Fuel Injection Characteristics in Diesel Engines With effects of Pressure Wave
In this paper, the results and discussion of experimental investigations on a HSDI light-duty are presented for
evaluating and analysing effects of main adjustable parameters of the fuel injection system on all regulated emissions gases
and torque performance. Main injection timing, rail pressure, pilot amount and particularly pilot timing have been examined.
The results show that optimization of each of those adjustable parameters is beneficial for emission reduction and torque
improvement under different operating conditions. By exploring the variation of the interval between the pilot injection and
the main injection, it is found that the pressure wave in the common rail produces has a significant influence on the
subsequent injection. This suggests that special attentions must be paid for adjusting pilot timing or any injection interval
when multi-injection is used. With analysing the fuel amount oscillation of the subsequent injections to pilot separation, it
demonstrates that the frequency of regular oscillations of the actual fuel amount or the injection pulse width with the
variation of pilot separation is always same for a specified fuel injection system, regardless of engine speed, fuel amount,
injection pulse, injection pressure.
Keywords - Diesel Engine, Common Rail Fuel Injection, High Pressure, Pressure Wave, Multiply Injection.