Search Results

This paper discusses the performance of the radial plunger pump used in the contemporary diesel common-rail fuel systems for rail-pressure supply. On the ground of the pump mechanism, the transient flow, drive torque, and efficiency of the pump are analyzed for various operation conditions. The analysis shows that the number of plungers and utilization of the pump capacity govern fluctuations in the pump discharge. The pump flow can be characterized by a discharge function which applies to both full- and part-capacity pump flows. At the full pump capacity, the discharge fluctuation is determined solely by the number of plungers: a pump with an odd number of plungers has more ripples and lower amplitudes in its discharge than a pump with an even number of plungers does. A pump operates at a part capacity has more fluctuations in the discharge than when at the full capacity.

Cavitation induced cylinder liner erosion can be a significant durability problem in high power density diesel engines. It is typically discovered in the field, thus causing costly redesigns. The application of a predictive simulation to analyze the liner cavitation process upfront could identify the problem early on and enable significant savings. Hence, this work investigates the ability of the computational fluid dynamics (CFD) multiphase flow simulation tool to handle vibration induced cavitation. A flow of liquid through a U-shaped duct is analyzed, where a middle segment of the duct is set to vibrate in a manner resembling vibration of the cooling jacket walls in an internal combustion engine. Velocity, pressure and vapor concentration fields are tracked for two cases, distinguished by different frequencies of duct wall vibration.