burn rate (HMX)
– Bonding
– Reduced radiation through
the grain (darkening)
– Satisfactory aging
– Reduced cracking

20. FOR COMPLETE PRESENTATION, MORE PROJECTS
PRESENTATIONS AND PROJECT REPORTS VISIT
WWW.MECHIEPROJECTS.COM
Email: contactus@mechieprojects.com
THANKYOU

21. This is purely an academic work and has no financial or other
interest.
The results achieved in this should be independently verified.