In this paper, vortex-induced vibrations of a cylinder are simulated by use of ANSYS CFX simulation code. The cylinder is treated as a rigid body and transverse displacements are obtained by use of a one degree of fre...In this paper, vortex-induced vibrations of a cylinder are simulated by use of ANSYS CFX simulation code. The cylinder is treated as a rigid body and transverse displacements are obtained by use of a one degree of freedom spring damper system. 2-D as well as 3-D analysis is performed using air as the fluid. Reynolds number is varied from 40 to 16000 approx., covering the laminar and turbulent regimes of flow. The experimental results of （Khalak and Williamson, 1997） and other researchers are used for validation purposes. The results obtained are comparable.展开更多
Current numerical models of gas metal arc welding（GMAW）are trying to combine magnetohydrodynamics （MRD） models of the arc and voiume of fluid （VoF） models of metal transfer They neglect vaporization and assume a...Current numerical models of gas metal arc welding（GMAW）are trying to combine magnetohydrodynamics （MRD） models of the arc and voiume of fluid （VoF） models of metal transfer They neglect vaporization and assume an argon atmosphere for the arc region, as it is common practice for models of gas tungsten arc welding, These models predict temperatures above 20 000K anda temperature distribution similar to tungsten inert gas （TIG） arcs： However. current spectroscopic temperature measuretemperatures. In contrast to TIG arcs temperature distrbution. The paper vapour and which is in a yery good res, Futhermore; the model is abile to predict the local central minimum in the radial temperature and the radial electric current density distributions for the first time. The axially symmetric model of the welding torch, the work piece, the wire and the arc （fluid domain） implements MHD as well as turbulent mixing and thermal demixing of metal vapour in argon. The mass fraction of iron vapour obtained from the simulation shows an accumulation in the arc core and another accumulation on the fringes of the arc at 2000 to 5000 K. The demixing effects lead to very low concentrations of iron between these two regions. Sensitive analyses demonstrate the influence of the transport and radiation properties of metal vapour, and the evaporation rate relative to the wire feed. Finally the model predictions are compared with the measuring results of Zielihska et al.展开更多
A new integrated oil production enhancement technology based on water-flooding energy recovery is proposed.After providing an extensive review of the existing scientific and technical literature on this subject,the pr...A new integrated oil production enhancement technology based on water-flooding energy recovery is proposed.After providing an extensive review of the existing scientific and technical literature on this subject,the proposed integrated technology is described together with the related process flow diagram,the criteria used to select a tar-get facility for its implementation and the outcomes of the laboratory studies conducted to analyze emulsion formation and separation kinetics.Moreover,the outcomes of numerical simulations performed using Ansys CFX software are also presented.According to these results,using the proposed approach the incremental oil production may reach 1.2 t/day(with a 13%increase)and more,even at low flow rates(less than 10 t/day),thereby providing evidence for the benefits associated with this integrated technology.展开更多
文摘In this paper, vortex-induced vibrations of a cylinder are simulated by use of ANSYS CFX simulation code. The cylinder is treated as a rigid body and transverse displacements are obtained by use of a one degree of freedom spring damper system. 2-D as well as 3-D analysis is performed using air as the fluid. Reynolds number is varied from 40 to 16000 approx., covering the laminar and turbulent regimes of flow. The experimental results of （Khalak and Williamson, 1997） and other researchers are used for validation purposes. The results obtained are comparable.
文摘Current numerical models of gas metal arc welding（GMAW）are trying to combine magnetohydrodynamics （MRD） models of the arc and voiume of fluid （VoF） models of metal transfer They neglect vaporization and assume an argon atmosphere for the arc region, as it is common practice for models of gas tungsten arc welding, These models predict temperatures above 20 000K anda temperature distribution similar to tungsten inert gas （TIG） arcs： However. current spectroscopic temperature measuretemperatures. In contrast to TIG arcs temperature distrbution. The paper vapour and which is in a yery good res, Futhermore; the model is abile to predict the local central minimum in the radial temperature and the radial electric current density distributions for the first time. The axially symmetric model of the welding torch, the work piece, the wire and the arc （fluid domain） implements MHD as well as turbulent mixing and thermal demixing of metal vapour in argon. The mass fraction of iron vapour obtained from the simulation shows an accumulation in the arc core and another accumulation on the fringes of the arc at 2000 to 5000 K. The demixing effects lead to very low concentrations of iron between these two regions. Sensitive analyses demonstrate the influence of the transport and radiation properties of metal vapour, and the evaporation rate relative to the wire feed. Finally the model predictions are compared with the measuring results of Zielihska et al.
基金supported by the Government of Perm Krai,Research Project No.С-26/510。
文摘A new integrated oil production enhancement technology based on water-flooding energy recovery is proposed.After providing an extensive review of the existing scientific and technical literature on this subject,the proposed integrated technology is described together with the related process flow diagram,the criteria used to select a tar-get facility for its implementation and the outcomes of the laboratory studies conducted to analyze emulsion formation and separation kinetics.Moreover,the outcomes of numerical simulations performed using Ansys CFX software are also presented.According to these results,using the proposed approach the incremental oil production may reach 1.2 t/day(with a 13%increase)and more,even at low flow rates(less than 10 t/day),thereby providing evidence for the benefits associated with this integrated technology.
