The Numerical Simulation Of Soot's Form Course By Experiential Model In Diesel Engine

Soot are formed when fuel molecule split in high temperature,short of oxygen and high pressure condition in diesel engine's burning course. The soot not only badly pollute the environment, but also bring harm to human's health. So the rule to diesel engine's exhaust are more stricter than before, and the control to diesel engine's exhaust has become one of important and hot question about diesel engine's capability research.In this paper, K&G model and Guangan amend model are adopted, the two representative models are experiential soot predicted model. Then use the two models to simulate the soot's form course. In the simulation, the rate of soot are programmed by C language and incorporate into the CFD code to construct a multidimensional mode, then analysis the temperature fied's variety to soot's influence in formation and oxidation.The paper is divided into two parts. In the first part, the two models are simulated in a multidimensional steady firebox. In the same condition, compare the two model's soot formation result, and provide reference for the after simulation in the soot model parameter's select. The result indicate that in the steady status, the total amount of soot mass calculated by K&G model is 35 to 43 percent more than Guangan's model.In the second part of the paper, the two models are used to simulate the diesel engine's burning process. The simulation calculate air-fuel ratio,intake temperature,crankshaft and turbulent model and so on influence to soot formation and oxidation. The result indicate that: compare the two model's result to experiment result separately, the Guangan model's error rate is 10-30 percent, but the K&G model's error rate is 20-38 percent.The simulation indicate that: the maximum of soot mass is increased by the air-fuel ratio's increase and the initial temperature increase under the same condition. The simulation results also show that: the maximum of soot mass is less than standard model, and the time of maximum of soot formation is later about 1°CA crank angle if using RNG turbulent model.