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MR.Vinod ajnabi

FROM

KRISHNA ENGG

COLLEGE

GAZIABAD(U.P)

KRISHNA ENGG

COLLEGE

GAZIABAD(U.P)

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OUT LINE

INTRODUCTION

THERMAL

STRENGTHVIBRATION

ADVANTAGE

LIMITATION

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CONTINUE

I.C ENGINE

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THERMAL

THERMAL CYCLE

MECHANICAL EFFECIENCY

STROKE OF ENGINE

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THERMAL CYCLE

OTTO CYCLE

DESIEL CYCLE

ATKINSON CYCLEJOULE OR BRAYTON CYCLE

CARNOT CYCLE

STRILING CYCLE

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OTTO CYCLE

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CONTINUE

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DESIEL CYCLE

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ATKINSON CYCLE

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JOULE OR BRAYTON

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CONTINUE

BRAYTON CYCLE ENGINE

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CARNOT CYCLE CYCLE

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STRILING CYCLE

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CONTINUE

SECTION VIEW OF

SRILING ENGINE

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CONTINUE

STRLING ENGINE

MODEL

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MECHANICAL EFFECIENCY

Mechanical efficiency n:

n = (Pb / Pig) = 1-(Pf / Pig)

Where Pb is the brake power, Pig is grossindicated power, and Pf the friction power.

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STROKE OF ENGINE

TWO STROKE (DESIEL,PETROL)

FOUR STROKE (DESIEL,PETROL)

SIX STROKE

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TWO STROKE ENGINE

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FOUR STROKE ENGINE

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BASED ON STRENTH

CYLINDER OF ENGINE

CARK SHAFT

PISTON

CONNECTTING RODWRUST PIN

PISTON RING

FLYWHEEL

ROCKER ARM MECHANISMAND OTHER MECHANICAL DEVICE LIKE,GEAR,PINOIN,GEAR BOX,CLUCTH,ETC

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STRENGTH OF CYLINDER

Automobile-engine cylinders generally cast of

close-grained gray iron approximating the

following composition.

Silicon 1.9 to 2.2%Sulphur not over 0.12%

Phosphorus not over 0.15%

Manganese 0.6 to 0.9%Combined carbon 0.35 to 0.55%

Total carbon 3.2 to 3.4%

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STRENGTH OF CRANK SHAFT

The shaft is subjected tovarious forces but generallyneeds to be analysed in twopositions. Firstly, failure mayoccur at the position ofmaximum bending; this may be

at the centre of the crank or ateither end. In such a conditionthe failure is due to bendingand the pressure in thecylinder is maximal. Second,the crank may fail due totwisting, so the conrod needsto be checked for shear at theposition of maximal twisting.The pressure at this position isthe maximal pressure, but onlya fraction of maximal pressure.

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STRENGTH OF PISTON

Cast Iron piston

Steel piston

Aluminium piston,

http://modelenginenews.org/techniques/materials1.htmlhttp://modelenginenews.org/techniques/materials1.htmlhttp://modelenginenews.org/techniques/materials1.htmlhttp://modelenginenews.org/techniques/materials1.htmlhttp://modelenginenews.org/techniques/materials1.htmlhttp://modelenginenews.org/techniques/materials1.htmlhttp://modelenginenews.org/techniques/materials1.htmlhttp://modelenginenews.org/techniques/materials1.htmlhttp://modelenginenews.org/techniques/materials1.html

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STRENGTH OF CONNECTING

ROD

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STRENGTH OF PISTON RING

Cast iron

Cast iron alloyed forpiston rings

Nodular cast iron alloyedfor piston rings

Bronze

Aluminum Bronze

Phosphor Bronze

Steel

Stainless Steels for use inhigh temperatures

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STRENGTH OF FLYWHEELHigh energy materials

Flywheel from stationary engine. Note thecastellated rim which was used to rotate theengine to the correct starting position by meansof a lever.

For a given flywheel design, it can be derived

from the above equations that the kineticenergy is proportional to the ratio of the hoopstress to the material density and to the mass.

could be called the specific tensile strength.The flywheel material with the highest specifictensile strength will yield the highest energystorage per unit mass. This is one reason whycarbon fiber is a material of interest.

For a given design the stored energy isproportional to the hoop stress and the volume:

http://en.wikipedia.org/wiki/File:Flywheel_at_Tsomo.jpg

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VIBRATION IN ENGINE

An internal combustion engine produces power in theform of controlled explosions. These explosions producepowerful pulses of energy that cause the engine tovibrate in response. Engine designers do their best tomake these forces cancel out to minimize vibrations. But,

no matter how well the designer does his job, he cannoteliminate all inherent vibrations in an engine. Thereforewe need to remember that it is perfectly normal for an IC(Internal combustion) engine to produce a characteristicvibration spectrum signature. Vibration analysis of ICengines then must focus on "variations" from the"normal" vibration signature.

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CONTINUE

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LIMITATIONS OF ENGINESmall-scale energy conversion devices are being developed for a variety of

applications. Notable are propulsion units for micro-aircraft vehicles (MAV). In spite ofthe fact that batteries have low energy density, batteries today power most of themicro aircrafts. Their low energy density significantly limits the aircraft performances.The high specific energy of hydrocarbon and hydrogen fuels, as compared to otherenergy storing means, like, batteries, elastic elements, flywheels, pneumatics, andfuel cells, appears to be an important advantage, and favors the internal-combustion-engine (ICE) as a candidate. In addition, the specific power (power per unit of mass)of the ICE is much higher than that of other candidates like fuel cells, photovoltaic,

and battery units. Micro-engines are not simply smaller versions of full-size engines.Physical processes such as combustion, gas exchange, and heat transfer, areperformed in regimes different from those occur in full-size engines. Consequently,engine design principles are different at a fundamental level, and have to be re-considered before they are applied to micro-engines. When a spark-ignition (Sl) cycleis considered, part of the energy that is released during combustion is used to heat-up the mixture in the quenching volume, and therefore the flame-zone temperature islower and in some cases can theoretically fall below the self-sustained combustion

temperature. The flame quenching thus seems to limit the minimum dimensions of aSI engine. This limit becomes irrelevant when a homogeneous-charge compression-ignition (HCCI) cycle is considered. In this case friction losses and charge leakagethrough the cylinder-piston gap become dominant, constrain the engine size, andimpose minimum engine speed limits. In the present work a phenomenological modelhas been developed to consider the relevant processes inside the cylinder of ahomogeneous-charge compression-ignition (HCCI) engine. The lower possible limitsof scaling-down HCCI cycle engines are proposed. The present work postulates the

inter-relationships between the pertinent parameters, and proposes the lowerpossible miniaturization limits of IC engines.

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ADVANTAGES

There are other advantages to this scheme besides "novibration".One is the option to 'cut' the channel in amanner other than a sine wave. For instance, one mightwant the piston to linger at the top of the compression

stroke in order to allow for more complete burning of thefuel before using the energy on the downstroke. It mightbe possible to tweak some more efficiency out of internalcombustion.

The piston and piston rod are one solid unit eliminating

"sideslap". It might also be possible to lay the enginesideways and mount two pistons on the same rodthereby creating a size minimized eight cylinder engine(all pistons running on the same sine track).

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CONTINUE

The camshaft is easier to machine being now a platemounted on top to the engine connected directly to themain shaft. (It can also double as the flywheel.) As thedrum turns, raised metal on the plate activates thevalves which can be accelerated to open and closed

positions at any desired rate.This can be a very light engine. No counter weigths arerequired on the crankshaft for example. I estimate thesize of a stock four cylinder engine to be about 12" x 12"x 18" which means you could probably pick it up and

carry it to the basement for maintenance by yourself (...though I wouldn't personally advise it). An 8 cyl. enginemounted sideways wouldn't be much larger ~ 12" x 12" x24" .

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THANK YOUGUIDED BY

MR- ABHISHAKE PANDY SIR

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