The mold pressing process was applied to investigate the formability of closed-cell aluminum foam in solid–liquid–gas coexisting state.Results show that the shape formation of closed-cell aluminum foam in the solid...The mold pressing process was applied to investigate the formability of closed-cell aluminum foam in solid–liquid–gas coexisting state.Results show that the shape formation of closed-cell aluminum foam in the solid–liquid–gas coexisting state was realized through cell wall deformation and cell movement caused by primary α-Al grains that slid,rotated,deformed,and ripened within cell walls.During formation,characteristic parameters of closed-cell aluminum foam were almost unchanged.Under proper forming conditions,shaped products of closed-cell aluminum foam could be fabricated through mold pressing.展开更多
An accurate prediction of the critical gas velocity for the liquid loading is of great importance for operators to select the tubing diameter for the newly drilled gas wells,or to optimize the production rate for prod...An accurate prediction of the critical gas velocity for the liquid loading is of great importance for operators to select the tubing diameter for the newly drilled gas wells,or to optimize the production rate for production wells.It is clear from previous experimental studies of the liquid entrainment rate in the gas core that the liquid is mainly carried in the form of film under the critical condition of the liquid loading onset.It is more reasonable to establish a mathematical model based on the film reversal rather than based on the droplet reversal.In our previous paper entitled“Prediction of the critical gas velocity of liquid unloading in the horizontal gas well”,a new analytical model was established based on the force balance between the gas-liquid interfacial friction force and the bottom film gravity,but the model is not very convenient to use because of the complexity of calculating the average film thickness.In the present study,a new method is proposed to calculate the average film thickness from the bubble drift velocity in the mixture,so the new analytical model becomes much easier to use.The new analytical model is evaluated against 103 sets of experimental data,the data in 124 vertical gas wells and one horizontal gas well.Meanwhile,the effect ofthe liquid loading on the production of the horizontal gas well is also analyzed.展开更多
Liquid foam is a dense random packing of gas or liquid bubbles in a small amount of immiscible liquid containing surfactants. The liquid within the Plateau borders, although small in volume, causes considerable diffic...Liquid foam is a dense random packing of gas or liquid bubbles in a small amount of immiscible liquid containing surfactants. The liquid within the Plateau borders, although small in volume, causes considerable difficulties to the investigation of the spatial structure and physical properties of foams, and the situation becomes even more com-plicated as the fluid flows. To solve these problems, a discrete model of two-dimensional liquid foams on the bubble scale is proposed in this work. The bubble surface is represented with finite number of nodes, and the liquid within Plateau borders is discretized into lattice particles. The gas in bubbles is treated as ideal gas at constant temperatures. This model is tested by choosing an arbitrary shape bubble as the initial condition. This then automatically evolves into a cir-cular shape, which indicates that the surface energy minimum routine is obeyed without calling external controlling con-ditions. Without inserting liquid particle among the bubble channels, periodic ordered and disordered dry foams are both simulated, and the fine foam structures are developed. Wet foams are also simulated by inserting fluid among bubble channels. The calculated coordination number, as a function of liquid fractions, agrees well with the standard values.展开更多
基金financially supported by the National Natural Science Foundations of China (No.51371104)
文摘The mold pressing process was applied to investigate the formability of closed-cell aluminum foam in solid–liquid–gas coexisting state.Results show that the shape formation of closed-cell aluminum foam in the solid–liquid–gas coexisting state was realized through cell wall deformation and cell movement caused by primary α-Al grains that slid,rotated,deformed,and ripened within cell walls.During formation,characteristic parameters of closed-cell aluminum foam were almost unchanged.Under proper forming conditions,shaped products of closed-cell aluminum foam could be fabricated through mold pressing.
基金supported by the National Natural Science Foundation of China(Grant No.No.51974263).
文摘An accurate prediction of the critical gas velocity for the liquid loading is of great importance for operators to select the tubing diameter for the newly drilled gas wells,or to optimize the production rate for production wells.It is clear from previous experimental studies of the liquid entrainment rate in the gas core that the liquid is mainly carried in the form of film under the critical condition of the liquid loading onset.It is more reasonable to establish a mathematical model based on the film reversal rather than based on the droplet reversal.In our previous paper entitled“Prediction of the critical gas velocity of liquid unloading in the horizontal gas well”,a new analytical model was established based on the force balance between the gas-liquid interfacial friction force and the bottom film gravity,but the model is not very convenient to use because of the complexity of calculating the average film thickness.In the present study,a new method is proposed to calculate the average film thickness from the bubble drift velocity in the mixture,so the new analytical model becomes much easier to use.The new analytical model is evaluated against 103 sets of experimental data,the data in 124 vertical gas wells and one horizontal gas well.Meanwhile,the effect ofthe liquid loading on the production of the horizontal gas well is also analyzed.
文摘Liquid foam is a dense random packing of gas or liquid bubbles in a small amount of immiscible liquid containing surfactants. The liquid within the Plateau borders, although small in volume, causes considerable difficulties to the investigation of the spatial structure and physical properties of foams, and the situation becomes even more com-plicated as the fluid flows. To solve these problems, a discrete model of two-dimensional liquid foams on the bubble scale is proposed in this work. The bubble surface is represented with finite number of nodes, and the liquid within Plateau borders is discretized into lattice particles. The gas in bubbles is treated as ideal gas at constant temperatures. This model is tested by choosing an arbitrary shape bubble as the initial condition. This then automatically evolves into a cir-cular shape, which indicates that the surface energy minimum routine is obeyed without calling external controlling con-ditions. Without inserting liquid particle among the bubble channels, periodic ordered and disordered dry foams are both simulated, and the fine foam structures are developed. Wet foams are also simulated by inserting fluid among bubble channels. The calculated coordination number, as a function of liquid fractions, agrees well with the standard values.
