Simulation Of Characteristics Of Pressure Fluctuation In The Common Rail Of CRS

With the development of Diesel Engines, the requirement of injection pressure, injection law and speed of response in FIs is increasingly high. The invention of high pressure common-rail injection system met these requirements.Thus, the study of CR system is very necessary. The structure of CR system is so complex that it’s too hard to measure the pressure in it by experiment. But as the development of computer and CFD software it is possible that make a scrutiny into CR system through the method of simulation. In this thesis, which combine the one-dimensional and multi-dimensional of CR system, completed the work below:Made the simulation of CR system and finished the analysis of characteristics of pressure fluctuation during the injection using Hydsim. Reseach the influence which the parameters of high pressure pump, common rail, injector and high pressure pipes to the pressure fluctuation and flow of diesel during injection.Build the multi-dimensional model of the flow of diesel in the common rail and simulated the real boundary using user defined function in Fluent. Analysed the characteristics of pressure fluctuation in the common rail by studying the velocity distribution and pressure dictribution in it.Research the influence which rail volume, draw ratio and interface position and section shape of common rail make on the pressure fluctuation and flow of diesel oil in the common rail using multi-dimensional model.Research the influence which oil supply parameters make on the pressure fluctuation and flow of diesel in the common rail using multi-dimensional model and find the way to decrease the pressure fluctuation and increase output velocity of diesel in the common rail.