In a Morse test for 2-cylinder,2-stroke SI engne, the brake power was 15KW whereas the brake power of single cylinder when spark was cut off were 6.5 KW and 5.5 KW. What will be the mechanical efficiency of the engine?

 

In a Morse test for 2-cylinder,2-stroke SI engne, the brake power was 15KW  whereas the brake power of single cylinder when spark was cut off were 6.5 KW and 5.5 KW. What will be the mechanical efficiency of the engine?

Solution-

Given,

Brake power of all cylinder , B=15KW

Brake power of cylinder 1, `B_1`= 6.5KW

Brake power of cylinder 1,`B_2` = 5.5KW

Now , We know that

The Indicated power, IP= (B-`B_1`) + (B-`B_2`)=15-6.5+15-5.5=18KW

 

So, Mechanical Efficiency ,=`n_m`=B/IP=0.833 or 83.33%

Hence , the mechanical efficiency of the engine will be 83.33%