微粒羽流自由降落过程特性的探讨

根据自由下落微粒羽流的运动特征,对微粒羽流自由下落过程中卷吸空气的机理进行初步分析,应用Tomom i给出的混合微粒模型及Ogata给出的单微粒模型与环境空气卷吸量实验值进行对比分析.结果表明,混合微粒模型对环境空气卷吸量的模拟值与实验值有较好的吻合性,而Ogata给出的单微粒模型预测值低于实测值.实验结果表明,环境空气卷吸量随着微粒羽流下降高度的延伸而增加,随着微粒流中微粒的密度及粒径的增大而减小.

Primary Investigation of Air Entrainment in Free Falling Particle Plumes

Accroding to the characteristics of the free falling particle plume,the mechanism of the air entrainment in the process of free falling particles is analyzed preliminarily.The Tomomi miscible particle model and the Ogata non-miscible particle model are discussed in comparison with the experimental data of the quantity of the entrained surrounding air.The results indicate that the simulation of the miscible particle model to predict the volume of air entrainment has a good agreement with the experimental data.But the predicted value from the Ogata's non-miscible particle model is lower than the obtained data in testing. The experimental results indicate that the volume of the ambient air entrainment increases with the drop-height extension of the particle plume and decreases with the increase of the particle diameter and density.