The flow of the weak electrolyte solution can be controlled by Lorentz force achieved with the suitable magnetic and electric fields, and it has the advantages of vortex street suppression, drag reduction, lift enhanc...The flow of the weak electrolyte solution can be controlled by Lorentz force achieved with the suitable magnetic and electric fields, and it has the advantages of vortex street suppression, drag reduction, lift enhancement and oscillatory suppression for the flow over a bluff body. The electro-magnetic control of vortex-induced vibration (VIV) of a circular cylinder in the shear flow was investigated numerically in the exponential-polar coordinates attached on the moving cylinder for Re=150. With the effect of background vorticity, the vortex street of VIV cylinder was composed of two parallel rows with an opposite sign of the vortices which inclines toward the lower side and the strength of upper vortex is larger than that of lower vortex. The lift force vibrated periodically with the effect of vortex shedding and the mean value was negative due to the background vorticity. The Lorentz force for controlling the VIV cylinder was classified into the field Lorentz force and the wall Lorentz force. The field Lorentz force suppresses the lift oscillation, and in turn, suppresses the VIV, whereas the wall Lorentz force increases the lift.展开更多
Stabilizing the interface wave of the molten aluminum(metal)-electrolyte(bath)is beneficial to shorten the anode-cathode distance(ACD)which is critical to the energy saving.A coupled mathematical model was developed t...Stabilizing the interface wave of the molten aluminum(metal)-electrolyte(bath)is beneficial to shorten the anode-cathode distance(ACD)which is critical to the energy saving.A coupled mathematical model was developed to study the impact of the novel cathode protrusion on the molten fluid motion as well as the metal-bath interface deformation.The molten fluid motion in the aluminum reduction ceils is under the combined effect of the electro-magnetic forces(EMFs)and the gas bubbles generated at the anode.A transient inhomogeneous three-phase model(metal-bath-gas bubble)was established in order to calculate more accurate.The results indicate that the metal-bath interface deformation can be reduced significantly by the novel cathode protrusion which is beneficial to the electric energy saving.Besides,The EMFs decreases as a result of the optimizing of the magnetic field due to the novel cathode convex which is an important driving force for the deformation of the interface.In addition,large vortex in the metal flow field is break up into the small vortex by the cathode protrusion and then dissipated due to the viscous force and the hindering effect of the cathode protrusion.The quantity of the vortex as well as the strength of the vortex reduces significantly in the reduction cell with novel cathode protrusion.展开更多
基金Sponsored by the National Nature Science Foundation of China (11202102,11172140)
文摘The flow of the weak electrolyte solution can be controlled by Lorentz force achieved with the suitable magnetic and electric fields, and it has the advantages of vortex street suppression, drag reduction, lift enhancement and oscillatory suppression for the flow over a bluff body. The electro-magnetic control of vortex-induced vibration (VIV) of a circular cylinder in the shear flow was investigated numerically in the exponential-polar coordinates attached on the moving cylinder for Re=150. With the effect of background vorticity, the vortex street of VIV cylinder was composed of two parallel rows with an opposite sign of the vortices which inclines toward the lower side and the strength of upper vortex is larger than that of lower vortex. The lift force vibrated periodically with the effect of vortex shedding and the mean value was negative due to the background vorticity. The Lorentz force for controlling the VIV cylinder was classified into the field Lorentz force and the wall Lorentz force. The field Lorentz force suppresses the lift oscillation, and in turn, suppresses the VIV, whereas the wall Lorentz force increases the lift.
基金Item Sponsored by the National Natural Science Foundation of China[NO.50934005 and NO.50904014]
文摘Stabilizing the interface wave of the molten aluminum(metal)-electrolyte(bath)is beneficial to shorten the anode-cathode distance(ACD)which is critical to the energy saving.A coupled mathematical model was developed to study the impact of the novel cathode protrusion on the molten fluid motion as well as the metal-bath interface deformation.The molten fluid motion in the aluminum reduction ceils is under the combined effect of the electro-magnetic forces(EMFs)and the gas bubbles generated at the anode.A transient inhomogeneous three-phase model(metal-bath-gas bubble)was established in order to calculate more accurate.The results indicate that the metal-bath interface deformation can be reduced significantly by the novel cathode protrusion which is beneficial to the electric energy saving.Besides,The EMFs decreases as a result of the optimizing of the magnetic field due to the novel cathode convex which is an important driving force for the deformation of the interface.In addition,large vortex in the metal flow field is break up into the small vortex by the cathode protrusion and then dissipated due to the viscous force and the hindering effect of the cathode protrusion.The quantity of the vortex as well as the strength of the vortex reduces significantly in the reduction cell with novel cathode protrusion.
基金Item Sponsored by the Oriented Fundamental Research Program of UB RAS (project No 11-1-03-AVI) under the agreement between the ICMM UB RAS and Berezniki JSC AVISMA Ltd Companythe project of the International Research Group"Magnetohydrodynamic stirring of liquid metal and its influence on a solidified alloy structure"
文摘The paper describes MHD-methods for creating a pumping effect in metallurgical installations for pumping liquid metals.
