a approach lower jet noise

1. Reaction EnginesReaction Engines
Satamanyu DashSatamanyu Dash

2. MASTER MINDSMASTER MINDS
Dr. Hans von Ohain
GERMAN
Sir Frank Whittle
UK

3. Newton’s Third LawNewton’s Third Law
““For every action, there is anFor every action, there is an
equal and opposite reaction.”equal and opposite reaction.”

4. How Do Jet Engines Work?How Do Jet Engines Work?
Hot gas in the combustion chamberHot gas in the combustion chamber
exits at a high velocity through theexits at a high velocity through the
exhaust, which is the open end of theexhaust, which is the open end of the
engine, as it pushes with equal forceengine, as it pushes with equal force
against the opposite, or closed, end ofagainst the opposite, or closed, end of
the engine. These engines are alsothe engine. These engines are also
referred to as reaction engines. Thereferred to as reaction engines. The
common example of this principle is aircommon example of this principle is air
escaping from the neck of a balloon.escaping from the neck of a balloon.

5. Processes of a Jet Engine:Processes of a Jet Engine:
Thrust of a jet engine is produced by aThrust of a jet engine is produced by a
four-stage process:four-stage process:
IntakeIntake
CompressionCompression
CombustionCombustion
ExhaustExhaust

6. Diagram of the Four StageDiagram of the Four Stage
ProcessProcess
This simplified illustration shows that a basic turbojet engineThis simplified illustration shows that a basic turbojet engine
is essentially a tube where thrust is produced by a four-stageis essentially a tube where thrust is produced by a four-stage
process. Outside air enters at the intake and is directed to theprocess. Outside air enters at the intake and is directed to the
compressor where it accelerates. Then, the air mixes withcompressor where it accelerates. Then, the air mixes with
fuel in the combustion chamber, ignites, and exits through thefuel in the combustion chamber, ignites, and exits through the
turbine section and the exhaustturbine section and the exhaust..

8. At the front of the engine, theAt the front of the engine, the
turbine shaft drives aturbine shaft drives a
compressorcompressor. The compressor. The compressor
works a lot like the turbine only inworks a lot like the turbine only in
reverse. Its purpose is to drawreverse. Its purpose is to draw
air into the engine and pressurizeair into the engine and pressurize
it.it.

9. Then oxidation of organic fuel occurs. The fuel is ejected into the
combustion chamber which rises the velocity of compressed air
And moves a shaft which is ultimately connected to a turbine.

10. On its way out the nozzle,On its way out the nozzle, somesome of theof the
gas pressure is used to drive agas pressure is used to drive a turbineturbine. .
A turbine is a series of A turbine is a series of rotorsrotors or fansor fans
connected to a single shaft. connected to a single shaft.

11. How the Processes WorkHow the Processes Work
TogetherTogether
The turbine, which is in the path of theThe turbine, which is in the path of the
heated air, acts like a windmill.heated air, acts like a windmill.
It captures much of the energy of theIt captures much of the energy of the
high velocity heated air and transmitshigh velocity heated air and transmits
its spin to the compressor by means ofits spin to the compressor by means of
a connecting shaft.a connecting shaft.

12. Advantages of Jet EnginesAdvantages of Jet Engines
compared to reciprocating enginescompared to reciprocating engines
Fewer working partsFewer working parts
Less maintenanceLess maintenance
Cheaper fuelCheaper fuel
Greater operating speedsGreater operating speeds
AltitudesAltitudes
Climb rates offer increased capabilitiesClimb rates offer increased capabilities
Less warm-up timeLess warm-up time
Torque is practically nonexistentTorque is practically nonexistent
Can fly in any types of weather conditionsCan fly in any types of weather conditions
TOP DISADVANTAGE-TOP DISADVANTAGE-NOISENOISE

13. Compressor and turbine noise results from the
interaction of pressure fields and turbulence
for rotating blades and stationary vanes.
Within the jet engine, the exhaust jet noise is
of such high level that the turbine and
compressor noise is insignificant during most
operating conditions. However, low landing-
approach thrusts cause a drop in exhaust jet
noise and an increase in low pressure
compressor and turbine noise due to greater
internal power handling. The introduction of a
single stage low pressure compressor
significantly reduces the compressor noise
because the overall turbulence and interaction
levels are diminished. Also, the combustion
chamber is another source of noise within the
engine. However, because it is 'buried' within
the engine's core, it does not have a
predominant contribution.

14. Deep corrugations, lobes, or multi-lobes give
the largest reduction in noise level, but
performance penalties limit the depth or
number of corrugations or lobes. The same
overall area as the basic nozzle must be kept,
so when using this method, the final diameter
of the suppressor may have to be increased
causing excessive drag and weight results.
Again, the noise reduction principle is to
minimize the exhaust jet velocity while still
maintaining performance objectives. The
most successful method used is to mix the hot
and cold exhaust streams within the engine
and expel the lower exhaust gases through a
single nozzle

15. THANK YOUTHANK YOU
LETS MAKE A NOISE FREE WORLDLETS MAKE A NOISE FREE WORLD
MAINLY THE PILOT HAS TO FLY AND CONTROL
GEAR SYSTEM IN AN EFFICENT WAY.
INTERNAL WALLS AND INLET WALLS OF
ENGINE SHOULD BE COVERED WITH A HEAT
AND NOISE ABSORBING MATERIAL CALLED
GLASSWOAL.
THE ENGINE SHOULD CHANGED MAXIMUM IN 10
YEARS.