Experimental and numerical study on the effects of the solenoid valve motion on the fuel pressure fluctuations for electronic unit pump systems of diesel engines

For electronic unit pump systems, it is an advantage for online combustion analysis and fault diagnosis to ascertain the relationship between the fuel pressure fluctuation and the movement of the solenoid valve. We experimentally and numerically investigated the fuel pressure characteristics and their connection to the transient motion of the solenoid valve. Four fuel pressure characteristic points corresponding to the start of closing time, the fully closed time, the start of opening time and the fully opened time of the solenoid valve were determined on the fuel pressure curve. A novel method was proposed to predict the solenoid valve displacement curve based on the four fuel pressure characteristic points. The validation results show that the displacement curves of the prediction and experiment are almost coincident, and the relative error of the injection quantity per cycle between the simulation and experiment is within 3 %.