排序方式: 共有171条查询结果,搜索用时 15 毫秒
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海冰动力学数值模拟中改进的PIC方法 总被引:2,自引:0,他引:2
为了准确地模拟海冰的动力过程,需要建立精确有效的数值方法。本文结合质点网格法(PIC)和光滑质点流体动力学方法(SPH)发展了一种改进的PIC方法。该方法在欧拉坐标下对海冰动量方程进行差分计算,在拉格朗日坐标下进行海冰质点位移、厚度和密集度计算,并采用Gauss函数进行欧拉网格点与拉格朗日质点间海冰参数的交互插值。采用改进的PIC方法对规则区域内的海冰堆积过程进行了数值试验,对渤海海冰的动力过程进行了72小时数值模拟。计算结果均表明改进的PIC方法具有计算量小,计算结果平稳精确的优点,可很好地适用于海冰动力作用过程的数值模拟。 相似文献
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Particle-in-Cell/Monte Carlo Collision simulation of planar DC magnetron sputtering 总被引:2,自引:0,他引:2
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In this paper a numerical simulation of a planar DC magnetron discharge is performed with the Particle-in Cell/Monte Carlo Collision (PIC/MCC) method. The magnetic field used in the simulation is calculated with finite element method according to experimental configuration. The simulation is carried out under the condition of gas pressure of 0.665 Pa and voltage magnitude of 400V. Typical results such as the potential distribution, charged particle densities, the discharge current density and ion flux onto the target are calculated. The erosion profile from the simulation is compared with the experimental data. The maximum erosion position corresponds to the place where the magnetic field lines are parallel to the target surface. 相似文献
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提出了一种新结构的高功率径向强流速调管振荡器,该器件利用折叠式同轴谐振腔的微波场与接近空间电荷限制电流的径向电子束强烈相互作用产生高功率微波。首先对这种器件的实现机理进行了初步的分析,提出了有间隙电压情况时的径向同轴间隙的空间电荷限制电流1维近似估计模型。分析表明:对于电子束直流接近但小于直流空间限制电流的径向速调管,当有调制间隙电压时,空间限制电流要小于无调制间隙电压情况下的直流空间限制电流,径向强流电子束电流接近和超过空间电荷限制电流时会出现强烈的调制。然后用PIC程序对其特性进行了粒子模拟,在二极管输入电压500 kV、电子束电流为30 kA条件下,最终得到了峰值功率6 GW、频率1.3 GHz的微波输出。 相似文献
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Baoqing Zeng Chongfeng Yang Zhonghai Yang Shangjie Qian 《International Journal of Infrared and Millimeter Waves》2003,24(10):1767-1775
Using the particle-in-cell (PIC) simulation code MAGIC, the wedge emitter, parallel gate and anode with and without co-planar lens have been simulated. The electron beam streamlines and the X-Vx phase space have been evaluated, which show that the co-planar lens focuses the electron. Simulation results are presented for a single FEA's cell with the anode biased at 500V and spaced 100m from the cathode, which indicated that the electron beam width at anode is about 60.2m for without lens FEAs, after add the lens with –70V, the electron beam width will be decrease to 8.1m, meanwhile the maximum transverse velocity will decrease from ±1×106m/s to ±1.46×105m/s. 相似文献
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We propose a novel ultra compact structure of micro-disks embedded microring filter (MDEMR) and several parameters which impact the performance of MDEMR are analyzed. The filter is shown to exhibit much smaller size and better spectrum than traditional microring one. The number and radius of the inner disks are found to mainly influence the resonance frequency of the micro-disks, and the valley of transmittivity. The resonance between microring and micro-disks is decrease with increasing the gap between microring and micro-disks, which also leads to the extinction ratio improved significantly. The Q factor is found to be improved from 300 to 3000 with the gap increased from 0.2 μm to 0.4 μm, while the transmission peak affected slightly. 相似文献
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H. Timko K. Ness Sjobak L. Mether S. Calatroni F. Djurabekova K. Matyash K. Nordlund R. Schneider W. Wuensch 《等离子体物理论文集》2015,55(4):299-314
Understanding plasma initiation in vacuum arc discharges can help to bridge the gap between nano‐scale triggering phenomena and the macroscopic surface damage caused by vacuum arcs. We present a new twodimensional particle‐in‐cell tool to simulate plasma initiation in direct‐current (DC) copper vacuum arc discharges starting from a single, strong field emitter at the cathode. Our simulations describe in detail how a sub‐micron field emission site can evolve to a macroscopic vacuum arc discharge, and provide a possible explanation for why and how cathode spots can spread on the cathode surface. Furthermore, the model provides us with a prediction for the current and voltage characteristics, as well as for properties of the plasma like densities, fluxes and electric potentials in a simple DC discharge case, which are in agreement with the known experimental values. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Jung-Hwan Hong Kum-Young Song Hyun-Ju Chung Jong-Han Jung Whi-Young Kim Uk Kang Hee-Je Kim 《Optics & Laser Technology》2002,34(3):203-207
In this study, a solid-state laser system adopting a new real time multi-discharge method in which three flashlamps are turned on consecutively was designed and fabricated to examine the pulse width and the pulse shape of the laser beams depending upon the changes in the lamp turn-on time. That is, this study shows a technology that makes it possible to make various pulse shapes by turning on three flashlamps consecutively on a real-time basis with the aid of a program integrated circuit one-chip microprocessor. With this technique, the lamp turn-on delay time can be varied more diversely from 0 to 10 ms and the real-time control is possible with an external keyboard, enabling various pulse shapes. In addition, longer pulses can be more widely used for industrial processing and many medical purposes. 相似文献
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针对准中性Vlasov-Poisson系统中多尺度物理参数共存的问题开展研究,采用渐近保持格式推导出与Vlasov方程相耦合的Poisson方程。数值模拟了一维等离子体在真空中的膨胀,比较了渐近保持PIC算法与传统PIC算法模拟结果的异同。结果表明:两种算法在满足多尺度中小尺度量限制的前提下,其结果保持高度一致;且在克服小尺度量束缚时,渐近保持PIC算法依然可以正确地模拟等离子体的物理行为,大大节省了计算时间。 相似文献