isoAdvector是一种新的几何VOF(Volume of Fluid)方法,虽然克服了传统几何VOF方法难以适用于三维空间任意多面体网格的缺点,但不能直接用来模拟涉及动网格技术的液舱晃荡.为此,引入了运动通量修正,并提出了面-界面交线运动修正,使得修...isoAdvector是一种新的几何VOF(Volume of Fluid)方法,虽然克服了传统几何VOF方法难以适用于三维空间任意多面体网格的缺点,但不能直接用来模拟涉及动网格技术的液舱晃荡.为此,引入了运动通量修正,并提出了面-界面交线运动修正,使得修正后的isoAdvector方法可以应用到液舱晃荡的模拟中.基于不同的VOF方法对非共振、共振受迫晃荡和单次冲击波面进行数值模拟,并将模拟结果与试验结果以及解析解进行了比较.结果表明:相对于代数VOF方法,采用修正后的isoAdvector方法获得的自由液面位置和整体水动力载荷精度更高;捕捉的波面没有褶皱,能够较好地模拟波面的翻卷和破碎.此外,提出了界面厚度的估计方法,分析了自由液面波高精度提高的原因.展开更多
We investigate a novel spatial geometric phase of hybrid-polarized vector fields consisting of linear, elliptical and circular polarizations by Young＇s two-slit interferometer instead of the widely used Mach-Zehnder ...We investigate a novel spatial geometric phase of hybrid-polarized vector fields consisting of linear, elliptical and circular polarizations by Young＇s two-slit interferometer instead of the widely used Mach-Zehnder interferometer. This spatial geometric phase can be manipulated by engineering the spatial configuration of hybrid polarizations, and is directly related to the topological charge, the local states of polarization and the rotational symmetry of hybrid-polarized vector optical fields. The unique feature of geometric phase has implications in quantum information science as well as other physical systems such as electron vortex beams.展开更多
In this study we characterized and investigated the specific phenomenon of "companion drops" in the drop-ondemand(DOD) ink jetting process.A series of simulations based on a piezoelectric DOD printhead syste...In this study we characterized and investigated the specific phenomenon of "companion drops" in the drop-ondemand(DOD) ink jetting process.A series of simulations based on a piezoelectric DOD printhead system is presented,adapting the volume-of-fluid(VOF) interface-capturing method to track the boundary evolution and model the interfacial physics.The results illustrate the causality between the generation of companion drops and droplet deviation behavior,as well as their close correlations with ink jetting straightness and printing accuracy.The characteristics of companion drops are summarized and compared with those of satellite drops.Also,a theoretical mechanism for the generation of companion drops is presented,and their effects and behaviors are analyzed and discussed.Finally,the effects of critical factors on the generation of companion drops are investigated and characterized based on variations in the printable pressure range.Recommendations are given for the suppression of companion drops and for the improvement of printing accuracy.展开更多
文摘isoAdvector是一种新的几何VOF(Volume of Fluid)方法,虽然克服了传统几何VOF方法难以适用于三维空间任意多面体网格的缺点,但不能直接用来模拟涉及动网格技术的液舱晃荡.为此,引入了运动通量修正,并提出了面-界面交线运动修正,使得修正后的isoAdvector方法可以应用到液舱晃荡的模拟中.基于不同的VOF方法对非共振、共振受迫晃荡和单次冲击波面进行数值模拟,并将模拟结果与试验结果以及解析解进行了比较.结果表明:相对于代数VOF方法,采用修正后的isoAdvector方法获得的自由液面位置和整体水动力载荷精度更高;捕捉的波面没有褶皱,能够较好地模拟波面的翻卷和破碎.此外,提出了界面厚度的估计方法,分析了自由液面波高精度提高的原因.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11534006,11674184 and 11374166the Natural Science Foundation of Tianjin under Grant No 16JC2DJC31300Collaborative Innovation Center of Extreme Optics
文摘We investigate a novel spatial geometric phase of hybrid-polarized vector fields consisting of linear, elliptical and circular polarizations by Young＇s two-slit interferometer instead of the widely used Mach-Zehnder interferometer. This spatial geometric phase can be manipulated by engineering the spatial configuration of hybrid polarizations, and is directly related to the topological charge, the local states of polarization and the rotational symmetry of hybrid-polarized vector optical fields. The unique feature of geometric phase has implications in quantum information science as well as other physical systems such as electron vortex beams.
基金Project supported by the National Key Technology R&D Program(No. 2011BAD01B03)the Key Project of Science and Technology Program of Zhejiang Province (No. 2009C11099)the Zhejiang Provincial Natural Science Foundation (No. Y1110230)
文摘In this study we characterized and investigated the specific phenomenon of "companion drops" in the drop-ondemand(DOD) ink jetting process.A series of simulations based on a piezoelectric DOD printhead system is presented,adapting the volume-of-fluid(VOF) interface-capturing method to track the boundary evolution and model the interfacial physics.The results illustrate the causality between the generation of companion drops and droplet deviation behavior,as well as their close correlations with ink jetting straightness and printing accuracy.The characteristics of companion drops are summarized and compared with those of satellite drops.Also,a theoretical mechanism for the generation of companion drops is presented,and their effects and behaviors are analyzed and discussed.Finally,the effects of critical factors on the generation of companion drops are investigated and characterized based on variations in the printable pressure range.Recommendations are given for the suppression of companion drops and for the improvement of printing accuracy.
