The optimization of flow control devices(FCDs) for a T-type five-strand billet caster tundish was carried out by water modeling and numerical simulation. In water modeling experiments, flow characteristics of the bare...The optimization of flow control devices(FCDs) for a T-type five-strand billet caster tundish was carried out by water modeling and numerical simulation. In water modeling experiments, flow characteristics of the bare tundish and tundish conf igurations with designed U-type baff les and a round turbulence inhibitor were analyzed using residence time distribution(RTD) curves. Mathematical models for liquid steel in the real plant tundish were established using the fluid dynamics software package Fluent. The flow field, the temperature field, and the RTD curves of liquid steel in the proposed tundish conf igurations were obtained. The results of numerical simulation and water modeling were validated with each other by the predicted and experimental RTD curves. The results of flow field and temperature field were used to ref lect the actual state of a real plant tundish and to choose the optimal FCD. Finaly, from the whole performance of the multi-strand tundish, the optimal scheme was determined by combining the results of water modeling and numerical simulation. With the optimal tundish equipped with U-type baffle with def lector holes and round turbulence inhibitor, not only was the flow characteristic of each strand improved, but also the difference of flow characteristics between multiple strands was smaller.展开更多
Liquid sloshing is a common phenomenon in the liquid tanks transportation. Liquid waves lead to fluctuating forces on the tank wall. Uncontrolled fluctuations lead to large forces and momentums. Baffles can control th...Liquid sloshing is a common phenomenon in the liquid tanks transportation. Liquid waves lead to fluctuating forces on the tank wall. Uncontrolled fluctuations lead to large forces and momentums. Baffles can control these fluctuations. A numerical method, which has been widely used to model this phenomenon, is Smoothed Particle Hydrodynamics(SPH). The Lagrangian nature of this method makes it suitable for simulating free surface flows. In the present study, an accurate Incompressible Smoothed Particle Hydrodynamics(ISPH) method is developed and improved using the kernel gradient correction tensors, particle shifting algorithms, k–ε turbulence model, and free surface particle detectors. Comparisons with the experimental data approve the ability of the present algorithm for simulating shallow water sloshing. The main aim of this study is to investigate the effects of the vertical baffle on the damping of liquid sloshing. Results show that baffles number has a major role in sloshing fluctuation damping.展开更多
Through the research on several carbonate reservoirs developed in the Middle East, the basic characteristics of different types of carbonate reservoirs are determined, and a set of high-efficiency water injection deve...Through the research on several carbonate reservoirs developed in the Middle East, the basic characteristics of different types of carbonate reservoirs are determined, and a set of high-efficiency water injection development options and strategies are presented. Hidden baffles and barriers exist in carbonate reservoirs in the Middle East, so the reservoirs could be divided into different separated development units based on the baffles and barriers characteristics. Flexible and diverse profile control techniques such as high angle wells and simple and applicative zonal water injection have been introduced to improve the control and development degree of reservoirs. Three principal water injection development methods suitable for different carbonate reservoirs in the Middle East are proposed, including the combination of crestal gas injection and peripheral water injection, bottom interval injection and top interval production(buoyancy underpinning), and "weak point and strong plane" area well pattern. Based on the characteristics of very low shale content, fast and far pressure transmission in the Middle East carbonate reservoirs, a large well-spacing flood pattern is recommended, and reasonable development strategies have been made such as moderate water injection rate and maintaining reasonable production pressure drawdown and voidage replacement ratio, so as to maximize the recovery of reservoirs in the none or low water cut period.展开更多
The fluid flow phenomena in tundish have a strong influence not only on theuniform of composition and temperature of bath, but also on the separation of non-metallicinclusions, especially for the multi-strand tundish....The fluid flow phenomena in tundish have a strong influence not only on theuniform of composition and temperature of bath, but also on the separation of non-metallicinclusions, especially for the multi-strand tundish. A water model of a multi-strand tundish hasbeen set up based on the Froude number and Reynold number similarity criteria. The effect ofdam+weir and baffle on the uniform of composition and temperature of bath for different nozzles hasbeen studied. The residence time distribution curves of the fluid flow were measured by SG800.Comparing the photos of the flow pattern in tundish, the optimum arrangement of baffle+dam wasobtained. This new structure is benefit not only to uniform the temperature among different SENs(submerge entry nozzles) but also to separate the non-inclusions from the liquid steel, it can bewidely used in multi-strand tundish.展开更多
The purpose of the study is to analyze the reduction effects of multi-baffle installed for improving the scour issue of weir downstream and the study reviewed the flow reduction effect for the location of the battle a...The purpose of the study is to analyze the reduction effects of multi-baffle installed for improving the scour issue of weir downstream and the study reviewed the flow reduction effect for the location of the battle and the reduction effect associated with the baffle installation. We carried out nine cases of experiments and analyzed reduction effects through the flow rate comparison for the arrangement type of the cases. As the result of the experiment, the maximum flow rate in the weir downstream of the case 1, which has no baffle installation, is measured at 2.068 m/s due to multidirectional flow and crossing waves, and channel walls had whirlpool generation on the left and right with fast discharge flow. The maximum water level showed lower water level than when the battle was installed as there is no flow resistance. The maximum stream velocity in the weir downstream from cases 2 to 9 installed with a baffle demonstrated reduction in the maximum stream velocity than before the battle was installed and showed an increased tendency than before the baffle was installed as the maximum water level is affected by flow resistance. As the result of the comparison of the reduction effect by installing the baffle, the V type of the case 6 demonstrated the best reduction effect.展开更多
t A series of inline pico hydropower systems,which could be used in confined space,especially for water distribution networks(WDNs),was designed and investigated.The turbine with an eye-shaped vertical water baffle wa...t A series of inline pico hydropower systems,which could be used in confined space,especially for water distribution networks(WDNs),was designed and investigated.The turbine with an eye-shaped vertical water baffle was developed to evaluate the hydraulic performance.A three-dimensional dynamic mesh was employed and the inlet velocity was considered as the inlet boundary condition,whereas the outlet boundary was set as the outflow.Then,numerical simulations were conducted and the standard k-εturbulence model was found to be the best capable of predicting flow features through the comparison with the experimental results.The effects of the opening diameter of the water baffle and installation angle of the rotor on the flow field in the turbine were investigated.The results suggested that the water baffle opening at d=30 mm and the rotor at a 52°angle could achieve the highest efficiency of 5.93%.The proper eye-shaped baffle not only accelerates the fluid flow and generates positive hydrodynamic torque,but also eliminates the flow separation.The scheme proposed in this paper can be exploited for practical applications in the water pipelines at various conditions and power requirements.展开更多
基金financially supported by the National Natural Science Foundation of China(51504002)
文摘The optimization of flow control devices(FCDs) for a T-type five-strand billet caster tundish was carried out by water modeling and numerical simulation. In water modeling experiments, flow characteristics of the bare tundish and tundish conf igurations with designed U-type baff les and a round turbulence inhibitor were analyzed using residence time distribution(RTD) curves. Mathematical models for liquid steel in the real plant tundish were established using the fluid dynamics software package Fluent. The flow field, the temperature field, and the RTD curves of liquid steel in the proposed tundish conf igurations were obtained. The results of numerical simulation and water modeling were validated with each other by the predicted and experimental RTD curves. The results of flow field and temperature field were used to ref lect the actual state of a real plant tundish and to choose the optimal FCD. Finaly, from the whole performance of the multi-strand tundish, the optimal scheme was determined by combining the results of water modeling and numerical simulation. With the optimal tundish equipped with U-type baffle with def lector holes and round turbulence inhibitor, not only was the flow characteristic of each strand improved, but also the difference of flow characteristics between multiple strands was smaller.
文摘Liquid sloshing is a common phenomenon in the liquid tanks transportation. Liquid waves lead to fluctuating forces on the tank wall. Uncontrolled fluctuations lead to large forces and momentums. Baffles can control these fluctuations. A numerical method, which has been widely used to model this phenomenon, is Smoothed Particle Hydrodynamics(SPH). The Lagrangian nature of this method makes it suitable for simulating free surface flows. In the present study, an accurate Incompressible Smoothed Particle Hydrodynamics(ISPH) method is developed and improved using the kernel gradient correction tensors, particle shifting algorithms, k–ε turbulence model, and free surface particle detectors. Comparisons with the experimental data approve the ability of the present algorithm for simulating shallow water sloshing. The main aim of this study is to investigate the effects of the vertical baffle on the damping of liquid sloshing. Results show that baffles number has a major role in sloshing fluctuation damping.
文摘Through the research on several carbonate reservoirs developed in the Middle East, the basic characteristics of different types of carbonate reservoirs are determined, and a set of high-efficiency water injection development options and strategies are presented. Hidden baffles and barriers exist in carbonate reservoirs in the Middle East, so the reservoirs could be divided into different separated development units based on the baffles and barriers characteristics. Flexible and diverse profile control techniques such as high angle wells and simple and applicative zonal water injection have been introduced to improve the control and development degree of reservoirs. Three principal water injection development methods suitable for different carbonate reservoirs in the Middle East are proposed, including the combination of crestal gas injection and peripheral water injection, bottom interval injection and top interval production(buoyancy underpinning), and "weak point and strong plane" area well pattern. Based on the characteristics of very low shale content, fast and far pressure transmission in the Middle East carbonate reservoirs, a large well-spacing flood pattern is recommended, and reasonable development strategies have been made such as moderate water injection rate and maintaining reasonable production pressure drawdown and voidage replacement ratio, so as to maximize the recovery of reservoirs in the none or low water cut period.
文摘The fluid flow phenomena in tundish have a strong influence not only on theuniform of composition and temperature of bath, but also on the separation of non-metallicinclusions, especially for the multi-strand tundish. A water model of a multi-strand tundish hasbeen set up based on the Froude number and Reynold number similarity criteria. The effect ofdam+weir and baffle on the uniform of composition and temperature of bath for different nozzles hasbeen studied. The residence time distribution curves of the fluid flow were measured by SG800.Comparing the photos of the flow pattern in tundish, the optimum arrangement of baffle+dam wasobtained. This new structure is benefit not only to uniform the temperature among different SENs(submerge entry nozzles) but also to separate the non-inclusions from the liquid steel, it can bewidely used in multi-strand tundish.
文摘The purpose of the study is to analyze the reduction effects of multi-baffle installed for improving the scour issue of weir downstream and the study reviewed the flow reduction effect for the location of the battle and the reduction effect associated with the baffle installation. We carried out nine cases of experiments and analyzed reduction effects through the flow rate comparison for the arrangement type of the cases. As the result of the experiment, the maximum flow rate in the weir downstream of the case 1, which has no baffle installation, is measured at 2.068 m/s due to multidirectional flow and crossing waves, and channel walls had whirlpool generation on the left and right with fast discharge flow. The maximum water level showed lower water level than when the battle was installed as there is no flow resistance. The maximum stream velocity in the weir downstream from cases 2 to 9 installed with a baffle demonstrated reduction in the maximum stream velocity than before the battle was installed and showed an increased tendency than before the baffle was installed as the maximum water level is affected by flow resistance. As the result of the comparison of the reduction effect by installing the baffle, the V type of the case 6 demonstrated the best reduction effect.
文摘t A series of inline pico hydropower systems,which could be used in confined space,especially for water distribution networks(WDNs),was designed and investigated.The turbine with an eye-shaped vertical water baffle was developed to evaluate the hydraulic performance.A three-dimensional dynamic mesh was employed and the inlet velocity was considered as the inlet boundary condition,whereas the outlet boundary was set as the outflow.Then,numerical simulations were conducted and the standard k-εturbulence model was found to be the best capable of predicting flow features through the comparison with the experimental results.The effects of the opening diameter of the water baffle and installation angle of the rotor on the flow field in the turbine were investigated.The results suggested that the water baffle opening at d=30 mm and the rotor at a 52°angle could achieve the highest efficiency of 5.93%.The proper eye-shaped baffle not only accelerates the fluid flow and generates positive hydrodynamic torque,but also eliminates the flow separation.The scheme proposed in this paper can be exploited for practical applications in the water pipelines at various conditions and power requirements.
