Working of Internal combustion Engines

 Internal Combustion Engines are the engines used in transport vehicles like cars, buses, trucks, motor cycles, and so on. Here, a fuel is burned, and the energy from the burning fuel is transferred to the pistons, which through gears, turn the wheels, thus moving the automobile.

In petrol engines, the fuel air - mixture after being compressed is ignited by an electric spark, hence the name spark Ignition (S.I) engine, and the products of combustion do work on the piston, and through crank-and-connecting-rod mechanism, power is transferred to the crank shaft. In diesel Engines, only air is inducted by suction into cylinder and compressed to a high pressure. The fuel is injected in fine atomized form into the hot compressed air. The mixture get self-ignited and the combustion products do work in the pistons. These are called compression ignition (C.I) Engines. 

Thermodynamic analysis seeks to determine how much work we may expect from an engine and, through experiments, how efficiently the engine is performing. This is very important if the pollution from exhausts is to be minimized. 

The gas turbine is another automotive power source, more commonly found in Jet planes. There is an upsurge in the development of gas turbine plants in both electric power generation and ship propulsion. Air is compressed and energy added to it by burning fuel in a combustion chamber; this mixture, viz., the products of  combustion, expands through a turbine, doing a work, which drives the electric generator or the ship. The analysis is similar to that of most power plants, and all these analyses have a common purpose, which is to consider how efficiently the chemical energy of the fuel is converted into mechanical energy. The processes of converting the energy are different, but the principle of energy conversion remains the same.