共查询到16条相似文献,搜索用时 427 毫秒
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用量子Maxwell-BlochC-数方程讨论了存在均匀消相阻尼的一维稀薄等离子体系统中电场和极化的发展过程及相干特性,给出了线性阶段的解析结果和非线性阶段的数值结果。数值结果显示了电场和极化的发展过程及随机源对它们的影响。最后给出了电场和极化的相干度及自由电子对相干度的影响。当等离子体频率远小于辐射频率时,自由电子的作用可以忽略。 相似文献
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基于Schwarz-Christoffel变换的平板电容器电场电荷分布仿真 总被引:1,自引:0,他引:1
本文利用施瓦兹-克里斯多菲(S-C)变换,得出并讨论了计及边缘效应的平行板电容器的电场、电荷分布函数.利用离散化与数值迭代的方法,通过Matlab数值仿真得出了其电场和电荷分布的较精确的可视化结果. 相似文献
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胆甾相液晶电控螺旋畸变导致的布拉格反射特性 总被引:4,自引:0,他引:4
研究了平面织构胆甾相液晶在垂直于螺旋轴方向施加电场后,引起螺旋畸变导致布拉格反射光强度变化特性,利用液晶矩阵光学,琼斯矩阵法与Matlab矩阵计算软件对有螺旋畸变情况下的布拉格反射光谱特性进行了分析和数值计算.从数值计算和实验结果可知,胆甾相液晶在其垂直螺旋轴方向施加不同电压电场时,布拉格反射光中心波长不随电压改变,而布拉格反射光强会随电压的增大而减弱.提出一种电致螺旋畸变模型,对实验结果和数值计算结果给出了合理的解释,认为利用电场改变胆甾相液晶螺距进而设计电控颜色变化液晶器件的原理是不可靠的. 相似文献
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沙尘暴和尘卷风等风沙运动的静电场是空气流场中沙粒间的碰撞摩擦带电及沙粒粒径的分层效应引起的, 本文耦合沙粒摩擦荷电模型和风沙运动气固两相流模型, 提出了离散单元法与计算流体动力学结合的数值方法. 数值模拟计算表明电荷呈中性的沙粒临界直径为300 μm; 在充分发展的水平风沙流中, 细小的沙粒带负电, 较大直径的沙粒带正电, 所模拟的沙粒带电的荷质比及水平风洞试验段的电场强度与实验测量值一致, 验证了风沙运动的电场-流场耦合模型及数值计算方法的合理性. 本文基于沙粒摩擦荷电机理的风沙运动气固两相流模型提供了理解风沙运动静电场产生的一种物理机理. 相似文献
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In this study, based on different numberical simulation methods, the gas-liquid two-phase flow is taken as the research object. By coupling the continuity equation of incompressible fluid, Navier-Stokes equation, electric field equation and other control equations, a multi-field coupling model for rising bubbles in viscous fluids is established, and numerical simulations are carried out. The two-phase popularity of coupled electric field is studied, and the effect of electric field on bubble motion is analyzed.The Level-set and phase field method are used to track the changes of deformation and rupture during the rising of the bubble. The accuracy and validity of the two methods are verified by mass conservation. At the same time, the calculation area is determined for the accuracy of calculation, and the optimal mesh size is calculated by using mesh independence test. Compared with the level set method, the phase field method has a certain improvement in the calculation efficiency and accuracy. Among them, the calculation efficiency of the phase field calculation method in the same grid is increased by 5 times, and by 3 times in the vertical electric field environment. Moreover, using the phase field method is easier to capture the bubbles slight changes while they are rising, and the quality of the simulation results is better.The simulation analysis of bubble rising process under coupled electric field by two methods shows that under the interaction of electrostatic force, buoyancy and surface tension, the bubble is stretched into an ellipsoid along the direction of the electric field line, and the ratio of the length to the short axis is proportional to the applied electric field strength. In addition, the bubble rising velocity is affected by the electric field, and the vertical electric field accelerates the rising of the bubble. 相似文献
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建立了直流电场作用下协流式微流控装置中单乳液液滴乳化生成过程的非稳态理论模型,并开展了数值模拟研究,揭示了电场对液滴乳化生成动力学行为的调控机理,阐明了流场/电场参数对液滴乳化生成特性的影响规律.研究结果表明:沿流体流动方向施加静电场可在电物性参数不同的两相流体界面法线方向上产生指向内相流体的电场力,进而强化了内相流体界面的颈缩和断裂,提升了液滴生成速率和形变程度,减小了液滴生成尺寸;在同一毛细数下,随着电毛细数的增大,乳液乳化流型由每周期仅有单一液滴生成的滴式流型转变为每周期有一个主液滴并伴随有卫星液滴生成的滴式流型;随着毛细数和电毛细数的增大,黏性拖曳力以及电场力作用增强,使内相流体颈缩过程后期更容易形成细长型液线,从而有助于诱发液线上产生Rayleigh-Plateau不稳定现象,继而促进卫星液滴的形成. 相似文献
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In this study, the behavior of a single bubble in a dielectric viscous fluid under a uniform magnetic field has been simulated numerically using the Level Set method in two-phase bubbly flow. The two-phase bubbly flow was considered to be laminar and homogeneous. Deformation of the bubble was considered to be due to buoyancy and magnetic forces induced from the external applied magnetic field. A computer code was developed to solve the problem using the flow field, the interface of two phases, and the magnetic field. The Finite Volume method was applied using the SIMPLE algorithm to discretize the governing equations. Using this algorithm enables us to calculate the pressure parameter, which has been eliminated by previous researchers because of the complexity of the two-phase flow. The finite difference method was used to solve the magnetic field equation. The results outlined in the present study agree well with the existing experimental data and numerical results. These results show that the magnetic field affects and controls the shape, size, velocity, and location of the bubble. 相似文献