This paper investigated the bubble migration and evolution during gas-liquid flow in oil-pipelines. Multi-scale bubbles migrated in the pipe while interacting with each other, causing coalescence and disintegration. The bubbles collided and coalesced, forming a new air pocket in the downward inclined pipe that blocked the transportation of both the gas and liquid phases. Consequently, the buoyance weakened the migration ability of the bubbles, which is known as re-coalescence. To investigate, a new transient model applied with the population balance model (PBM), and Eulerian-Lagrangian coupling scheme is proposed. The complex flow field was modeled using the Eulerian scheme, while the migration of the bubbles was designed in the Lagrangian mesh. Furthermore, the PBM was employed to describe the multi-scale bubble interaction and migration. Smooth particle hydrodynamics were applied to connect the bubble-dimension and pipe-dimension descriptions. Therefore, the bubble fraction could be described to predict the re-coalescence of air pockets. The required unknown model parameters were extracted from the published experimental data, while the simulation results corresponded well with the measured results. During the simulation, the effect of the liquid Froude number and pipe inclination on the size distribution of the multi-scale bubbles were investigated. The results indicated that an increase in the pipe inclination and liquid Froude number improved the bubble migration capacity, leading to a broader distribution of bubbles of all sizes.

本文研究了油气管道中气液流动过程中气泡的迁移和演化。多尺度气泡在彼此相互作用的同时在管道中迁移，从而导致聚结和分解。气泡碰撞并聚结，在向下倾斜的管道中形成新的气穴，从而阻碍了气相和液相的传输。因此，浮力削弱了气泡的迁移能力，这被称为重新聚结。为了研究这一问题，提出了一种新的瞬态模型，该模型与人口平衡模型（PBM）结合使用，并提出了欧拉-拉格朗日耦合方案。使用欧拉方案对复杂的流场进行建模，而气泡的迁移则在拉格朗日网格中进行设计。此外，PBM被用来描述多尺度气泡相互作用和迁移。应用了光滑的粒子流体动力学来连接气泡尺寸和管道尺寸的描述。因此，可以描述气泡分数以预测气穴的重新聚结。从公开的实验数据中提取了所需的未知模型参数，而模拟结果与实测结果非常吻合。在模拟过程中，研究了液体弗洛德数和管道倾角对多尺度气泡尺寸分布的影响。结果表明，管道倾角和弗洛德数的增加改善了气泡的迁移能力，从而导致各种尺寸气泡的分布更加广泛。气泡分数可以用来预测气穴的重新聚结。从公开的实验数据中提取了所需的未知模型参数，而模拟结果与实测结果非常吻合。在模拟过程中，研究了液体弗洛德数和管道倾角对多尺度气泡尺寸分布的影响。结果表明，管道倾角和弗洛德数的增加改善了气泡的迁移能力，从而导致各种尺寸气泡的分布更加广泛。气泡分数可以用来预测气穴的重新聚结。从公开的实验数据中提取了所需的未知模型参数，而模拟结果与实测结果非常吻合。在模拟过程中，研究了液体弗洛德数和管道倾角对多尺度气泡尺寸分布的影响。结果表明，管道倾角和弗洛德数的增加改善了气泡的迁移能力，从而导致各种尺寸气泡的分布更加广泛。研究了液体弗洛德数和管道倾角对多尺度气泡尺寸分布的影响。结果表明，管道倾角和弗洛德数的增加改善了气泡的迁移能力，从而导致各种尺寸气泡的分布更加广泛。研究了液体弗洛德数和管道倾角对多尺度气泡尺寸分布的影响。结果表明，管道倾角和弗洛德数的增加改善了气泡的迁移能力，从而导致各种尺寸气泡的分布更加广泛。