Kompressioonsüüdet

Kompressioonsüüdet, also known as compression ignition, is a process in internal combustion engines where the fuel-air mixture ignites spontaneously due to the high temperature and pressure generated by compressing the air. This is in contrast to spark ignition engines, where an external spark plug initiates combustion.

In a compression ignition engine, typically a diesel engine, air is drawn into the cylinder and then compressed to a very high degree. This compression significantly raises the temperature of the air. As the piston nears the top of its stroke, fuel is injected directly into the hot, compressed air. The high temperature of the air causes the injected fuel to auto-ignite, leading to rapid combustion and expansion of gases, which drives the piston downwards.

The efficiency of compression ignition engines is generally higher than that of spark ignition engines due to the higher compression ratios employed. This higher efficiency translates into better fuel economy. However, compression ignition engines typically produce more noise and vibrations compared to spark ignition engines, and they can also emit higher levels of certain pollutants like nitrogen oxides and particulate matter, though modern engine designs and emission control systems have significantly mitigated these issues. The principle of compression ignition is fundamental to the operation of diesel engines used in a wide range of applications, from heavy-duty trucks and buses to locomotives and ships.