The Numerical Simulation Of Soot Formation And Oxidation In The Direct Injection Diesel Engine Based On The KIVA3

The soot formation affects the emissions of the diesel engine in the process of combustion directly. Researching the soot formation and oxidation has great function in the emission controlling and the fuel consumption reducing. The computer numerical simulation can realize the visualization of analyses and has the excellence of more information and low cost.In the paper, KIVA3 is applied in the numerical simulation of the soot formation and oxidation for the D6114-type diesel. The output data of KIVA3 is transplanted to the post-process software by the interface code, which can be displayed.The main work is to analyze the mechanism of the soot formation and oxidation, and search for a method for the visualization of the research results. The mechanism and the structure of the KIVA3 code have been deep analyzed. The numerical simulation of the soot formation and oxidation is carried on at the condition of fixed parameters, with the purpose of validating the correctness and the feasibility of the model.A chemical model with six reaction equations is created, the Surovikin's soot formation model, the NSC (Nagle and Strickland-Constable) soot oxidation model and the Neoh's soot oxidation model are integrated into the KIVA3. The mesh of the combustion chamber is generated by the preprocessor, the soot number density scheme and the soot mass scheme are obtained, the process of the fuel spray and soot particles changing process are also gained.There are two parts that can be gained from the result of the simulation calculation. On the one hand, the changing process rule of the soot formation and oxidation is obtained at the high temperature, high pressure and lacking of oxygen. On the other hand, the effect of the mesh plotted by the preprocessor and the feasibility of the interface code can be estimated. The mechanism of chemical reaction and the soot model which was put up in the paper can clearly explain processes of the soot formation and oxidation, and provide guidance to researching the combustion and emission in the diesel engine.