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Theory of machine| part -1

Kinematics links - Every part of machine which have relative motion to another part.   → The link should be resistance body.   What is resistant body? →Under the action of force it can transfer motion and power. Kinematics links →1. Rigid links     2. Flexible links     3. Fluid links Rigid links - There is no deformation.   Ex - piston,connecting rod Flexible links - Deformation is allowed under permissible limits. Ex - Belt drive Fluid links - A fluid link is one that is deformed by having fluid in a closed vessel and the motion is transmitted through the fluid by pressure. Ex - Hydraulic press   Types of links - 1. Singular 2. Binary 3. Ternary 4. Quaternary links
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                            I.C ENGINE
HERE WE KNOW ABOUT CARNOT CYCLE,we already discuss in thermodynamics cheptra history behind carnnot cycle and details about this plz check the link :
https://engineerapk.blogspot.in/2017/11/history-behind-carnot-cycle-details-of.html?m=1

OTTO CYCLE :
Basic of otto cycle ; 
* This cycle was introduced by german scientists Dr. A.N. Otto.
* It is successfully aplied on petrol engine.
* It consist two reversible adiabetic process & two constant volume process.
* This is six event cycle -
                A. Suction
                B. Compression
                C. Combustion
                D. Expansion
                E. Blow by(heat rejected)
                F. Exahust

 Theory of otto cycle

Process (0 - 1) suction of the air fuel mixture in cycle.
Process (1 - 2) adiabetic compression.
Process (2 - 3) compress volume of heat addition.
Process (3 - 4) adiabetic expansion.
Process (4 - 1) constant volume heat rejection.
Process (1 - 0) piston go to TDC exhaust.

Otto cycle : 4 stroke, 6 event
                   Works on  S.I engine.
                    Fuel : gasoline (petrol)
Here four strokes are : A. Suction B. Compression C. Power D. Exaust
* combustion and blow by ( heat rejected) are instantaneous event.

Suction(0°-180°): Inlet valve open, exhaust value closed, piston moves T.D.C to B.D.C.
low pressure area created in CC(combustion chamber), CC is filled with fresh air.

Compression(180°-360°) : piston moves B.D.C. to T.D.C.
Fresh charge gets compresed.

Combustion : crank in postion 360°.Its a instantaneous process,heat addition.

Expansion(360°-540°): piston goes T.D.C. to B.D.C. Both valve are closed.

Blow by : Crank angle 540°.its a instantaneous Process.exhaust valve gets open.burn gases are excape from cc.heat rejection.

Exaust(540°-720°):exhaust valve open.burn gases out from cc.
* suction stroke - constant pressure Process.
*compression stroke- reversible adiabetic compression process.
*combustion - its a instantaneous process.constant volume.heat addition.
*expansion - reversible adiabetic expansion.
* blow by - constant volume heat rejection.
*exhaust - constant pressure process.

Effiency of Air Standar Otto Cycle :
        η = 1 - (1/r)^γ - 1
From this above expansion it is obvious that greater the compression ratio,higher will be the air standard cycle efficiency.
* Efficiency is indipendent of heat supplied and pressure ratio.
* Efficiency is measure by the increasing of compression ratio.

 ** NOTE THAT WHO ARE INTERESTED IN WBPSC EXAM.LAST DATE OF SUBMIT 3RD JAN 2018.
I.c engine: carnnot cycle,otto cycle,6 event,4stroke details
https://www.pscwbonline.gov.in/apps/login/login.html

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