Rail pressure fluctuation is a response caused by periodic excitation of the fuel in the system caused by continuous pulsating fuel supply from the high-pressure oil pump and intermittent injection from the fuel injector.The generation mechanism of pressure fluctuation in the common rail pipe is analyzed.Based on the continuity equation and momentum equation of unsteady fuel flow,the hyperbolic partial differential equation characterizing the rail pressure fluctuation is derived.The system state matrix is obtained by discretizing the partial differential equation through numerical difference method.The change rate of fuel pump supply pressure and injector injection pressure is taken as the sys-tem input variable,and the pressure fluctuation at different positions of the common rail pipe is taken as the system output variable.The pressure fluctuation characteristics of the system were analyzed using the state space method.Comparing the calculation results with experimental measurement data,the re-sults indicate that the established nonlinear numerical model can accurately characterize the characteris-tics of rail pressure fluctuations.
关键词
共轨/轨压/非线性/预测模型
Key words
common rail/rail pressure/non linearity/prediction model
维普
万方数据