研究直喷式柴油机碳粒排放及缸内辐射传热的一种数学方法(英文)

A Mathematical Method to Study the Soot Emission and the Heat Radiation Transfer in DI Diesel Engine Cylinder

本文给出了预测直喷式柴油机碳粒排放及碳粒和气体辐射传热的实用化数学模型。该模型以多区燃烧模型为基础,通过补充各区的碳粒和气体浓度,碳粒和气体发射率等的计算子模型,使程序功能获得扩大。用这个模型对一台实际柴油机不同喷油正时下的碳粒排放作预测,结果与实测值相吻合。本文还给出了预测和部分实测的低散热柴油机碳粒排放及碳粒和气体辐射传热的变化结果。在低散热柴油机中,碳粒排放将下降,但辐射传热量与总传热量之比会增加。

A mathematical model to predict soot emission,soot and gas heatradiation transfer in DI diesel engines was developed on the basis of amultizone combustion model with two submodels—soot formation and oxida-tion submodel and soot and gas emissivities calculation submodel.Using thismodel the soot emission of an actual diesel engine at different injectiontiming was calculated,good agreement was achieved between these computa-tions and the test data.The model was also applied to predict the soot emis-sion,soot and gas heat radiation from low heat rejection(LHR)dieselengine and resulted in that the soot emission decreased while the ratio ofthe heat radiation to total heat transfer increased significantly with theincrease of percentage reduction of heat transfer.