Multi-dimensional Modeling And Numerical Investigating The Atomization And Emissions Behavior From HSDI Diesel Engine Instantaneously

The main purpose in present paper is to develop a simulation tool for the design and research of internal combustion engine, and to explore the theory and method for improving fuel utilization and reducing the harmful emissions, to overcome the increasing energy sources shortage and environment pollution. The research included such 5 subprojects as grid arithmetic, multi-dimensional model, CAE/CAD integration, fuel atomization and the emissions of NOx and SOOT.Firstly, moving grid formation arithmetic of the complex in-cylinder space are presented, and the preprocessor for multidimensional model is developed. To obtain it, four steps were taken as follows: 1) a step was give in which the in-cylinder is divided into the moving and static zones for grid computation respectively. 2) The approach how to add or reduce grids in the moving direction of moving zones was presented. 3) A reshaping arithmetic was given to the grid computation in the section of in-cylinder. 4) An excursion arithmetic to the moving grid computation of in-cylinder with tilted valves was introduced.Secondly, a multi-dimensional model is built by coupling many sub models describing the physics and chemistry phenomena of in-cylinder into in-cylinder fluid dynamics code: KIVA, and by improving it. After presenting double precision arithmetic, a simulation tool: ICFD-CN is completed that runs on personal computer to analyze the in-cylinder process of internal combustion engine. The results from tests show that the in-cylinder pressure, the heat release ratio(HRR), and the brake specific fuel consumption(BSFC) were predicted, and a good agreement between predicted and measured data was gained by implementing the multi-dimensional model. In addition, the trend of the NOx and SOOT emissions was predicted accurately according to the results by simulating.Thirdly, a visualization system is developed for multi-dimensional simulation of internal combustion engine, and the postscript computation and visualization are implemented, so the CAE/CAD integration is realized by carrying out five efforts. After picking up and transferring approaches of the data were presented that was produced by simulation in the order of content-time-space, the contour and hide grid were computed by applying special contour and hide arithmetic. The design means of a key graphic files was given for data transformation while the CAE/CAD integration is needed, and the code used for visualization as post scripting were developed. In addition, the infinite and finite name modes about graphic files were finished.Moreover, a method is presented to analyze the atomization of spray and emissions by multi-dimensional simulating tool. By simulating the atomization behavior of spray in in-cylinder of 1137 type diesel engine, the distribution of spray in different state according to time and site is acquired, the numerical relation is founded among the atomization, combustion and emissions. Finally, after computing the emissions of 1137 type diesel engine by multidimensional model, the distribution of NOx and SOOT in time and site, its formation and oxidation history, as well as the influence of a number of design parameters on it are also gained.In conclusion, grid arithmetic in present paper should be recommended in the CAE of engine and the numerical computing of other fields. The multidimensional model will be an available tool in the design and research of engine, and a valuable support to energy saving and environment protecting in china, as well as powerful driving force to such science field as computer simulation, numerical analyzing and computing fluid dynamics.The results of third sub-project will be not only an important support to the CAE of HSDI diesel engine, but also of other engine, other engineering field and computer application.The results of the fourth and final sub-project will become a valuable approaches and provide available strategy to promote fuel utilization and meet emissions standard. In addition, these methods will be applicable in the analyzing of other exhaust pollutant, and in research on atomization and emissions from other internal combustion engines. It should be especially recommended because of less investment of test facilities and low cost in the special operation conditions.