2Contents History Types of Jet engines Major components Working Advanced Jet planes
3History of Jet Engines• Sir Isaac Newton in the 18th century was the first to theorize thata rearward-channeled explosion could propel a machine forward at a greatrate of speed. This theory was based on his third law of motion.As the hot air blasts backwards through the nozzle the plane moves forward.• Henri Giffard built an airship which was powered by the first aircraft engine,a three-horse power steam engine. It was very heavy, too heavy to fly.• In 1874, Felix de Temple, built a monoplane that flew just a short hopdown a hill with the help of a coal fired steam engine.• Otto Daimler in the late 1800's, invented the first gasoline engine.
4• In 1903, the Wright Brothers flew, "The Flyer", with a 12 horse power gas powered engine. • From 1903, the year of the Wright Brothers first flight,to the late 1930s the gas powered reciprocating internal-combustion enginewith a propeller was the sole means used to propel aircraft.• It was Frank Whittle, a British pilot, who designed the first turbo jet enginein 1930.The first Whittle engine successfully flew in April, 1937.This engine featured a multistage compressor, and a combustion chamber,a single stage turbine and a nozzle.• The first jet airplane to successfully use this type of engine was theGerman Heinkel He 178 invented by Hans Von Ohain.It was the world's first turbojet powered flight.
5The W2/700 engine flew in the Gloster E The W2/700 engine flew in the Gloster E.28/39, the first British aircraft to fly with a turbojet engine, and the Gloster Meteor.
9A jet engine is an engine that discharges a fast moving jet of fluid to generate thrust in accordance with Newton's third law of motion.
10Types Of Jet engines Water Jets Motor Jets Turbo jets Turbo fans RocketsRamjets
11TURBO JET ENGINESWorking principle Jet engines are also called as gas turbines. The engine sucks air in at the front with a fan. A compressor raises the pressure of the air. The compressed air is then sprayed with fuel and an electric spark lights the mixture. The burning gases expand and blast out through the nozzle, at the back of the engine. As the jets of gas shoot backward, the engine and the aircraft are thrust forward.
16AIR INTAKE Fan-The fan is a first component in a turbo fan. The large spinning fan sucks in large quantity ofair. Most of the fan blades are made up of titanium.It then speeds this air up and splits it into twoparts. One part continues through the “core” orcenter of the jet engine, where it is acted upon byother jet engine components.
17The second part “bypasses” the core of the jet engine The second part “bypasses” the core of the jet engine. It goes through a duct which surrounds the core to the back of jet engine where it produces much of force that propels the airplane forward. This cooler air helps to quiet the jet engine as well as adding thrust to the jet engine.
19Compressor - The compressor is the first component in the jet engine core.The compressor is made up of fans with manyblades and attached to a shaft. The compressorsqueezes the air that enters it into progressivelysmaller areas, resulting in an increase in the airpressure. This results in an increase in the energypotential of the air. The squashed air is forced intothe combustion chamber.
21Combustor - In the combustor the air is mixed with fuel and then ignited. There are as many as 20 nozzlesto spray fuel into the air stream. The mixture of air andfuel catches fire. This provides a high temperature,high-energy airflow. The fuel burns with the oxygenin the compressed air, producing hot expanding gases.The inside of the combustor is often made of ceramicmaterials to provide a heat-resistant chamber.The heat can reach 2700°.
22Turbine - The high-energy airflow coming out of the combustor goes into the turbine,causing the turbine blades to rotate. The turbinesare linked by a shaft to turn the blades in thecompressor and to spin the intake fan at the front.This rotation takes some energy from the high-energyflow that is used to drive the fan and the compressor.The gases produced in the combustion chamber movethrough the turbine and spin its blades.
23The turbines of the jet spin around thousands of times The turbines of the jet spin around thousands of times. They are fixed on shafts which have several sets of ball-bearing in between them.
24Nozzle - The nozzle is the exhaust duct of the jet engine. This is the jet engine part which actuallyproduces the thrust for the plane. The energy depletedairflow that passed the turbine, in addition to the colderair that bypassed the engine core, produces a forcewhen exiting the nozzle that acts to propel the engine,and therefore the airplane, forward. The combination ofthe hot air and cold air are expelled and produce anexhaust, which causes a forward thrust.
25The nozzle may be preceded by a mixer, which combines the high temperature air coming from the jetengine core with the lower temperature air that wasbypassed in the fan. The mixer helps to make the jetengine quieter.
26Variable Exhaust Nozzle, on the GE F404-400 low-bypass turbofan installed on a Boeing F-18
28Turbopumps Turbo pumps are centrifugal pumps which are spun by gas turbines and are used to raise the propellantpressure above the pressure in the combustionchamber so that it can be injected and burnt.Turbo pumps are very commonly used with rockets,but ramjets and turbojets also have been known to usethem.
29Afterburners (reheat) Due to temperature limitations with the gas turbines,jet engines do not consume all the oxygen in the air('run stochiometric'). Afterburners burn the remainingoxygen after exiting the turbines, but usually do soinefficiently due to the low pressures existing at thispart of the jet engine; however this gains thrust, whichcan be useful.
30Thrust reversersThrust reversal, also called reverse thrust, is the temporary diversion of an aircraft engine's exhaust or changing of propeller pitch so that the thrust produced is directed forward, rather than aft. This acts against the forward travel of the aircraft, providing deceleration.
33Feul systemApart from providing fuel to the engine, the fuel system is also used to control propeller speeds, compressor airflow and cool lubrication oil. Fuel is usually introduced by an atomized spray, the amount of which is controlled automatically depending on the rate of airflow.
34. It also increases the energy extracted by the turbine which drives the compressor even faster and so there is an increase in air flowing into the engine as well.
35Cooling systemCooling air then passes through complex passages within the turbine blades. After removing heat from the blade material, the air (now fairly hot) is vented, via cooling holes, into the main gas stream.Cover plates are incoperated on blades
36This acts as a centrifugal compressor to pressurize the cooling air before it enters the blade. Another solution is to use an ultra-efficient turbine rim seal to pressurize the area where the cooling air passes across to the rotating disc.