Advantages of using multi-hole injector over single hole injector when used in a CI engine
One of the reason for using multi-hole injectors is spray dispersion due to large spray cone angle achieved due to the increase in the number of injector holes. As the bore diameter of CI engines is quite large, the spray needs to be very well dispersed for uniform mixture formation.
Efficient mixing of fuel & air is critical in any engine in order to obtain optimum power and fuel consumption. When using multi-hole over single-hole injectors in a diesel engine it it possible to employ smaller holes and this results in superior atomisation of the fuel and more thorough fuel/air mixing thereby generating greater efficiency.
The larger spray cone is another aspect – distributing the droplets more evenly in the volume thus resulting in a more uniform combustion.