Correct Answer - Option 2 : engine friction loss
Explanation:
Engine Performance Parameters:
Indicated Power:
- It is the power developed inside the engine cylinder.
- \(I.P = \frac{{{p_m}LANK}}{{60}}\)
Brake Power:
- This is the actual power available at the crankshaft and may be called the power output of the engine. It is always less than indicated power.
- \(B.P = \frac{{2\pi NT}}{{60}}\)
Friction Power:
- It is the power loss in overcoming the friction between piston and cylinder walls, between the crankshaft and camshaft and their bearings, etc.
- It is the difference between Indicated power and Brake power.
- F.P = I.P - B.P
Indicated thermal efficiency:
- It is the ratio of I.P to fuel power.
- \({\eta _{ith}} = \frac{{I.P}}{{{{\dot m}_f} \;\times\; CV}}\)
Brake thermal efficiency :
- It is the ratio of B.P to fuel power.
- \({\eta _{bth}} = \frac{{B.P}}{{{{\dot m}_f} \;\times \;CV}}\)
Mechanical Efficiency :
- It is the ratio of brake power to indicated power.
- \({\eta _m} = \frac{{B.P}}{{I.P}} = \frac{{{\eta _{bth}}}}{{{\eta _{ith}}}}\)
