湍流燃烧模型对直喷式柴油机火焰结构和排放物预测的影响研究

研究了不同湍流燃烧模型（EBU、CTC和PaSR模型）对直喷式柴油机燃烧过程中火焰结构和排放物生成的影响。分析了缸内平均量（放热率、缸内平均温度、NO和soot）变化情况和OH、NO及soot分布，并与试验结果进行了对比分析。研究结果表明：不同燃烧模型虽然能得到相近的缸内平均量结果，但预测得到的缸内OH、NO、soot分布和温度分布情况存在一定差异；其中以EBU模型的预测结果与试验偏离最大；PaSR模型能较准确预测缸内变量微观分布情况和火焰脱离喷孔的距离，其预测得到的火焰结构与Dec1997年提出的概念模型一致。

Effects of Various Turbulence Combustion Models on Prediction of Flame Configuration and Emissions in a DI Diesel Engine

Effects of various combustion models(EBU,CTC and PaSR model) on the flame lift-off length and combustion characteristics in a DI diesel engine were investigated.The mean in-cylinder values(heat release rate, in-cylinder mean temperature) computed by the three combustion models were analyzed.Predicted OH,NO and soot distributions were compared with experimental results.The study showed that there were a great difference in the predicted in-cylinder OH,NO,soot and temperature distributions of various combustion models,although the calculated mean in-cylinder values were almost identical.The analysis also showed that EBU model was the worst predicted results.Parameters in cylinder,and the flame configuration predicted by PaSR model were similar to that of Dec's 1997 "conceptual" model.