JET ENGINE

1.An engine that develops thrust by ejecting a jet, especially a jet of gaseous combustion

products.

2.An engine, generally a gas turbine , that develops thrust from a jet of hot gases produced

by burning fuel in a combustion chamber.

BASIC TYPES OF JET ENGINE

• TURBO JET ENGINE

• RAM JET ENGINE

• PULSE JET ENGINE

A.TURBO JET ENGINE

Developers1. Hans von ohain in Germany.2.frank whittle in UK.

General character tics1.General purpose air breathing jet engine.

CONSISTS FOLLOWING PARTS

• 1. Air inlet• 2. Air compressor• 3. Combustion chamber• 4. Gas turbine• 5. Nozzle

Schematic diagram

WORKING• Air taken in from an opening in the front of the engine is compressed to 3 to 12 times

its original pressure in compressor.• Fuel is added to the air and burned in a combustion chamber to raise the temperature

of the fluid mixture to about 1,100°F to 1,300° F.• The resulting hot air is passed through a turbine(PELTON), which drives the compressor. • If the turbine(INCONELOR NOMONIC) and compressor are efficient, the pressure at the

turbine discharge will be nearly twice the atmospheric pressure, and this excess pressure is sent to the nozzle to produce a high-velocity stream of gas which produces a thrust.

• Substantial increases in thrust can be obtained by employing an afterburner. It is a second combustion chamber positioned after the turbine and before the nozzle.

• The afterburner increases the temperature of the gas ahead of the nozzle.• The result of this increase in temperature is an increase of about 40 percent in thrust at

takeoff and a much larger percentage at high speeds once the plane is in the air.

BURNING PROCESS DIFFER FROM THAT IN A PISTON ENGINE

• In piston engines the burning gas are confined to small volume and as the fuel burns the pressure increase dramatically.

• In turbo jet engine the air and fuel mixture passes unconfined through the combustion chamber. As the mixture burn its temperature increase dramatically but pressure decrease few percentage.

• Less than 25% air is involved in combustion, the rest act as a reservoir to absorb the heating effect of burning fuel.

THRUST AGUMENTATION

• Thrust can be increase by injecting additional fluid, It is then called WET THRUST.

USES• AIR CRAFT• SPACE ROCKET• CHOOPER

NET THRUST

• FN-(M air + Mf) Vj- M air VWhere, M air- Rate of flow of air through nozzle. Mf- Rate of flow of fuel entering the engine. Vj-Speed of the jet(the exhaust plume) and assumed to be less than sonic velocity. V-True air speed of the air craft. (M air + Mf) Vj)-Nozzle gross thrust. M air V Ram drags of the intake.

B.RAM JET

Developer French inventor RENE LORIN In 1913. A ram jet is an athodyd which is an acronym of

aero thermodynamics duct, is the form of air breathing jet engine.

CONSISTS FOLLOWING PARTS

• 1. Air inlet

• 3. Combustion chamber

• 5. Nozzle

Schematic diagram

WORKING

• It intake air from atmosphere through frontal area which is design to intake and compress the air. when the compress air is reach to combustion chamber it burn at high pressure consistently exhaust the high pressurized air blow through nozzle. Ram jet cannot produce thrust at zero air speed, thus they cannot move the aircraft from a stand still.

• Ram jet therefore required assisted takeoff like JATO to accelerate it to the speed when it begin to produce thrust.

• Ramjet work most efficiently at supersonic speed around MACH 3.

• We can use this type of engine up to MACH 6.

USES

• Missiles using ramjets• Bo marc• BrahMos• MBDA Meteor• Bristol Bloodhound• North American SM-64 Navaho• Akash missile• Sea Dart missile• 2K11 Krug • Artillery shell

NOTE

• Ram jet is frequently confused with pulse jet which uses intermittent combustion.

• But in ram jet employs continue combustion process.

C.PULSE JET ENGINE

Invented by Russian inventor and artillery officer N. Teleshov in 1864.

GENERAL CHARACTERTICSThis is the form of air breathing jet engine

CONSISTS FOLLOWING PARTS

• 1. Air inlet

• 2. Valve or valve less

• 3. Combustion chamber

• 4. Nozzle

Schematic diagram

VALVED PULSE JET ENGINE MECHANISM

WORKING• PULSE JET uses Lenoir cycle.

• Lacking an external compressive drive such as Otto cycle piston and bray ton cycle compression turbine.

• It intake air from atmosphere through frontal area which is design to intake and compress the air. when the compress air is reach to combustion chamber through valve or directly and it burn at high pressure consistently exhaust the high pressurized air blow through nozzle.

FUTURE USES

• Pulsejets are used today in target drone aircraft, flying control line model air craft (as well as radio-controlled aircraft), fog generators, and industrial drying and home heating equipment. Because pulsejets are an efficient and simple way to convert fuel into heat, experimenters are using them for new industrial applications such as biomass fuel conversion, boiler and heater systems, and other applications.

• Some experimenters continue to work on improved designs. The engines are difficult to integrate into commercial manned aircraft designs because of noise and vibration, though they excel on the smaller-scale unmanned vehicles.