Jet engine thermodynamics

Study of All Components of Turbojet Engine, Its Working

& Complete Study of Its Thermodynamics

What Is A Jet Engine?

• A jet engine is a reaction enginedischarging a fast moving jet thatgenerates thrust by jet propulsionin accordance with Newton's lawsof motion.

• It is a machine designed for thepurpose of creating large volumesof high velocity exhaust gases.

• This is done in order to producethe thrust needed to overcome theaerodynamic drag of an aeroplane.

History Of A Jet Engine

• First jet engine was built byEgyptian scientists during 100B.C.

• These devices were known asAeolipile.

• Dr. Hans Von Ohain patented agas turbine engine on27th August 1939

• First Turbojet airline began in1952

Introduction

• Jet engine is nothing but a Gas turbine.

• It works under the principle of Newton’s third law

• It states that “For every action there is equal and opposite reaction”.

• Gas turbine operates like toy balloon

Parts of A Jet Engine

1. FAN2. COMPRESSOR3. COMBUSTOR4. TURBINE5. NOZZLE

Jet Engine

How A Jet Engine Works?

• The basic operation of a jet engine is:-

1. Air enters and is compressed in a compressor

2. Fuel is than added and ignited

3. The resulting gas spins a turbine

4. The turbine powers the compressor

5. The gas than exits the engine at the tail pipe

• The way a jet engine operates is similar to the way an automobile engine operates i.e intake, compression, ignition, exhaust

Types Of Jet Engine

• Ramjet

• Turbojet

• Turbofan

• Turboprop

• Turbo shaft

Brayton CycleThe Fundamental Thermodynamic Cycle On Which Gas Turbine Engines Are Based

Is CalledThe Brayton Cycle Or Joule Cycle

Jet fuels• Jet A , Jet A-1 & Jet B are the fuels mostly used in jet engines.

• Jet B is used in very cold climates where the temperature drops upto-600C

• Jet A-1 & Jet A has the following properties:-

1. Flash point = 380C

2. Auto-Ignition Temperature = 2450C

3. Freezing point A-1 = -470C

4. Freezing point A = -400C

Flast point of a volatile material is the lowest temperature at which itcan vapourize to form an ignitable mixture in air

Thanks…..

Jet propulsion

• What is propulsion?

• The word is derived from two Latin words:

pro meaning before or forwards, and

pellere meaning to drive.

• Propulsion means to push forward or drive an object forward.

• A propulsion system is a machine that produces thrust to push an object forward.