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Internal combustion engines produce mechanical power from the chemical energy contained in

the fuel, as a result of the combustion process occurring inside the engine. The internal

combustion engine converts chemical energy of the fuel into mechanical energy, usually made

available on a rotating output shaft. Chemical energy of the fuel is first converted into thermal

energy by means of combustion or oxidation with air inside the engine, raising the temperature

and pressure of the gases within the combustion chamber. The high pressure gas expands and

by mechanical mechanism rotates the crankshaft, which is the output of the engine. The

crankshaft is connected to a transmission to transmit the rotating mechanical energy to drive a

vehicle. Most of the internal combustion engines are reciprocating engines with a piston that

reciprocate back and forth in the cylinder. The combustion process takes place in the cylinder.

Heat transfer in internal combustion engines is a very serious problem since need high

temperatures to combust the fuel but also need to keep the temperature of engine at a

controllable level in order to operate the engine safely. Once the engine has reached intolerable

values the engine block and the components may suffer damage. Therefore it is essential to

have a heat removal process which will maintain the engine at a safe operating condition.

Power in engine is produced by burning fuel in which gives heat. The power produced in the

cylinder of the engine is called indicated power. The indicated power is also calculated from

indicator diagram Brake power is that which is obtained from crankshaft of the engine. The

different between indicated power and brake power is the power lost in friction of various

moving parts. This friction power is required to move the engine when it is hot producing any

power. Evaluating engine performance is to attach the engine output shaft to a device known asa dynamometer or brake. The dynamometer measures the torque, T, applied by the engine at a

given rotational speed.

A brake men effective pressure (BMEP) may be defined that, when multipled by the engine

displacement and speed, yields the brake power. The thermal efficiency, as for other engines, is

a measure of the fuel economy of a reciprocating engine. It tells the amount of power output

that can be achieved for a given rate of heat release from the fuel.

If the thermal efficiency is evaluated using the brake power, it is called the brake thermal

efficiency (BTE).

It is common practice in the reciprocating engine field to report engine fuel economy in terms of

a parameter called the specific fuel consumption (SFC) similar to the thrust specific fuel

consumption used to describe jet engine performance. The specific fuel consumption is defined

as the ratio of the fuel-mass flow rate to the power output.

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Principle of engine operation

http://web.itu.edu.tr/~sorusbay/ICE/index_files/LN01.pdf

Principle of IC engines

http://www.ignou.ac.in/upload/unit-2.pdf

http://web.itu.edu.tr/~sorusbay/ICE/index_files/LN01.pdfhttp://web.itu.edu.tr/~sorusbay/ICE/index_files/LN01.pdfhttp://www.ignou.ac.in/upload/unit-2.pdfhttp://www.ignou.ac.in/upload/unit-2.pdfhttp://www.ignou.ac.in/upload/unit-2.pdfhttp://web.itu.edu.tr/~sorusbay/ICE/index_files/LN01.pdf