Numerical simulations of evolution characteristics of slug flow across a 90°pipe bend have been carried out to study the fluid−structure interaction response induced by internal slug flow.The two-phase flow patte...Numerical simulations of evolution characteristics of slug flow across a 90°pipe bend have been carried out to study the fluid−structure interaction response induced by internal slug flow.The two-phase flow patterns and turbulence were modelled by using the volume of fluid(VOF)model and the Realizable k−εturbulence model respectively.Firstly,validation of the CFD model was carried out and the desirable results were obtained.The different flow patterns and the time-average mean void fraction was coincident with the reported experimental data.Simulations of different cases of slug flow have been carried out to show the effects of superficial gas and liquid velocity on the evolution characteristics of slug flow.Then,a one-way coupled fluid-structure interaction framework was established to investigate the slug flow interaction with a 90°pipe bend under various superficial liquid and gas velocities.It was found that the maximum total deformation and equivalent stress increased with the increasing superficial gas velocity,while decreased with the increasing superficial liquid velocity.In addition,the total deformation and equivalent stress has obvious periodic fluctuation.Furthermore,the distribution position of maximum deformation and stress was related to the evolution of slug flow.With the increasing superficial gas velocity,the maximum total deformation was mainly located at the 90°pipe bend.But as the superficial liquid velocity increases,the maximum total deformation was mainly located in the horizontal pipe section.Consequently,the slug flow with higher superficial gas velocity will induce more serious cyclical impact on the 90°pipe bend.展开更多
Fluid-structure interaction(FSI)of gas-liquid two-phase fow in the horizontal pipe is investigated numerically in the present study.The volume of fluid model and standard k-e turbulence model are integrated to simulat...Fluid-structure interaction(FSI)of gas-liquid two-phase fow in the horizontal pipe is investigated numerically in the present study.The volume of fluid model and standard k-e turbulence model are integrated to simulate the typical gas-liquid two-phase fow patterns.First,validation of the numerical model is conducted and the typical fow patterns are consistent with the Baker chart.Then,the FSI framework is established to investigate the dynamic responses of the interaction between the horizontal pipe and gas-liquid two-phase fow.The results show that the dynamic response under stratified fow condition is relatively flat and the maximum pipe deformation and equivalent stress are 1.8 mm and 7.5 MPa respectively.Meanwhile,the dynamic responses induced by slug fow,wave fow and annular fow show obvious periodic fuctuations.Furthermore,the dynamic response characteristics under slug flow condition are maximum;the maximum pipe deformation and equivalent stress can reach 4mm and 17.5 MPa,respectively.The principal direction of total deformation is different under various flow patterns.Therefore,the periodic equivalent stress will form the cyclic impact on the pipe wall and affect the fatigue life of the horizontal pipe.The present study may serve as a reference for FSI simulation under gas-liquid two-phase transport conditions.展开更多
Tall towers with large diameters on floating liquefied natural gas devices are highly sensitive to sway.If tower equipment is relatively high,swaying can easily cause uneven gaseliquid contact in the tower,inhibiting ...Tall towers with large diameters on floating liquefied natural gas devices are highly sensitive to sway.If tower equipment is relatively high,swaying can easily cause uneven gaseliquid contact in the tower,inhibiting its absorption capacity.In this paper,gaseliquid counterflow triethylene glycol dehydration absorption towers are taken as the research object.A porous medium model was used to simplify the packing environment,and the EulereEuler method was used to simulate the flow field in the tower.The flow field encompasses the effects of the gaseliquid phase dispersion force,gaseliquid phase diffusion coefficient,and interphase mass transfer.By introducing a dynamic grid model to establish sway boundary conditions,we quantitatively examine the influence of sway duration and angle on gaseliquid flow and mass transfer performance in absorption towers.The results show that,when the sloshing angle of the absorption tower is 9°and the sloshing period is 20 s,the influence of the disturbance of the absorption tower's internal flow field is increased by 85%and 78%respectively compared with normal working conditions.When the sloshing angle of the absorption tower is 9°and the sloshing period exceeds 21 s,the gaseliquid mass transfer inside the absorption tower diminishes.When the sloshing period of the regeneration tower is 6 s and the sloshing angle reaches 20°,the mass fraction of poor ethylene glycol in the regeneration tower fluctuates significantly in the first sloshing cycle,and unqualified products appear.展开更多
基金sponsored by the National Natural Science Foundation of China(Grant No.51779143)the Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(Grant No.SL2020ZD101)the Cultivation of Scientific Research Ability of Young Talents of Shanghai Jiao Tong University(Grant No.19X100040072).
文摘Numerical simulations of evolution characteristics of slug flow across a 90°pipe bend have been carried out to study the fluid−structure interaction response induced by internal slug flow.The two-phase flow patterns and turbulence were modelled by using the volume of fluid(VOF)model and the Realizable k−εturbulence model respectively.Firstly,validation of the CFD model was carried out and the desirable results were obtained.The different flow patterns and the time-average mean void fraction was coincident with the reported experimental data.Simulations of different cases of slug flow have been carried out to show the effects of superficial gas and liquid velocity on the evolution characteristics of slug flow.Then,a one-way coupled fluid-structure interaction framework was established to investigate the slug flow interaction with a 90°pipe bend under various superficial liquid and gas velocities.It was found that the maximum total deformation and equivalent stress increased with the increasing superficial gas velocity,while decreased with the increasing superficial liquid velocity.In addition,the total deformation and equivalent stress has obvious periodic fluctuation.Furthermore,the distribution position of maximum deformation and stress was related to the evolution of slug flow.With the increasing superficial gas velocity,the maximum total deformation was mainly located at the 90°pipe bend.But as the superficial liquid velocity increases,the maximum total deformation was mainly located in the horizontal pipe section.Consequently,the slug flow with higher superficial gas velocity will induce more serious cyclical impact on the 90°pipe bend.
基金the National Natural Science Foundation of China(No.51779143)the Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(No.SL2020ZD101)the Cultivation of Scientific Research Ability of Young Talents of Shanghai Jiao Tong University(No.19X100040072)。
文摘Fluid-structure interaction(FSI)of gas-liquid two-phase fow in the horizontal pipe is investigated numerically in the present study.The volume of fluid model and standard k-e turbulence model are integrated to simulate the typical gas-liquid two-phase fow patterns.First,validation of the numerical model is conducted and the typical fow patterns are consistent with the Baker chart.Then,the FSI framework is established to investigate the dynamic responses of the interaction between the horizontal pipe and gas-liquid two-phase fow.The results show that the dynamic response under stratified fow condition is relatively flat and the maximum pipe deformation and equivalent stress are 1.8 mm and 7.5 MPa respectively.Meanwhile,the dynamic responses induced by slug fow,wave fow and annular fow show obvious periodic fuctuations.Furthermore,the dynamic response characteristics under slug flow condition are maximum;the maximum pipe deformation and equivalent stress can reach 4mm and 17.5 MPa,respectively.The principal direction of total deformation is different under various flow patterns.Therefore,the periodic equivalent stress will form the cyclic impact on the pipe wall and affect the fatigue life of the horizontal pipe.The present study may serve as a reference for FSI simulation under gas-liquid two-phase transport conditions.
基金funded by a project of the Ministry of Industry and Information Technology of the People's Republic of China(“Research on the key technology of treatment processes for high-flow offshore natural gas,”CJ09N20).
文摘Tall towers with large diameters on floating liquefied natural gas devices are highly sensitive to sway.If tower equipment is relatively high,swaying can easily cause uneven gaseliquid contact in the tower,inhibiting its absorption capacity.In this paper,gaseliquid counterflow triethylene glycol dehydration absorption towers are taken as the research object.A porous medium model was used to simplify the packing environment,and the EulereEuler method was used to simulate the flow field in the tower.The flow field encompasses the effects of the gaseliquid phase dispersion force,gaseliquid phase diffusion coefficient,and interphase mass transfer.By introducing a dynamic grid model to establish sway boundary conditions,we quantitatively examine the influence of sway duration and angle on gaseliquid flow and mass transfer performance in absorption towers.The results show that,when the sloshing angle of the absorption tower is 9°and the sloshing period is 20 s,the influence of the disturbance of the absorption tower's internal flow field is increased by 85%and 78%respectively compared with normal working conditions.When the sloshing angle of the absorption tower is 9°and the sloshing period exceeds 21 s,the gaseliquid mass transfer inside the absorption tower diminishes.When the sloshing period of the regeneration tower is 6 s and the sloshing angle reaches 20°,the mass fraction of poor ethylene glycol in the regeneration tower fluctuates significantly in the first sloshing cycle,and unqualified products appear.
