In this paper,multi_quadric equations interpolation is used to establish a widely covered and valuable speed field model,with which the crustal movement image is obtained.
During high-speed gas metal arc welding （GMAW）, the backward flowing molten jet with high momentum in the weld pool is considered to be responsible for the occurrence of humping bead. To suppress humping bead, an el...During high-speed gas metal arc welding （GMAW）, the backward flowing molten jet with high momentum in the weld pool is considered to be responsible for the occurrence of humping bead. To suppress humping bead, an electromagnetic device is developed and coupled with the welding system. By adjusting the conditions of external magnetic field, forward electromagnetic force is obtained to reduce the momentum of the backward flow of molten metal in weld pool. Consequently, the humping bead can be suppressed by adjusting the external magnetic field. Bead-on-plate welding experiment was conducted on mild steel plates, and the influence of magnetic flux density on the arc deflection angle and weld bead quality is investigated. It is found that external magnetic field can remarkably adjust the momentum of backward flow jet and significantly improve the quality of weld bead.展开更多
A series of experimental results of field-reversed configurations(FRCs) on a KMAX(Keda Mirror with AXisymmetricity) tandem mirror machine are reported.Single-side FRC translation processes with three different gas spe...A series of experimental results of field-reversed configurations(FRCs) on a KMAX(Keda Mirror with AXisymmetricity) tandem mirror machine are reported.Single-side FRC translation processes with three different gas species were measured by avalanche photodiodes.Consistent with the theoretical prediction, the measured FRC speeds were inversely proportional to the square root of the ion mass.However, the speeds of the hydrogen FRC increased even in a uniform magnetic field region while the speeds of the helium and argon FRCs decreased.Possible mechanisms are discussed.The speed of the second pass due to the reflection of the mirror fields was found to be ~1/3 of the first pass speed.The internal magnetic fields were measured for a colliding-merging argon FRC, and the results show that, even for very slowmoving FRCs, merging can occur.展开更多
Based on incompressible viscous fluid Navier-stokes equation and k-ε 2-equations turbulent model, an investigation on 3D turbulent flow field around four kinds of train models has been made by finite element method. ...Based on incompressible viscous fluid Navier-stokes equation and k-ε 2-equations turbulent model, an investigation on 3D turbulent flow field around four kinds of train models has been made by finite element method. From the calculation, the pressure distribution characters of now field around high-speed trains have been obtained. It is significant for strength design of the high-speed train body, for resisting wind design of the facilities beside the high-speed railways and for determining the aerodynamic force of induced air to the human body near the railways.展开更多
文摘In this paper,multi_quadric equations interpolation is used to establish a widely covered and valuable speed field model,with which the crustal movement image is obtained.
基金The authors are grateful to the financial support for this research from the National Natural Science Foundation of China，the Research Fund for the Doctoral Program of Higher Education of China
文摘During high-speed gas metal arc welding （GMAW）, the backward flowing molten jet with high momentum in the weld pool is considered to be responsible for the occurrence of humping bead. To suppress humping bead, an electromagnetic device is developed and coupled with the welding system. By adjusting the conditions of external magnetic field, forward electromagnetic force is obtained to reduce the momentum of the backward flow of molten metal in weld pool. Consequently, the humping bead can be suppressed by adjusting the external magnetic field. Bead-on-plate welding experiment was conducted on mild steel plates, and the influence of magnetic flux density on the arc deflection angle and weld bead quality is investigated. It is found that external magnetic field can remarkably adjust the momentum of backward flow jet and significantly improve the quality of weld bead.
基金supported by the National Key R&D Program of China (Nos.2017YFA0402500 and 2017YFE0301802)National Natural Science Foundation (No.11475172)the Key Research Program of Frontier Sciences, CAS (No.QYZDJ-SSW-DQC010)
文摘A series of experimental results of field-reversed configurations(FRCs) on a KMAX(Keda Mirror with AXisymmetricity) tandem mirror machine are reported.Single-side FRC translation processes with three different gas species were measured by avalanche photodiodes.Consistent with the theoretical prediction, the measured FRC speeds were inversely proportional to the square root of the ion mass.However, the speeds of the hydrogen FRC increased even in a uniform magnetic field region while the speeds of the helium and argon FRCs decreased.Possible mechanisms are discussed.The speed of the second pass due to the reflection of the mirror fields was found to be ~1/3 of the first pass speed.The internal magnetic fields were measured for a colliding-merging argon FRC, and the results show that, even for very slowmoving FRCs, merging can occur.
文摘Based on incompressible viscous fluid Navier-stokes equation and k-ε 2-equations turbulent model, an investigation on 3D turbulent flow field around four kinds of train models has been made by finite element method. From the calculation, the pressure distribution characters of now field around high-speed trains have been obtained. It is significant for strength design of the high-speed train body, for resisting wind design of the facilities beside the high-speed railways and for determining the aerodynamic force of induced air to the human body near the railways.
