This paper presents a hybrid finite volume/finite element method for the incompressible generalized Newtonian fluid flow （Power-Law model）. The collocated （i.e. non-staggered） arrangement of variables is used on t...This paper presents a hybrid finite volume/finite element method for the incompressible generalized Newtonian fluid flow （Power-Law model）. The collocated （i.e. non-staggered） arrangement of variables is used on the unstructured triangular grids, and a fractional step projection method is applied for the velocity-pressure coupling. The cell-centered finite volume method is employed to discretize the momentum equation and the vertex-based finite element for the pressure Poisson equation. The momentum interpolation method is used to suppress unphysical pressure wiggles. Numerical experiments demonstrate that the current hybrid scheme has second order accuracy in both space and time. Results on flows in the lid-driven cavity and between parallel walls for Newtonian and Power-Law models are also in good agreement with the published solutions.展开更多
The numerical modeling of oil displacement by nanofluid based on three-dimensional micromodel of cores with different permeability was carried out by the volume of fluid(VOF)method with experimentally measured values ...The numerical modeling of oil displacement by nanofluid based on three-dimensional micromodel of cores with different permeability was carried out by the volume of fluid(VOF)method with experimentally measured values of interfacial tension,contact angle and viscosity.Water-based suspensions of SiO_(2) nanoparticles with a concentration of 0–1%and different particle sizes were considered to study the effect of concentration and size of nanoparticles,displacement fluid flow rate,oil viscosity and core permeability on the efficiency of oil displacement by nanofluid.The oil recovery factor(ORF)increases with the increase of mass fraction of nanoparticles.An increase in nanoparticles’concentration to 0.5% allows an increase in ORF by about 19% compared to water flooding.The ORF increases with the decrease of nanoparticle size,and declines with the increase of displacing rate.It has been shown that the use of nanosuspensions for enhanced oil recovery is most effective for low-permeable reservoirs with highly viscous oil in injection modes with capillary number close to the immobilization threshold,and the magnitude of oil recovery enhancement decreases with the increase of displacement speed.The higher the oil viscosity,the lower the reservoir rock permeability,the higher the ORF improved by nanofluids will be.展开更多
Gas–liquid two-phase jets exhibit markedly enhanced impact performance due to the violent collapse of entrained bubbles,which generates transient microjets and shock waves.The geometry of the nozzle is a decisive fac...Gas–liquid two-phase jets exhibit markedly enhanced impact performance due to the violent collapse of entrained bubbles,which generates transient microjets and shock waves.The geometry of the nozzle is a decisive factor in controlling jet formation,flow modulation,and impact efficiency.In this work,the structural optimization of gas–liquid two-phase nozzles was investigated numerically using the Volume of Fluid(VOF).Simulation results show that the aero-shaped nozzle delivers a significantly stronger impact on the target surface than conventional geometries.Specifically,its impact pressure is 21%higher than that of a conical straight nozzle and 37%higher than that of a conical nozzle.The aero nozzle not only increases peak impact pressure but also sustains it over a longer duration,leading to an overall improvement in energy transfer efficiency.Parametric analyses further reveal the key geometric conditions governing performance.When the nozzle curvature is set to 0.01,the jet achieves a higher and more stable surface pressure profile,maintaining elevated impact for a prolonged period.At an aspect ratio of 15,the jet exhibits pronounced pulsation under high pressure,thereby enhancing impact intensity.The contraction ratio exerts a non-monotonic influence:as it increases,impact pressure initially rises and subsequently declines,with an optimal value of 4 yielding the highest and most persistent impact pressure.Likewise,when the ratio of inlet length to outlet diameter is 2.5,the jet demonstrates the strongest impact on the target surface.展开更多
In the present study, a three-dimensional computational fluid dynamics simulation together with experimental field measurements was applied to optimize the performance of an industrial hydrocyclone at Sarcheshmeh copp...In the present study, a three-dimensional computational fluid dynamics simulation together with experimental field measurements was applied to optimize the performance of an industrial hydrocyclone at Sarcheshmeh copper complex. In the simulation, the Eulerian–Eulerian approach was used for solid and liquid phases, the latter being water. In this approach, nine continuous phases were considered for the solid particles with different sizes and one continuous phase for water. The continuity and momentum equations with inclusion of buoyancy and drag forces were solved by the finite volume method. The k–e RNG turbulence model was used for modeling of turbulency. There was a good agreement between the simulation results and the experimental data. After validation of the model accuracy, the effect of inlet solid percentage, pulp inlet velocity, rod inserting in the middle of the hydrocyclone and apex diameter on hydrocyclone performance was investigated. The results showed that by decreasing the inlet solid percentage and increasing the pulp inlet velocity, the efficiency of hydrocyclone increased. Decreasing the apex diameter caused an increase in the hydrocyclone efficiency.展开更多
基金supported by the National Natural Science Foundation of China (10771134).
文摘This paper presents a hybrid finite volume/finite element method for the incompressible generalized Newtonian fluid flow （Power-Law model）. The collocated （i.e. non-staggered） arrangement of variables is used on the unstructured triangular grids, and a fractional step projection method is applied for the velocity-pressure coupling. The cell-centered finite volume method is employed to discretize the momentum equation and the vertex-based finite element for the pressure Poisson equation. The momentum interpolation method is used to suppress unphysical pressure wiggles. Numerical experiments demonstrate that the current hybrid scheme has second order accuracy in both space and time. Results on flows in the lid-driven cavity and between parallel walls for Newtonian and Power-Law models are also in good agreement with the published solutions.
文摘The numerical modeling of oil displacement by nanofluid based on three-dimensional micromodel of cores with different permeability was carried out by the volume of fluid(VOF)method with experimentally measured values of interfacial tension,contact angle and viscosity.Water-based suspensions of SiO_(2) nanoparticles with a concentration of 0–1%and different particle sizes were considered to study the effect of concentration and size of nanoparticles,displacement fluid flow rate,oil viscosity and core permeability on the efficiency of oil displacement by nanofluid.The oil recovery factor(ORF)increases with the increase of mass fraction of nanoparticles.An increase in nanoparticles’concentration to 0.5% allows an increase in ORF by about 19% compared to water flooding.The ORF increases with the decrease of nanoparticle size,and declines with the increase of displacing rate.It has been shown that the use of nanosuspensions for enhanced oil recovery is most effective for low-permeable reservoirs with highly viscous oil in injection modes with capillary number close to the immobilization threshold,and the magnitude of oil recovery enhancement decreases with the increase of displacement speed.The higher the oil viscosity,the lower the reservoir rock permeability,the higher the ORF improved by nanofluids will be.
基金funded by the National Natural Science Foundation of China,grant number 52204022Natural Science Foundation of Shandong Province,grant number ZR2022ME152+3 种基金Youth Innovation and Technology Support Program for Shandong Provincial Universities,grant number 2022KJ066National Key Research and Development Program of China,grant number 2021YFE0111400Shandong Provincial Key Research and Development Program(2025TSGCCZZB0419)The Major Special Project for Scientific and Technological Innovation of Dongying City(Science and Technology Development Guidance Plan),grant number 2023ZDJH110.
文摘Gas–liquid two-phase jets exhibit markedly enhanced impact performance due to the violent collapse of entrained bubbles,which generates transient microjets and shock waves.The geometry of the nozzle is a decisive factor in controlling jet formation,flow modulation,and impact efficiency.In this work,the structural optimization of gas–liquid two-phase nozzles was investigated numerically using the Volume of Fluid(VOF).Simulation results show that the aero-shaped nozzle delivers a significantly stronger impact on the target surface than conventional geometries.Specifically,its impact pressure is 21%higher than that of a conical straight nozzle and 37%higher than that of a conical nozzle.The aero nozzle not only increases peak impact pressure but also sustains it over a longer duration,leading to an overall improvement in energy transfer efficiency.Parametric analyses further reveal the key geometric conditions governing performance.When the nozzle curvature is set to 0.01,the jet achieves a higher and more stable surface pressure profile,maintaining elevated impact for a prolonged period.At an aspect ratio of 15,the jet exhibits pronounced pulsation under high pressure,thereby enhancing impact intensity.The contraction ratio exerts a non-monotonic influence:as it increases,impact pressure initially rises and subsequently declines,with an optimal value of 4 yielding the highest and most persistent impact pressure.Likewise,when the ratio of inlet length to outlet diameter is 2.5,the jet demonstrates the strongest impact on the target surface.
文摘In the present study, a three-dimensional computational fluid dynamics simulation together with experimental field measurements was applied to optimize the performance of an industrial hydrocyclone at Sarcheshmeh copper complex. In the simulation, the Eulerian–Eulerian approach was used for solid and liquid phases, the latter being water. In this approach, nine continuous phases were considered for the solid particles with different sizes and one continuous phase for water. The continuity and momentum equations with inclusion of buoyancy and drag forces were solved by the finite volume method. The k–e RNG turbulence model was used for modeling of turbulency. There was a good agreement between the simulation results and the experimental data. After validation of the model accuracy, the effect of inlet solid percentage, pulp inlet velocity, rod inserting in the middle of the hydrocyclone and apex diameter on hydrocyclone performance was investigated. The results showed that by decreasing the inlet solid percentage and increasing the pulp inlet velocity, the efficiency of hydrocyclone increased. Decreasing the apex diameter caused an increase in the hydrocyclone efficiency.
