The degree of fuel atomization in a diesel engine cylinder depends primarily on what factor?

The degree of fuel atomization in a diesel engine cylinder is primarily influenced by the size of the holes in the fuel nozzle. The nozzle's orifice size determines how finely the fuel is broken into droplets as it is injected into the combustion chamber. Smaller nozzle holes typically create more finely atomized fuel, which enhances the surface area for combustion. This improved atomization leads to more efficient mixing with air, resulting in better combustion performance.

While other factors, such as the timing of the pump and the supply pressure to the pump, play roles in overall fuel delivery and engine performance, the direct influence on the atomization quality comes from the nozzle design. The combustion chamber shape does affect how well the air and fuel mix, but it is the nozzle's hole size that primarily dictates the atomization process itself. This makes the size of the holes in the fuel nozzle a crucial element in achieving optimal fuel atomization in diesel engines.