Which ignition type relies on heat generated by the compression of air?

The ignition type that relies on heat generated by the compression of air is compression ignition. This process is fundamental to how certain types of internal combustion engines, particularly diesel engines, operate. In compression ignition engines, air is compressed to such a high pressure that its temperature rises significantly. When fuel is injected into this hot, compressed air, it ignites spontaneously without the need for a spark plug.

This principle is in contrast to spark ignition engines, which rely on a spark plug to create an electric spark that ignites the fuel-air mixture. While diesel ignition is often used synonymously with compression ignition, compression ignition is the broader term that encompasses the mechanism itself. Turbo ignition is not a recognized type of ignition; rather, it refers to the use of a turbocharger to increase engine efficiency, but does not pertain to the type of ignition system used. Understanding the distinctions between these ignition types is essential for grasping the different operating mechanisms of engines.