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I am Ahamath Jalaludeen
I am here because I love to give presentations.
You can find me at ahamathjalaludeen@gmail.com
AIR AUGMENTED ROCKETS
Rocket
 A rocket (Italian rocchetta‚ "little fuse") is a missile, spacecraft, aircraft or
other vehicle that obtains thrust from a rocket engine.
 Rocket engines work by action and reaction.
 Rocket engines push rockets forward by expelling their exhaust in the
opposite direction at high speed.
CHEMICAL ROCKETS
 Solid rocket boosters (SRB), or solid rocket motors (SRM), are used to provide thrust in
spacecraft launches from the launchpad up to burnout of the SRBs.
 Compared to liquid-fuel rockets, the solid-fuel are advantageous for the purpose of boosting
launches because they provide greater thrust and do not have the refrigeration and insulation
requirements of liquid-fueled rockets.
 Solid boosters are usually cheaper to design, test, and produce compared to equivalent thrust liquid
boosters.
 It is difficult to stop a solid rocket motor before normal burnout.
 The NASA Space Shuttle used two Space Shuttle SRBs, which were the largest of their type in
production service. The propellant for each solid rocket motor on the Space Shuttle weighed
approximately 500 000 kg
CHEMICAL ROCKETS
 A liquid rocket booster (LRB) is similar to a solid
rocket booster (SRB) attached to the side of a rocket
to give it extra lift at takeoff.
 A liquid rocket booster has fuel and oxidizer in liquid
form, as opposed to a solid-fuel rocket or hybrid
rocket.
 Like solid boosters, liquid boosters can considerably
increase the total payload to orbit.
 Unlike solid boosters, LRBs can be throttled down and
are also capable of being shut down safely in an
emergency, providing additional escape options for
human spaceflight.
Launch of Ariane 44LP two solid rocket booster (smaller) and two liquid
rocket boosters (larger, with no visible plumes)
Solid
rockets
Air-Augmented
rocket
 Air-augmented rockets use air collected during
flight to use as additional working mass, leading to
greater effective thrust for any given amount of
fuel.
 They represent a hybrid class of rocket/jet
engines, similar to a ramjet, but able to also
operate outside the atmosphere.
Normal Chemical Rocket Engine process
Combustion
An
oxidizer
and a fuel
se
↑
in
pressure
Nozzle
Thrust
From
Atmosphere
Concept of Air
Augmented
Rocket
Air
Fuel
An oxidizer
and a fuel
Same
process
 Conventional rocket engine is mounted in the center of a long tube,
open at the front.
 As the rocket moves through the atmosphere the air enters the front of
the tube, where it is compressed via the ram effect.
 As it travels down the tube it is mixed with the hot exhaust from the
engine, which expands the air just as it would in a jet engine,
specifically, a ramjet.
In this way a fairly small rocket can be used to
accelerate a much larger working mass than normal,
leading to significantly higher thrust within the
atmosphere.
Advantages
 The effectiveness of this simple method can be dramatic.
 Typical solid rockets have a specific impulse of about 260 seconds
(2.5 kN·s/kg), but using the same fuel in an air-augmented design
can improve this to over 500 seconds (4.9 kN·s/kg), a figure even
the best hydrogen/oxygen engines can't match.
 This design can even be slightly more efficient than a ramjet as the
exhaust from the rocket engine compresses the air more than a
ramjet normally would; this raises the combustion efficiency as a
longer, more efficient nozzle can be employed.
 Another advantage is that the rocket works even at zero forward
speed, whereas a ramjet requires forward motion to feed air into the
engine.
Disadvantages
 It might be envisaged that such an increase in performance would
be widely deployed, but various issues frequently preclude this.
 The intakes of high-speed engines are difficult to design, and they
can't simply be located anywhere on the airframe whilst getting
reasonable performance – in general the entire airframe needs to
be built around the intake design.
 Another problem is that the air eventually runs out, so the amount
of additional thrust is limited by how fast the rocket climbs.
 Finally, the air ducting weighs about 5× to 10× more than an
equivalent rocket that gives the same thrust. This slows the vehicle
quite a bit towards the end of the burn.
Thanks!
Any questions?
You can find me at ahamathjalaludeen@gmail.com