Internal combustion engines

In an internal combustion engine, power production is achieved by the combustion of the fuel and air mixture. Here engine design is very easy and simple since boilers and condensers are not required. The other advantages are minimum loss due to heat transfer and no requirement of cooling system. There exist many ways of classification of internal combustion engines. They are based on thermodynamic cycle, number of strokes per cycle, ignition system, fuel used, cooling arrangement and arrangement of cylinders. In thermodynamic cycle, three types exist. They are constant volume or otto cycle, constant pressure or diesel cycle and limited pressure or dual cycle. In otto cycle, heat energy is added to the system at constant volume and in diesel cycle, heat energy addition is at constant pressure. In dual cycle engines, heat energy is added partly at constant volume and partly at constant pressure. Based on number of strokes per cycle, there exist two categories- 4 stroke engine and 2 stroke engine. Based on ignition system, there exist three categories-spark ignition, compression ignition and pilot injection engines. Based on fuel used, there exist four categories- petrol engine, oil engine (diesel engine), gas engine and multifuel engine. Based on cooling arrangement, there exist two categories- water cooled and air cooled engines. Based on the arrangement of cylinders, there exist four categories- in-line engine, V-engine, opposed piston engine and radial engine.