The fluid of casting process is a typical kind of multi-phase flow. Actually, many casting phenomena have close relationship with the multi-phase flow, such as molten metal filling process, air entrapment, slag moveme...The fluid of casting process is a typical kind of multi-phase flow. Actually, many casting phenomena have close relationship with the multi-phase flow, such as molten metal filling process, air entrapment, slag movement, venting process of die casting, gas escaping of lost foam casting and so on. Obviously, in order to analyze these phenomena accurately, numerical simulation of the multi-phase fluid is necessary. Unfortunately, so far, most of the commercial casting simulation systems do not have the ability of multi-phase flow modeling due to the difficulty in the multi-phase flow calculation. In the paper, Finite Different Method (FDM) technique was adopt to solve the multi-phase fluid model. And a simple object of the muiti-phase fluid was analyzed to obtain the fluid rates of the liquid phase and the entrapped air phase.展开更多
Smoothed particle hydrodynamics(SPH)is a Lagrangian,mesh-free numerical method renowned for its ability to handle fluid dynamics problems with large interface deformations and multiphase flow coupling.This study intro...Smoothed particle hydrodynamics(SPH)is a Lagrangian,mesh-free numerical method renowned for its ability to handle fluid dynamics problems with large interface deformations and multiphase flow coupling.This study introduces an SPH-based multiphase flow model for simulating bubbly flows involving various immiscible fluids.The model uses a volume-based density discretization equation,ensuring numerical accuracy near interfaces,independent of density ratios,thus maintaining accuracy and stability even at high density ratios.By integrating the Continuous Surface Force method for surface tension into the multiphase SPH model,the study simulates interfacial behavior between phases.The model accurately predicts Laplace pressure differences across interfaces,maintaining interface stability at density ratios up to 100.0.Simulations of single and double bubble ascents elucidate the influence of the Bond number on bubble shape,rising distance,and velocity.As the Bond number increases,bubbles flatten and develop tails,affecting their integrity.The study also simulates multiple bubbles ascents in water,showcasing the model's ability to capture complex interfacial behaviors in bubbly flows,including deformation,adsorption,coalescence,and tearing.展开更多
In the petroleum industry,detection of multi-phase fluid flow is very important in both surface and down-hole measurements.Accurate measurement of high rate of water or gas multi-phase flow has always been an academic...In the petroleum industry,detection of multi-phase fluid flow is very important in both surface and down-hole measurements.Accurate measurement of high rate of water or gas multi-phase flow has always been an academic and industrial focus.NMR is an efficient and accurate technique for the detection of fluids;it is widely used in the determination of fluid compositions and properties.This paper is aimed to quantitatively detect multi-phase flow in oil and gas wells and pipelines and to propose an innovative method for online nuclear magnetic resonance(NMR)detection.The online NMR data acquisition,processing and interpretation methods are proposed to fill the blank of traditional methods.A full-bore straight tube design without pressure drop,a Halbach magnet structure design with zero magnetic leakage outside the probe,a separate antenna structure design without flowing effects on NMR measurement and automatic control technology will achieve unattended operation.Through the innovation of this work,the application of NMR for the real-time and quantitative detection of multi-phase flow in oil and gas wells and pipelines can be implemented.展开更多
In order to overcome the defects of air-agitated seed precipitation, such as scaring, liquid short-(circuiting,) the three-dimension flow fields with different structure are numerically simulated by computational flui...In order to overcome the defects of air-agitated seed precipitation, such as scaring, liquid short-(circuiting,) the three-dimension flow fields with different structure are numerically simulated by computational fluid dynamics software. Euler/Euler approach was used to study the effects of structure on the flow field in the tank. Multi-fluid model, body-fitted coordinates and multi-block gird were adopted in the simulation. The simulating results are well consonant with the practical situations. The flow field is improved obviously when the flow velocity increases from (0.089m/s) to 0.1920.300m/s at the bottom of the optimized tank and therefore the scaring is reduced greatly in the industrial production. With a gathering sill, the problem of short-circuiting, which always appeares in the upper of the tank, can be solved very well.展开更多
Extracted natural gas hydrate is a multi-phase and multi-component mixture,and its complex composition poses significant challenges for transmission and transportation,including phase changes following extraction and ...Extracted natural gas hydrate is a multi-phase and multi-component mixture,and its complex composition poses significant challenges for transmission and transportation,including phase changes following extraction and sediment deposition within the pipeline.This study examines the flow and heat transfer characteristics of hydrates in a riser,focusing on the multi-phase flow behavior of natural gas hydrate in the development riser.Additionally,the effects of hydrate flow and seawater temperature on heat exchange are analyzed by simulating the ambient temperature conditions of the South China Sea.The findings reveal that the increase in unit pressure drop is primarily attributed to higher flowvelocities,which result in increased friction of the hydrate flowwithin the development riser.For example,at a hydrate volume fraction of 10%,the unit pressure drop rises by 166.65%and 270.81% when the average inlet velocity is increased from1.0 to 3.0m/s(a two-fold increase)and 5.0 m/s(a four-fold increase),respectively.Furthermore,the riser outlet temperature rises with increasing hydrate flowrates.Under specific heat loss conditions,the flowratemust exceed a minimum threshold to ensure safe transportation.The study also indicates that the riser outlet temperature increases with higher seawater temperatures.Within the seawater temperature range of 5℃ to 15℃,the heat transfer efficiency is reduced compared to the range of 15℃ to 20℃.This discrepancy is due to the fact that as the seawater temperature rises,the convective heat transfer coefficient between the hydrate and the inner wall of the riser also increases,leading to improved overall heat transfer between the hydrate and the pipeline.展开更多
In this paper, we build up a three-dimensional model for CO2 storage in the deep reservoir. And this paper gives the mathematical formalism of combined geochemical and multi-phase flow. The results give us the informa...In this paper, we build up a three-dimensional model for CO2 storage in the deep reservoir. And this paper gives the mathematical formalism of combined geochemical and multi-phase flow. The results give us the information about geochemical changing caused by CO2 injection into aqueous, the dissolution or precipitation of reservoir minerals caused by aqueous components change, the change of water density, also the differences between this model and the simulation model without considering geochemical. The basic data for simulation is from York Reservoir.展开更多
Dust generated in mining and tunneling activities is hazardous to health of persons and safety of operations. These projects employ pick-milling machines to extract minerals and rock by mechanical breakage.The machine...Dust generated in mining and tunneling activities is hazardous to health of persons and safety of operations. These projects employ pick-milling machines to extract minerals and rock by mechanical breakage.The machines are equipped with flooded-bed scrubbers that encase dust particles within fine water films as particles encounter a flooded wire-mesh screen. A major disadvantage is that the screen gets clogged when particles become trapped within the wire mesh, reducing airflow through the scrubber and increasing ambient dust concentrations. Thus, the system requires frequent maintenance or replacement. The application of a Vortecone scrubber as an improved alternative to conventional fibrous type scrubbers is investigated. A Vortecone forces dust-laden air and water to follow a complex, rapidly swirling motion.The momentum drives dust particles towards the periphery where they are captured by the water film.The operating characteristics of a reduced-scale physical model of a Vortecone, with its primary axis mounted in the horizontal orientation, was analyzed numerically and experimentally. Computational fluid dynamics(CFD) models depicting the spraying action and multi-phase air/water flows using the volume of fraction(VOF) approach, are presented. Experimental results, utilizing an optical particle counting technique to establish the dust-cleaning capabilities of the model, are also described.展开更多
In this paper, we present an adaptive moving mesh algorithm for meshesof unstructured polyhedra in three space dimensions. The algorithm automaticallyadjusts the size of the elements with time and position in the phys...In this paper, we present an adaptive moving mesh algorithm for meshesof unstructured polyhedra in three space dimensions. The algorithm automaticallyadjusts the size of the elements with time and position in the physical domain to resolvethe relevant scales in multiscale physical systems while minimizing computationalcosts. The algorithm is a generalization of the moving mesh methods basedon harmonic mappings developed by Li et al. [J. Comput. Phys., 170 (2001), pp. 562-588, and 177 (2002), pp. 365-393]. To make 3D moving mesh simulations possible,the key is to develop an efficient mesh redistribution procedure so that this part willcost as little as possible comparing with the solution evolution part. Since the meshredistribution procedure normally requires to solve large size matrix equations, wewill describe a procedure to decouple the matrix equation to a much simpler blocktridiagonaltype which can be efficiently solved by a particularly designed multi-gridmethod. To demonstrate the performance of the proposed 3D moving mesh strategy,the algorithm is implemented in finite element simulations of fluid-fluid interface interactionsin multiphase flows. To demonstrate the main ideas, we consider the formationof drops by using an energetic variational phase field model which describesthe motion of mixtures of two incompressible fluids. Numerical results on two- andthree-dimensional simulations will be presented.展开更多
Chemical synthesis is essential in industries such as petrochemicals, fine chemicals, and pharmaceuticals, driving economic and social development. The increasing demand for new molecules and materials calls for novel...Chemical synthesis is essential in industries such as petrochemicals, fine chemicals, and pharmaceuticals, driving economic and social development. The increasing demand for new molecules and materials calls for novel chemical reactions;however, manual experimental screening is time-consuming. Artificial intelligence (AI) offers a promising solution by leveraging large-scale experimental data to model chemical reactions, although challenges such as the lack of standardization and predictability in chemical synthesis hinder AI applications. Additionally, the multi-scale nature of chemical reactions, along with complex multiphase processes, further complicates the task. Recent advances in microchemical systems, particularly continuous flow methods using microreactors, provide precise control over reaction conditions, enhancing reproducibility and enabling high-throughput experimentation. These systems minimize transport-related inconsistencies and facilitate scalable industrial applications. This review systematically explores recent developments in intelligent synthesis based on microchemical systems, focusing on reaction system design, synthesis robots, closed-loop optimization, and high-throughput experimentation, while identifying key areas for future research.展开更多
Aiming at the simulation of multi-phase flow in the wellbore during the processes of gas kick and well killing of complex-structure wells(e.g.,directional wells,extended reach wells,etc.),a database including 3561 gro...Aiming at the simulation of multi-phase flow in the wellbore during the processes of gas kick and well killing of complex-structure wells(e.g.,directional wells,extended reach wells,etc.),a database including 3561 groups of experimental data from 32 different data sources is established.Considering the effects of fluid viscosity,pipe size,interfacial tension,fluid density,pipe inclination and other factors on multi-phase flow parameters,a new gas-liquid two-phase drift flow relation suitable for the full flow pattern and full dip range is established.The distribution coefficient and gas drift velocity models with a pipe inclination range of-90°–90°are established by means of theoretical analysis and data-driven.Compared with three existing models,the proposed models have the highest prediction accuracy and most stable performance.Using a well killing case with the backpressure method in the field,the applicability of the proposed model under the flow conditions with a pipe inclination range of-90°–80°is verified.The errors of the calculated shut in casing pressure,initial back casing pressure and casing pressure when adjusting the displacement are 2.58%,3.43%,5.35%,respectively.The calculated results of the model are in good agreement with the field backpressure data.展开更多
Multiphase microfluidic has emerged as a powerful platform to produce novel materials with tailor-designed functionalities,as microfluidic fabrication provides precise controls over the size,component,and structure of...Multiphase microfluidic has emerged as a powerful platform to produce novel materials with tailor-designed functionalities,as microfluidic fabrication provides precise controls over the size,component,and structure of resultant materials.Recently,functional materials with well-defined micro-/nanostructures fabricated by microfluidics find important applications as environmental and energy materials.This review first illustrated in detail how different structures or shapes of droplet and jet templates are formed by typical configurations of microfluidic channel networks and multiphase flow systems.Subsequently,recent progresses on several representative energy and environmental applications,such as water purification,water collecting and energy storage,were overviewed.Finally,it is envisioned that integrating microfluidics and other novel materials will play increasing important role in contributing environmental remediation and energy storage in near future.展开更多
Fluid flow at nanoscale is closely related to many areas in nature and technology(e.g.,unconventional hydrocarbon recovery,carbon dioxide geo-storage,underground hydrocarbon storage,fuel cells,ocean desalination,and b...Fluid flow at nanoscale is closely related to many areas in nature and technology(e.g.,unconventional hydrocarbon recovery,carbon dioxide geo-storage,underground hydrocarbon storage,fuel cells,ocean desalination,and biomedicine).At nanoscale,interfacial forces dominate over bulk forces,and nonlinear effects are important,which significantly deviate from conventional theory.During the past decades,a series of experiments,theories,and simulations have been performed to investigate fluid flow at nanoscale,which has advanced our fundamental knowledge of this topic.However,a critical review is still lacking,which has seriously limited the basic understanding of this area.Therefore herein,we systematically review experimental,theoretical,and simulation works on single-and multi-phases fluid flow at nanoscale.We also clearly point out the current research gaps and future outlook.These insights will promote the significant development of nonlinear flow physics at nanoscale and will provide crucial guidance on the relevant areas.展开更多
This paper reviews recent progress made toward modeling of cavitation and numerical simulation of cavitating water jets. Properties of existing cavitation models are discussed and a compressible mixture flow method fo...This paper reviews recent progress made toward modeling of cavitation and numerical simulation of cavitating water jets. Properties of existing cavitation models are discussed and a compressible mixture flow method for the numerical simulation of high- speed water jets accompanied by intensive cavitation is introduced. Two-phase fluids media of cavitating flow are treated as a homo- geneous bubbly mixture and the mean flow is computed by solving Reynolds-Averaged Navier-Stokes （RANS） equations for com- pressible fluid. The intensity of cavitation is evaluated by the gas volume fraction, which is governed by the compressibility of bubble-liquid mixture corresponding to the status of mean flow field. Numerical results of cavitating water jet issuing from an orifice nozzle are presented and its applicability to intensively cavitating jets is demonstrated. However, the effect of impact pressure caused by collapsing of bubbles is neglected, and effectively coupling of the present compressible mixture flow method with the dynamics of bubbles remains to be a challenge.展开更多
A supercomputer with 1.0 Petaflops peak performance in single precision, designed and established by Institute of Process Engineering, Chinese Academy of Sciences, is introduced in this brief communication. A designin...A supercomputer with 1.0 Petaflops peak performance in single precision, designed and established by Institute of Process Engineering, Chinese Academy of Sciences, is introduced in this brief communication. A designing philosophy utilizing the similarity between hardware, software and the problems to be solved is embodied, based on the multi-scale method and discrete simulation approaches developed at Institute of Process Engineering （IPE） and implemented in a graphic processing unit （GPU）-based hybrid computing mode. The preliminary applications of this machine in areas of multi-phase flow, molecular dynamics and so on are reported, demonstrating the supercomputer as a paradigm of green computation in new architecture.展开更多
文摘The fluid of casting process is a typical kind of multi-phase flow. Actually, many casting phenomena have close relationship with the multi-phase flow, such as molten metal filling process, air entrapment, slag movement, venting process of die casting, gas escaping of lost foam casting and so on. Obviously, in order to analyze these phenomena accurately, numerical simulation of the multi-phase fluid is necessary. Unfortunately, so far, most of the commercial casting simulation systems do not have the ability of multi-phase flow modeling due to the difficulty in the multi-phase flow calculation. In the paper, Finite Different Method (FDM) technique was adopt to solve the multi-phase fluid model. And a simple object of the muiti-phase fluid was analyzed to obtain the fluid rates of the liquid phase and the entrapped air phase.
基金the State Key Laboratory of Intelligent Optimized Manufacturing in Mining&Metallurgy Process Open Research Fund(No.JTKY202404622)and(No.BGRIMM-KZSKL-2023-12).
文摘Smoothed particle hydrodynamics(SPH)is a Lagrangian,mesh-free numerical method renowned for its ability to handle fluid dynamics problems with large interface deformations and multiphase flow coupling.This study introduces an SPH-based multiphase flow model for simulating bubbly flows involving various immiscible fluids.The model uses a volume-based density discretization equation,ensuring numerical accuracy near interfaces,independent of density ratios,thus maintaining accuracy and stability even at high density ratios.By integrating the Continuous Surface Force method for surface tension into the multiphase SPH model,the study simulates interfacial behavior between phases.The model accurately predicts Laplace pressure differences across interfaces,maintaining interface stability at density ratios up to 100.0.Simulations of single and double bubble ascents elucidate the influence of the Bond number on bubble shape,rising distance,and velocity.As the Bond number increases,bubbles flatten and develop tails,affecting their integrity.The study also simulates multiple bubbles ascents in water,showcasing the model's ability to capture complex interfacial behaviors in bubbly flows,including deformation,adsorption,coalescence,and tearing.
基金supported by the National Natural Science Foundation of China(Grant No.51704327)
文摘In the petroleum industry,detection of multi-phase fluid flow is very important in both surface and down-hole measurements.Accurate measurement of high rate of water or gas multi-phase flow has always been an academic and industrial focus.NMR is an efficient and accurate technique for the detection of fluids;it is widely used in the determination of fluid compositions and properties.This paper is aimed to quantitatively detect multi-phase flow in oil and gas wells and pipelines and to propose an innovative method for online nuclear magnetic resonance(NMR)detection.The online NMR data acquisition,processing and interpretation methods are proposed to fill the blank of traditional methods.A full-bore straight tube design without pressure drop,a Halbach magnet structure design with zero magnetic leakage outside the probe,a separate antenna structure design without flowing effects on NMR measurement and automatic control technology will achieve unattended operation.Through the innovation of this work,the application of NMR for the real-time and quantitative detection of multi-phase flow in oil and gas wells and pipelines can be implemented.
基金Project(030620) supported by the Dissertation Innovation Fund of Central South University
文摘In order to overcome the defects of air-agitated seed precipitation, such as scaring, liquid short-(circuiting,) the three-dimension flow fields with different structure are numerically simulated by computational fluid dynamics software. Euler/Euler approach was used to study the effects of structure on the flow field in the tank. Multi-fluid model, body-fitted coordinates and multi-block gird were adopted in the simulation. The simulating results are well consonant with the practical situations. The flow field is improved obviously when the flow velocity increases from (0.089m/s) to 0.1920.300m/s at the bottom of the optimized tank and therefore the scaring is reduced greatly in the industrial production. With a gathering sill, the problem of short-circuiting, which always appeares in the upper of the tank, can be solved very well.
基金This work was supported by the Ministry of Industry and Information Technology High Tech Ship Special Project(Grant No.CBG3N21-2-6).
文摘Extracted natural gas hydrate is a multi-phase and multi-component mixture,and its complex composition poses significant challenges for transmission and transportation,including phase changes following extraction and sediment deposition within the pipeline.This study examines the flow and heat transfer characteristics of hydrates in a riser,focusing on the multi-phase flow behavior of natural gas hydrate in the development riser.Additionally,the effects of hydrate flow and seawater temperature on heat exchange are analyzed by simulating the ambient temperature conditions of the South China Sea.The findings reveal that the increase in unit pressure drop is primarily attributed to higher flowvelocities,which result in increased friction of the hydrate flowwithin the development riser.For example,at a hydrate volume fraction of 10%,the unit pressure drop rises by 166.65%and 270.81% when the average inlet velocity is increased from1.0 to 3.0m/s(a two-fold increase)and 5.0 m/s(a four-fold increase),respectively.Furthermore,the riser outlet temperature rises with increasing hydrate flowrates.Under specific heat loss conditions,the flowratemust exceed a minimum threshold to ensure safe transportation.The study also indicates that the riser outlet temperature increases with higher seawater temperatures.Within the seawater temperature range of 5℃ to 15℃,the heat transfer efficiency is reduced compared to the range of 15℃ to 20℃.This discrepancy is due to the fact that as the seawater temperature rises,the convective heat transfer coefficient between the hydrate and the inner wall of the riser also increases,leading to improved overall heat transfer between the hydrate and the pipeline.
基金Supported by the National Natural Science Foundation of China （50904073） and CNPC Innovation Foundation （2008D-5006-02-06）.
文摘In this paper, we build up a three-dimensional model for CO2 storage in the deep reservoir. And this paper gives the mathematical formalism of combined geochemical and multi-phase flow. The results give us the information about geochemical changing caused by CO2 injection into aqueous, the dissolution or precipitation of reservoir minerals caused by aqueous components change, the change of water density, also the differences between this model and the simulation model without considering geochemical. The basic data for simulation is from York Reservoir.
基金supported by the National Institute for Occupational Safety and Health(NIOSH)via Grant 200-2014-59922,“Coal Mine Dust Mitigation through Novel Scrubber Development and Numerical Modeling”..
文摘Dust generated in mining and tunneling activities is hazardous to health of persons and safety of operations. These projects employ pick-milling machines to extract minerals and rock by mechanical breakage.The machines are equipped with flooded-bed scrubbers that encase dust particles within fine water films as particles encounter a flooded wire-mesh screen. A major disadvantage is that the screen gets clogged when particles become trapped within the wire mesh, reducing airflow through the scrubber and increasing ambient dust concentrations. Thus, the system requires frequent maintenance or replacement. The application of a Vortecone scrubber as an improved alternative to conventional fibrous type scrubbers is investigated. A Vortecone forces dust-laden air and water to follow a complex, rapidly swirling motion.The momentum drives dust particles towards the periphery where they are captured by the water film.The operating characteristics of a reduced-scale physical model of a Vortecone, with its primary axis mounted in the horizontal orientation, was analyzed numerically and experimentally. Computational fluid dynamics(CFD) models depicting the spraying action and multi-phase air/water flows using the volume of fraction(VOF) approach, are presented. Experimental results, utilizing an optical particle counting technique to establish the dust-cleaning capabilities of the model, are also described.
基金the Joint Applied Mathematics Research Institute of Peking University and Hong Kong Baptist University.Li was also partially supported by the National Basic Research Program of China under the grant 2005CB321701The research of Tang was supported by CERG Grants of Hong Kong Research Grant Council,FRG grants of Hong Kong Baptist University,and NSAF Grant#10476032 of National Science Foundation of China.He was supported in part by the Chinese Academy of Sciences while visiting its Institute of Computational Mathematics.
文摘In this paper, we present an adaptive moving mesh algorithm for meshesof unstructured polyhedra in three space dimensions. The algorithm automaticallyadjusts the size of the elements with time and position in the physical domain to resolvethe relevant scales in multiscale physical systems while minimizing computationalcosts. The algorithm is a generalization of the moving mesh methods basedon harmonic mappings developed by Li et al. [J. Comput. Phys., 170 (2001), pp. 562-588, and 177 (2002), pp. 365-393]. To make 3D moving mesh simulations possible,the key is to develop an efficient mesh redistribution procedure so that this part willcost as little as possible comparing with the solution evolution part. Since the meshredistribution procedure normally requires to solve large size matrix equations, wewill describe a procedure to decouple the matrix equation to a much simpler blocktridiagonaltype which can be efficiently solved by a particularly designed multi-gridmethod. To demonstrate the performance of the proposed 3D moving mesh strategy,the algorithm is implemented in finite element simulations of fluid-fluid interface interactionsin multiphase flows. To demonstrate the main ideas, we consider the formationof drops by using an energetic variational phase field model which describesthe motion of mixtures of two incompressible fluids. Numerical results on two- andthree-dimensional simulations will be presented.
基金supported by the National Natural Science Foundation of China(22378227)Shijiazhuang Science and Technology Bureau(231790163A).
文摘Chemical synthesis is essential in industries such as petrochemicals, fine chemicals, and pharmaceuticals, driving economic and social development. The increasing demand for new molecules and materials calls for novel chemical reactions;however, manual experimental screening is time-consuming. Artificial intelligence (AI) offers a promising solution by leveraging large-scale experimental data to model chemical reactions, although challenges such as the lack of standardization and predictability in chemical synthesis hinder AI applications. Additionally, the multi-scale nature of chemical reactions, along with complex multiphase processes, further complicates the task. Recent advances in microchemical systems, particularly continuous flow methods using microreactors, provide precise control over reaction conditions, enhancing reproducibility and enabling high-throughput experimentation. These systems minimize transport-related inconsistencies and facilitate scalable industrial applications. This review systematically explores recent developments in intelligent synthesis based on microchemical systems, focusing on reaction system design, synthesis robots, closed-loop optimization, and high-throughput experimentation, while identifying key areas for future research.
基金Supported by the Project of National Natural Science Foundation of China(51991363,51974350)Young Changjiang Scholars Award Program(Q2016135)Ministry of Education Innovation Team Project(IRT_14R58)。
文摘Aiming at the simulation of multi-phase flow in the wellbore during the processes of gas kick and well killing of complex-structure wells(e.g.,directional wells,extended reach wells,etc.),a database including 3561 groups of experimental data from 32 different data sources is established.Considering the effects of fluid viscosity,pipe size,interfacial tension,fluid density,pipe inclination and other factors on multi-phase flow parameters,a new gas-liquid two-phase drift flow relation suitable for the full flow pattern and full dip range is established.The distribution coefficient and gas drift velocity models with a pipe inclination range of-90°–90°are established by means of theoretical analysis and data-driven.Compared with three existing models,the proposed models have the highest prediction accuracy and most stable performance.Using a well killing case with the backpressure method in the field,the applicability of the proposed model under the flow conditions with a pipe inclination range of-90°–80°is verified.The errors of the calculated shut in casing pressure,initial back casing pressure and casing pressure when adjusting the displacement are 2.58%,3.43%,5.35%,respectively.The calculated results of the model are in good agreement with the field backpressure data.
基金supported by National Natural Science Foundation of China(Grant No.52172283,22108147,22078197)Guangdong Basic and Applied Basic Research Foundation(Grant No.2021A1515012506,2023A1515011827)+1 种基金Shenzhen Science and Technology Program(JCYJ20220818095801003,RCYX20221008092902010)Shenzhen Natural Science Fund(the Stable Support Plan Program 20220810120421001).
文摘Multiphase microfluidic has emerged as a powerful platform to produce novel materials with tailor-designed functionalities,as microfluidic fabrication provides precise controls over the size,component,and structure of resultant materials.Recently,functional materials with well-defined micro-/nanostructures fabricated by microfluidics find important applications as environmental and energy materials.This review first illustrated in detail how different structures or shapes of droplet and jet templates are formed by typical configurations of microfluidic channel networks and multiphase flow systems.Subsequently,recent progresses on several representative energy and environmental applications,such as water purification,water collecting and energy storage,were overviewed.Finally,it is envisioned that integrating microfluidics and other novel materials will play increasing important role in contributing environmental remediation and energy storage in near future.
基金the funding support from the National Natural Science Foundation of China(51974013 and 11372033)the Open Research Foundation(NEPU-EOR-2019-003)the initiative funding from the University of Science and Technology Beijing.
文摘Fluid flow at nanoscale is closely related to many areas in nature and technology(e.g.,unconventional hydrocarbon recovery,carbon dioxide geo-storage,underground hydrocarbon storage,fuel cells,ocean desalination,and biomedicine).At nanoscale,interfacial forces dominate over bulk forces,and nonlinear effects are important,which significantly deviate from conventional theory.During the past decades,a series of experiments,theories,and simulations have been performed to investigate fluid flow at nanoscale,which has advanced our fundamental knowledge of this topic.However,a critical review is still lacking,which has seriously limited the basic understanding of this area.Therefore herein,we systematically review experimental,theoretical,and simulation works on single-and multi-phases fluid flow at nanoscale.We also clearly point out the current research gaps and future outlook.These insights will promote the significant development of nonlinear flow physics at nanoscale and will provide crucial guidance on the relevant areas.
基金supported by the Japan Society for the Promotion of Science (JSPS), Grant-in-Aid for Scientific Research (C) (Grant No. 22560177)
文摘This paper reviews recent progress made toward modeling of cavitation and numerical simulation of cavitating water jets. Properties of existing cavitation models are discussed and a compressible mixture flow method for the numerical simulation of high- speed water jets accompanied by intensive cavitation is introduced. Two-phase fluids media of cavitating flow are treated as a homo- geneous bubbly mixture and the mean flow is computed by solving Reynolds-Averaged Navier-Stokes （RANS） equations for com- pressible fluid. The intensity of cavitation is evaluated by the gas volume fraction, which is governed by the compressibility of bubble-liquid mixture corresponding to the status of mean flow field. Numerical results of cavitating water jet issuing from an orifice nozzle are presented and its applicability to intensively cavitating jets is demonstrated. However, the effect of impact pressure caused by collapsing of bubbles is neglected, and effectively coupling of the present compressible mixture flow method with the dynamics of bubbles remains to be a challenge.
文摘A supercomputer with 1.0 Petaflops peak performance in single precision, designed and established by Institute of Process Engineering, Chinese Academy of Sciences, is introduced in this brief communication. A designing philosophy utilizing the similarity between hardware, software and the problems to be solved is embodied, based on the multi-scale method and discrete simulation approaches developed at Institute of Process Engineering （IPE） and implemented in a graphic processing unit （GPU）-based hybrid computing mode. The preliminary applications of this machine in areas of multi-phase flow, molecular dynamics and so on are reported, demonstrating the supercomputer as a paradigm of green computation in new architecture.
