The document outlines key performance parameters of internal combustion (IC) engines, including indicated power, brake power, and frictional power. It also explains various efficiencies such as indicated thermal efficiency, brake thermal efficiency, and mechanical efficiency, as well as concepts like calorific value and fuel-air ratio. Each parameter is defined with relevant formulas to illustrate their significance in the performance of IC engines.

1. Performance Parameters of
IC Engines

2. Explanation
The explanation of Performance parameters of IC engines is as follows.
1.Indicated power (I.P):
The total Power developed by the combustion of the fuel in the combustion chamber is called as Indicated power.
2.Break power (B.P):
The Power developed by an engine at the output shaft is called break power.
B.P=[2πNT/60]*1000 KW
3.Frictional power (F.P):
The difference between Indicated Power(I.P) and Brake Power(B.P) is called frictional power (F.P).
F.P=I.P-B.P

3. 4.Indicated Thermal Efficiency (ηith):
It is defined as the ratio of energy in the indicated power, to the input fuel energy in appropriate units.
ηith = I.P/(mass of fuel*Calorific value of fuel)
= I.P/(mf*CV)
5.Brake Thermal Efficiency (ηbth):
It is defined as the ratio of energy in the brake power, to the input fuel energy in appropriate units.
ηbth = B.P/(mass of fuel*Calorific value of fuel)
= B.P/(mf*CV)
6.Mechanical Efficiency (ηm):
It is defined as the ratio of Brake Power (delivered power) to the Indicated Power (power provided to the piston).
ηm = B.P/I.P

4. 7.Volumetric Efficiency (ηv):
It is defined as the ratio of the volume of air actually inducted at ambient conditions to the swept volume of the engine.
ηv = Vol.of air actually inducted/Swept Volume
8.Relative Efficiency or Efficiency ratio(ηrel):
It is defined as the ratio between actual thermal efficiency to the ideal efficiency (air standard efficiency) of the cycle
employed.
ηrel = Actual thermal efficiency/ideal efficiency (air standard efficiency)
9.Calorific Value:
It is the thermal energy released per unit quantity of the fuel when the fuel is burned completely and the products of
combustion are cooled back to the initial temperature at the combustion mixture.

5. 10.Mean Effective Pressure:
It is defined as the average pressure inside the cylinders of an I.C engine based on the calculated or measured power
output.
11.Specific Power Output:
It is defined as the broken output per unit of piston displacement.
12.Fuel-air Ratio:
It is defined as the ratio of the mass of the fuel to the mass of the air in the air-fuel mixture.
This is the detailed explanation of Performance Parameters of IC Engines.

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