Research of Rail Pressure Characteristics of Common Rail Fuel System

The control of the rail pressure is quite important for a common rail (CR) fuel system since the precise rail pressure control is the basis of optimization for many controlling parameters for CR fuel system, and has a great impact on engine power and emissions. This paper presents the experimental investigation of rail pressure characteristics of a CR fuel system. The rail pressure was tested in varied operation conditions with different boundaries and control parameters. The transient rail pressure characteristics were acquired. Furthermore, the pressure fluctuation was analyzed by means of frequency-domain method. This research shows that the pressure fluctuation in the fuel rail is induced by fuel pump and injectors but not the flow measurement unit.