Turbulent Flow Characteristics and Modeling on Dispersed Two-Phase Flow

分散两相流的湍流特性和建模

• 批准号: 03452125
• 负责人: MAEDA Masanobu
• 金额: $ 2.82万
• 依托单位: Keio University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-03452125/
• 关键词: Two-phase Flow; Gas-solid flow; Particle dispersion; LDV measurement; レーザ流速計; レ-ザ流速計

An experiment study has been carried out concerning the dispersion of solid particles in a wake region of a pair of circular cylinders. Two cylinders were arranged in parallel, where the distance s between cylinders were set at s/d=0.3 and 2.0, and the air velocity around the cylinders at 10m/s. Spherical grass particles of 42mum in mean diameter were loaded at the center of the space between the cylinders.For the single-phase flow, large scale eddy was observed in the wake region by the flow visualization. Strouhal number varied with the distance between the cylinders.For the two-phase flow, the particles began to disperse after reaching the flow region of the wake over the wide distance between the cylinders. Under the condition, the particles disperse gradually because the flow field has no vortex interaction. For the narrow gap between the cylinders, the particles dispersed rapidly. The flow field has an interaction between the vertices in the wake region. A large entrainment force act on the particles while the vertices interact with each other. The Stokes number, which is defined as the ratio of particle relaxation time and characteristic time scale of the large scale vortex, is confirmed to be a dominant factor for the particle dispersion.

对双圆柱尾流区固体颗粒的弥散进行了实验研究。两个圆柱体平行布置，其中圆柱体之间的距离s设定为s/d=0.3和2.0，并且圆柱体周围的空气速度为10 m/s。实验中，在圆柱间的中心位置放置了平均直径为42 μ m的球形草颗粒，通过流动显示，在单相流的尾迹区观察到了大尺度的涡.对于两相流，颗粒到达尾迹区后，在较宽的柱间距范围内开始分散。在此条件下，由于流场没有涡的相互作用，颗粒逐渐分散。由于筒体之间的间隙较窄，颗粒分散较快。流场在尾流区域中的顶点之间具有相互作用。当顶点相互作用时，大的卷吸力作用在颗粒上。Stokes数定义为粒子弛豫时间与大尺度涡旋特征时间尺度的比值，它被证实是粒子弥散的主导因素。

项目成果

Ishima,T.,Hishida,K.and maeda,M: "Effect of Particle Residence Time on Particle Dispersion." ASME Jourmal of Fluid Engineering.

Ishima,T.、Hishida,K. 和 maeda,M：“颗粒停留时间对颗粒分散的影响”。

K.Hishida,A.Ando and M.Maeda: "Experiments on particle dispersion in a turbulent mixing layer" Int.J.Multiphase.

K.Hishida、A.Ando 和 M.Maeda：“湍流混合层中粒子分散的实验”Int.J.Multiphase。

Ishima,T.,Hishida,K.and Maeda,M: "Effect of Particle Residence Time on Particle Dispersion." ASME Journal of Fluid Engineering(1993年12月).

Ishima, T.、Hishida, K. 和 Maeda, M：“颗粒停留时间对颗粒分散的影响”。ASME 流体工程杂志（1993 年 12 月）。

T.Ishima,K.Hishida and M.Maeda: "Effect of particle residence time on particle dispersion in a plane mixing layer" Trans.ASME J.Fluid Engineering.

T.Ishima、K.Hishida 和 M.Maeda：“颗粒停留时间对平面混合层中颗粒分散的影响”Trans.ASME J.Fluid Engineering。

Ishima,T., Hishida,K. and Maeda,M.: ""Effect of Particle Residence Time on Particle Dispersion,"" Transactions of the ASMEJFE.

石岛，T.，菱田，K.