How to calculate power of Main Engine (2 stroke engine)?

Indicated Power of Unit = Pm L A N

Unit of Final Result

Indicated Power = P_m L A N

= ( a / l ) x k [bar] x L [m] x A [m²] x N [1/s]
= [bar] x [m] x [m²] x [1/s]
= 10⁵ N/m2 x m x m2 x 1/s
= 10⁵ Nm/s
= 10⁵ Joules/s
= 10⁵ Watts

Hence, multiply the result obtained from calculating indicated power with 10⁵ and the final unit will be in Watts.

Note 1:  The above equation is valid for 2 stroke engine. For 4 stroke engine, divide N by 2 as there is one power stroke every two revolution of shaft.

Note 2:  On modern engines this diagram can be continuously taken by employing two transducers, one pressure transducer in the combustion space and other transducer on the shaft. Through the computer we can thus get on line indicated diagram and power of all cylinders. The equipment consists of a pressure transducer which screws onto the indicator cock which is connected to the processing unit. A crankshaft position detector is also fitted to the prop shaft or engine flywheel which measures the crank angle to 0.25°.