ABSTRACT
An internal combustion engine, which is a heat engine, produces mechanical power by converting chemical energy into heat energy and then mechanical power. Thermodynamics is a branch of physical science that deals with relations between heat and other forms of energy. A spark-ignition engine operates with the thermodynamic cycle of an Otto cycle, whereas a compression-ignition engine operates with a constant pressure cycle/dual cycle. A compression-ignition engine operates with a constant pressure cycle. Air from the atmosphere is only inducted during the suction stroke and then it is compressed during the compression stroke. A two-stroke engine is a type of internal combustion engine that completes a power cycle with every two strokes. Automotive vehicles are mostly used for mass and passenger transportation. The speed, power, and torque of engine/vehicle may vary based on its payload and traffic conditions. Exhaust gas recirculation (EGR) is a technique to reduce oxides of nitrogen (NOx) at source level in spark-ignition engines and compression-ignition engines.
