satyam seminar ppt

8/11/2019 Satyam Seminar Ppt

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Mahatma Gandhi Missions College of Engineering and Technology

Noise Reduction in IC Engines

Guided by:Mr. Ravindra Ram

SubSat


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Introduction

Harmful Effect Of Noise Various type of noise produce in IC engine Method For Reducing Noise in IC Engine Conclusion Disadvantage

Content


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Sound Sound is a periodic disturbance in the molecule w

generated by vibrating objects. Sound level is measured in decibel.

Noise Noise is conveniently and concisely defined as

sound .

Introduction


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Harmful Effect Of Noise

Noise pollution.Loss of hearing ability. May damage the heart.

Upsets the chemical balance of the body. Increases the cholesterol level in the blood. Dilates the blood vessels of the brain.


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Various type of noise produce in IC engine

Aerodynamic NoiseCombustion Noise Mechanical Noise Exhaust System Noise

Intake System NoiseCooling System Noise


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Aerodynamic Noise Aerodynamic noise includes exhaust gas and intake air noias well as noise generated by cooling fans, auxiliary fans any other air flow.

Combustion NoiseCombustion noise refers to noise generated by the vibrati

surfaces of the engine structure, engine components aengine accessories after excitation by combustion forces.


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Mechanical Noise Mechanical noise refers to noise generated

by the vibrating surfaces of the engine

Components and engine accessories afterExcitation by reciprocating or rotate in enginecomponents.

Exhaust System NoiseExhaust system noise includes the noise from exhaust gas leamuffler and noise emitted from the vibrating surfaces of the system components.The reduction of exhaust system noise include proper selection olengths and diameters and proper positioning of the exhaust outlet.


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Intake System Noise Intake system noise includes noise generated by the flothrough the systems air inlet and noise emitted from the vsurface components.

Cooling System Noise

Water cooled engines are typically cooled by using a radiator exchanger with an axial flow fan is used to draw cooling athe radiator.


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Method For Reducing Noise in IC Engine

Reflective muffler

Reflective mufflers are those mufflers that uses forattenuation sound by changing cross sections inthe internal structure.This mean that sound wave are produce are

cancel themselves out in the muffler.In this reflection occur there is change in thegeometry or an area discontinuity.The important tools are analytic modelling andevaluation of network theory. Refle


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Video of Reflective muffler


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Absorptive Muffler

Absorptive mufflers are uses for soundattenuation by sound absorbing materials. They dissipate the acoustic energy into heatenergy through the use of porous materials asmineral fiber.

The important tools are absorbing materials.This muffler are consist of straight, circularand perforated pipe.


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In this large steel housing.

Between the perforated pipe the casing isa layer of sound absorptive material thatabsorbs some of pressure.In the absorptive muffler create less back

pressure as compare to the reflectivemuffler


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Hybrid Mufflers

The muffler is a metal container with holes, baffles, and chambers that muffles exhaustnoise.

The muffler and exhaust system help tominimize engine noise, reduce pollutants

released into the atmosphere,This type of muffler is the best muffler toreduce the noise. Mufflers that combine the working principleof a reflective muffler and an absorptive

muffler .

Hybr


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Procedure of joint of hybrid mufflers

and silencer

In this muffler joint gasket aregoes inside of the silencer side

pipe.Then muffler side pipe are jointmuffler joint gasket and silencerside pipe.


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Holes in pipe

ResonatingChamber

Inner Pipe

Exhaust GasFlow

Sound Waves

The second chamber repeat with noise same as the absorbing noise thatover.The second chamber is the important function as reflow area.It allow an even flow of gas to the outlet.

This assure the quite release of gas to the atmosphere through the outlet.


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Resonatin

Exhaust GasFlow

Multi-Pass Silencer

In the multi-pass silencer first chamber. The gas enters the

the silencer.Their is hundreds of small jet flows are provide


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Repeats process into the second chamber.The second chamber absorbing the noise that is left over.After this the gases are passing in the third chamberIn this chamber the left over noise are easily reduceAfter this quite gases are released


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Active noise control

ANC is generally achieved throughthe uses of analog circuitIn this noise cancellation speaker may

be located with the sound to beattenuated.

The primary noise converts the sound pressure to an electrical signal.

This signal is then sent to a controllerwhere a new signal is generated.


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This signal activates a control source.An error sensor detects the residual sound after control source.The error microphone which adjusts or modifies the control signal to ocancellation process.

Between this process, the two wave form(180degree) generated and noise


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Reactive Muffler

This is the single cylinder muffler.

In this three perforating pipe are apply.This pipe contain hundred of hole

present when exhaust gas and soundwave are enter.Then sound wave are disturbed by

perforations.When these gases and noise goes to thesecond chamber through perforating

pipe the noise are reduced.


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Dissipative Mufflers

1. Perforated, galvanized steel2. Fibber glass

3. Steel casing4. Low turbulence air passages.


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Conclusion

Improving the engineering in many noisy objects has cut noise n by 30 decibels

Reducing sound at the sources by an average of 10decibelsoundness in half.

By this we can reduce noise in vehicle


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