SEMINAR ON JET ENGINE

PRESENTED BYDEEPAK KUMAR

ROLL NO-1120854SECTION-M7

INTRODUCTION• A jet engine is a reaction engine that discharges a fast moving jet

which generates thrust by jet propulsion in accordance with Newton's laws of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, and pulse jets. jet engine is nothing but a Gas Turbine.

HISTORY OF JET ENGINE• The first jet engine was built by Egyptian scientists during 100 B.C• This device was known as Aeolipile. • Jet propulsion only took off with the invention of the gunpowder-

powered rocket by the Chinese in the 13th century.

Heinkel He 178, the world's first aircraft to fly purely on turbojet power

HOW DOES AN AEROPLANE FLY

PRINCIPLE OF JET ENGINE :• Principle of jet engine is based on Newton’s second and third law of

motion.

• Second law states that the rate of change of momentum in any direction is proportional to the force acting in that direction.

• Third law states that for every action there is an equal and opposite reaction.

WORKING OF JET ENGINE

WORKING OF JET ENGINE• Sucks in air from front with fan

• A compressor raises the pressure of the air

• Then the compressed air is ignited

• Gas expends and comes out nozzle

• Engine/Aircraft thrusts forward

PARTS OF JET ENGINE

• Air intake (Fan)• Compressor • Combustion chamber• Turbine• Nozzle

PARTS OF JET ENGINE

Air intake

Air intake (Fan) compressor

PARTS OF JET ENGINE

Combustion chamber Turbine

BRAYTON CYCLE

Ideal thermodynamic cycle divided into following process:• Isentropic compression process• Isobaric heat addition process• Isentropic expansion process• Isobaric heat rejection process

TYPES OF JET ENGINE• TURBOJET ENGINE

The turbojet is an airbreathing jet engine, usually used in aircraft. It consists of a gas turbine with a propelling nozzle. The gas turbine has an air inlet, a compressor, a combustion chamber, and a turbine (that drives the compressor).

TURBOFAN

The word "turbofan" is combination of "turbine" and "fan": the turbo portion refers to a gas turbine engine which takes mechanical energy from combustion, and the fan, a ducted fan that uses the mechanical energy from the gas turbine to accelerate air rearwards.

TURBOPROP

A turboprop engine is a turbine engine that drives an aircraft propeller. In contrast to a turbojet, the engine's exhaust gases do not contain enough energy to create significant thrust, since almost all of the engine's power is used to drive the propeller.

Harbin Y-12 Twin Engine Turboprop Utility Aircraft

RAMJET

Ramjets cannot produce thrust at zero airspeed; they cannot move an aircraft from a standstill. A ramjet-powered vehicle, therefore, requires an assisted take-off like a rocket assist to accelerate it to a speed where it begins to produce thrust. Ramjets work most efficiently at supersonic speeds around Mach 3

It is a form of airbreathing jet engine that uses the engine's forward motion to compress incoming air without an axial compressor.

TURBOSHAFT

A turboshaft engine is a form of gas turbine which is optimized to produce shaft power rather than jet thrust. They are even more similar to turboprops, with only minor differences, and a single engine is often sold in both forms.

MERITS & DEMERITSMerits of Jet engine over IC engine

Mechanical efficiency of jet engine is high as compared to IC engine.

Speed of jet engine per HP developed is higher than IC engine.

Ignition and lubricating systems are much simpler in jet engine than IC engine.

Demerits Of Jet Engines Over IC engine• Thermal efficiency of Jet engine is low compared to IC engine.

• Difficult to start.

• Turbine blades need a special cooling system due high temperature.

APPLICATION OF JET ENGINE• The industry they’re most prominent in is in the transport industry,

where they are used to propel aircraft, boats, and in some one of creations such as a turbojet powered truck.

• The first use of the jet engine was to power military aircraft. • Normal type of jet engine is used for domestic purpose i.e. Traveling,

carrying goods etc.• As industrial gas turbine for power generation , natural gas , oil pumps

etc.

LATEST AND FASTEST JET ENGINENorth American X-15This aircraft has the current world record for the fastest manned aircraft. Its maximum speed was mach 6.70 (about 7,200 km/h) which it attained on the 3rd of October 1967

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