A Study On Spray Characteristics Of Transient High-Pressure Fuel Injection And The Design Of Test Platform

In order to solve the energy and environmental problems caused by ship transport,the International Maritime Organization has proposed increasingly stringent emission standard.The diesel spray mixing characteristics determine the diesel ignition and combustion characteristics,thereby affecting the performance and emissions of diesel engines.With the application of multiple injections and strategies,the spray characteristics of diesel micro-injection have become a research hotspot,and its mixing characteristics have been paid more and more attention.In this thesis,a one-dimensional discrete spray model was used to describe the spray process after the end of the spray.Base on the analysis of energy and momentum analysis,and according to the actual situation of fuel injection and the need of spray mixing process analysis,this thesis aims to add the calculation models of the fuel injection rate,penetration,entrainment rate,and the Fortran language was use for programming.Then the spray characteristics calculation with varying injection rate was realized.According to the existing experimental parameters,the simulation study of the diesel spray mixing characteristics under different injection pressure and different fuel injection conditions was carried out,and the tendencies of the spray mixing characteristics related to injection rates were obtained.The spray development process was summarized and the mixing characteristics of the spray after the end of the injection were obtained.The design of the existing constant volume combustion chamber system is optimized.Through the pressure test of constant volume combustion chamber,the existing problems were found and the simulation and analysis are carried out by establishing the 3D model of the relevant parts and introducing it into ANSYS Workbench Program.A set of high pressure common rail visualization test bed was designed by combining the simulation data and the experimental requirements of high pressure micro-injection Based on the actual situation of the test-bed,the test-bed was divided into two parts:the schlieren image system and the common rail system.And the components of these two systems were selected and designed respectively.