10-04-2017, 09:00 PM
[attachment=2109]
AIR BREATHING PROPULSION
In contrast to a rocket engine which, in addition to the fuel, carries along an oxidizer, an air-breathing propulsion system uses atmospheric air to oxidize the liquid fuel. Air- breathing propulsion systems include the jet engine, the ramjet and the scramjet. The field of air-breathing propulsion involves various disciplines in science and engineering such as fluid dynamics, turbo machinery aerodynamics, thermodynamics, and materials and structures.
Propulsive device
generates the net thrust to overcome inertia and gains speed
Air breathing propulsive device
uses oxygen in air to burn fuel and to generate thrust
limited to dense atmosphere up to a height of about 100 km
only jet propulsion presented in this seminars
Turbojet
Engines with rotating machinery
Used by most civil and military aircrafts operating at subsonic
speeds ( Mach <1 )
General Electric , Pratt & Whitney , Rolls Royce
Ramjet
Engines without rotating machinery
Used for supersonic missiles up to Mach 5
Soviet SA-6 ,British Sea Dart , French Snecma M-88
Scramjet
Engines devoid of rotating machinery
Will be used for hypersonic missiles above Mach 5
Nasa X-43 , British HOTOL , German Sanger
FUELS USED
Gaseous Fuel Ramjet
* eg. hydrogen
Liquid Fuel Ramjet
* kerosene , synthetic hydrocarbon fuel
eg. US made RJ1, RJ4 ; French CSD07T , CSD15T
Solid Fuel Ramjet
* polymers loaded with metal particles like Mg ,Al or B
eg. Polyether , polyester , polyurethane
ADVANTAGES
Able to attain high speeds up to mach 5
No moving parts so less wear & tear and minimum losses
Reduced weight and smaller engine
Lighter and simpler than turbojet
Higher temperatures can be employed
DISADVANTAGES
Bad performance at lower speeds
Needs booster to accelerate it to a speed where ramjet begins to
produce thrust
Higher fuel consumption
Maximum operating altitude is limited
High temperature material required
THE PROMISED FUTURE
Reusable Launch Vehicle will replace the space shuttle
Space tourism a big industry
Hypersonic passenger airliner
Airplane which can take a passenger to anywhere on globe
within 2 hours
Space flight made cheaper and more common
It could take the present cost of launching a space shuttle from
$ 10 000 a pound to $ 100 a pound
High speed fighter jets
Long range Hypersonic missiles will come into origin