SKEDSOFT

Introduction:

The performance of an engine is usually studied by heat balance-sheet.

COMPONENTS OF THE HEAT BALANCE:

The main components of the heat balance are :

•  Heat equivalent to the effective (brake) work of the engine,
•  Heat rejected to the cooling medium,
•  Heat carried away from the engine with the exhaust gases, and
• Unaccounted losses.

The unaccounted losses include the radiation losses from the various parts of the engine and heat lost due to incomplete combustion. The friction loss is not shown as a separate item to the heat balance-sheet as the friction loss ultimately reappears as heat in cooling water, exhaust and radiation

Uncontrolled Otto Engine

Performance of SI Engine at Constant Speed and Variable Load