Verdichtungszündung

Verdichtungszündung, also known as compression ignition, is a process by which a fuel ignites due to the heat generated by the compression of air in an internal combustion engine. Unlike spark ignition engines, which rely on a spark plug to initiate combustion, compression ignition engines do not have spark plugs.

The principle behind Verdichtungszündung is based on the relationship between pressure, temperature, and the autoignition temperature of a fuel. In a compression ignition engine, air is drawn into the cylinder and then compressed to a very high pressure and temperature. This compression significantly raises the temperature of the air, often exceeding the autoignition temperature of the fuel.

When fuel is injected into the hot, compressed air, it rapidly ignites spontaneously. The ignition is not instantaneous throughout the fuel charge but rather starts at the point where the fuel and air mixture first reaches its autoignition temperature. This ignition process then propagates through the rest of the fuel-air mixture, leading to combustion and the generation of power.

Verdichtungszündung is the fundamental operating principle of diesel engines. The high compression ratios achieved in diesel engines are necessary to generate the heat required for autoignition. This method of ignition is generally more efficient than spark ignition, particularly at higher loads and speeds, and allows for the use of fuels with higher cetane numbers, which are more prone to spontaneous ignition.