During the manufacturing or processing of materials,large volumes of water of the required quality are often needed.Industrial water treatment and water purification is the process of removing impurities and pollution...During the manufacturing or processing of materials,large volumes of water of the required quality are often needed.Industrial water treatment and water purification is the process of removing impurities and pollution from the considered medium.To obtain liquid with specified quality parameters,complex systems of filters and treatment facilities are generally used.In this work,the cleaning process for a filtration column is studied.Three-dimensional numerical simulations of flow in a columnar array consisting of a porous medium are conducted.In particular,a model case corresponding to laboratory conditions is examined,with potassium salt being considered as a pollutant.It is assumed that the vertical column is a desalination system,as a result of which saturation and clogging of the pores of the medium occur;at the end of the operating cycle of such a filter,washing is required.Filtration modeling is implemented through the Brinkman approach taking into account density stratification.It is found that owing to density stratification and related effects,clean water moves in the central part of the filter,while contaminants near the side walls remain motionless for a long time.A solution to this problem is presented by changing the flow rate of supplied water.展开更多
The study deals with the numerical modeling of leachate distribution in the porous medium located under a municipal solid waste disposal landfill(MSWLF).The considered three-layer system is based on geological data ob...The study deals with the numerical modeling of leachate distribution in the porous medium located under a municipal solid waste disposal landfill(MSWLF).The considered three-layer system is based on geological data obtained from field measurements.For simplicity,the problem is investigated by assuming a two-component approach.Nevertheless,the heat produced by landfills due to biological and chemical processes and the thermal diffusion mechanism contributing to pollution transport are taken into account.The numerical modeling of the propagation of leachate in the considered layered porous medium is implemented for parameters corresponding to natural soil and for the case where disruption of the porous medium structure is due to cracks formation or erosion.The latter is accompanied by an increase in rock permeability.In this case,the emergence of multi-vortex flow in the layer of high permeability is observed to substantially influence the bottom layers and cause intensification of the leachate propagation.These effects should be taken into account when estimating the parameters and properties of materials required for the construction of solid waste disposal facilities.展开更多
External vibrations are known to be one of the promising ways to control the behavior of multiphase systems. Thecomputational modeling of the behavior of a gas bubble in a viscous liquid in a horizontal cylinder of sq...External vibrations are known to be one of the promising ways to control the behavior of multiphase systems. Thecomputational modeling of the behavior of a gas bubble in a viscous liquid in a horizontal cylinder of squarecross-section, which undergoes linearly polarized translational oscillations in weightless conditions, has been carried out. Under vibrations, the bubble moves towards the wall of the vessel with acceleration determined by theamplitudes and frequency of vibrations. Near the wall, at a distance of the order of the thickness of the viscousStokes boundary layer, the effects of viscosity become more important and, as a result, the bubble is repelled fromthe wall. After some oscillations, equilibrium conditions are attained where the attractive force balances the repulsive force;accordingly, the average position of the bubble ceases to change. The numerical modelling shows thatthe average behaviors of a deformable bubble near a wall under normal and tangential vibration are similar.展开更多
基金supported by a grant from the Russian Science Foundation(Project No.20-11-20125).
文摘During the manufacturing or processing of materials,large volumes of water of the required quality are often needed.Industrial water treatment and water purification is the process of removing impurities and pollution from the considered medium.To obtain liquid with specified quality parameters,complex systems of filters and treatment facilities are generally used.In this work,the cleaning process for a filtration column is studied.Three-dimensional numerical simulations of flow in a columnar array consisting of a porous medium are conducted.In particular,a model case corresponding to laboratory conditions is examined,with potassium salt being considered as a pollutant.It is assumed that the vertical column is a desalination system,as a result of which saturation and clogging of the pores of the medium occur;at the end of the operating cycle of such a filter,washing is required.Filtration modeling is implemented through the Brinkman approach taking into account density stratification.It is found that owing to density stratification and related effects,clean water moves in the central part of the filter,while contaminants near the side walls remain motionless for a long time.A solution to this problem is presented by changing the flow rate of supplied water.
文摘The study deals with the numerical modeling of leachate distribution in the porous medium located under a municipal solid waste disposal landfill(MSWLF).The considered three-layer system is based on geological data obtained from field measurements.For simplicity,the problem is investigated by assuming a two-component approach.Nevertheless,the heat produced by landfills due to biological and chemical processes and the thermal diffusion mechanism contributing to pollution transport are taken into account.The numerical modeling of the propagation of leachate in the considered layered porous medium is implemented for parameters corresponding to natural soil and for the case where disruption of the porous medium structure is due to cracks formation or erosion.The latter is accompanied by an increase in rock permeability.In this case,the emergence of multi-vortex flow in the layer of high permeability is observed to substantially influence the bottom layers and cause intensification of the leachate propagation.These effects should be taken into account when estimating the parameters and properties of materials required for the construction of solid waste disposal facilities.
基金supported by the Ministry of Science and High Education of Russia(Theme No.121031700169-1).
文摘External vibrations are known to be one of the promising ways to control the behavior of multiphase systems. Thecomputational modeling of the behavior of a gas bubble in a viscous liquid in a horizontal cylinder of squarecross-section, which undergoes linearly polarized translational oscillations in weightless conditions, has been carried out. Under vibrations, the bubble moves towards the wall of the vessel with acceleration determined by theamplitudes and frequency of vibrations. Near the wall, at a distance of the order of the thickness of the viscousStokes boundary layer, the effects of viscosity become more important and, as a result, the bubble is repelled fromthe wall. After some oscillations, equilibrium conditions are attained where the attractive force balances the repulsive force;accordingly, the average position of the bubble ceases to change. The numerical modelling shows thatthe average behaviors of a deformable bubble near a wall under normal and tangential vibration are similar.
