The field-circuit coupled physical simulation of open boundary electric field

2021 ◽  
Author(s):  
Li Zhang ◽  
Qing Chen ◽  
Hongbin Li ◽  
Zemin Qu
Keyword(s):  
Electric Field ◽  
Physical Simulation ◽  
Open Boundary

scholarly journals Time Domain Modelling of First Return Stroke of Lightning

2008 ◽  
Vol 2 (1) ◽  
pp. 261-270 ◽  
Author(s):  
Udaya Kumar ◽  
Rosy B. Raysaha ◽  
K.P. Dileep Kumar
Keyword(s):  
Electric Field ◽  
Field Evaluation ◽  
Simulation Method ◽  
Static Field ◽  
Linear Increase ◽  
Cloud Base ◽  
Open Boundary ◽  
Lightning Flash ◽  
Return Stroke ◽  
Stroke Evolution

The four most important factors that govern the return stroke evolution can be identified as: (i) electric field due to charge distributed along the channel, (ii) transient enhancement of conductance by several orders at the bridging regime (iii) the non-linear increase in channel conductance at the propagating current front and (iv) the associated dynamic electromagnetic field which support the evolution of current along the channel. For a more realistic modelling of the lightning return stroke, the present work attempts to consider these aspects in suitable manner. The charge simulation method is employed for evaluating the quasi-static field due to (i). For the dynamic field, the problem involves conduction along a thin structure with open boundary on one side. Further, in order to efficiently represent a vertically extended grounded strike object, as well as, channel of quite arbitrary geometry, boundary based approach is believed to be the ideal choice. Considering these, a time-dependent electric field integral equation (TD-EFIE) along with a sub-sectional collocation form of the method of moments (MoM) is chosen for the numerical field evaluation. The dynamic variation of conductance in the channel other than the bridging zone is modelled by a first order arc equation. For the bridging zone, arc equation which explicitly portray in some sense, accumulation of energy is considered. Accordingly, formulations given by Barannik, Popovic and Toepler were scrutinized for their suitability. After some preliminary simulation studies, a self contained model for the first return stoke of a lightning flash is presented. The stability of the model is verified by running the program for longer durations with different cloud base potentials and cloud base heights. Simulation results are in agreement with the field data on current and velocity decay rate for the first one kilometer height. Also, the relation between the charge density at channel tip and the return stroke current peak favorably compares with the literature.

scholarly journals Phase-space holes due to electron and ion beams accelerated by a current-driven potential ramp

2003 ◽  
Vol 10 (1/2) ◽  
pp. 37-44 ◽  
Author(s):  
M. V. Goldman ◽  
D. L. Newman ◽  
R. E. Ergun
Keyword(s):  
Phase Space ◽  
Electric Field ◽  
Double Layer ◽  
Ion Beams ◽  
Double Layers ◽  
Open Boundary ◽  
Neutral Density ◽  
One Dimensional ◽  
Slow Moving ◽  
A Current

Abstract. One-dimensional open-boundary simulations have been carried out in a current-carrying plasma seeded with a neutral density depression and with no initial electric field. These simulations show the development of a variety of nonlinear localized electric field structures: double layers (unipolar localized fields), fast electron phase-space holes (bipolar fields) moving in the direction of electrons accelerated by the double layer and trains of slow alternating electron and ion phase-space holes (wave-like fields) moving in the direction of ions accelerated by the double layer. The principal new result in this paper is to show by means of a linear stability analysis that the slow-moving trains of electron and ion holes are likely to be the result of saturation via trapping of a kinetic-Buneman instability driven by the interaction of accelerated ions with unaccelerated electrons.

Effect and Optimization Study of Composite Insulator Sheds Radius on Electric Filed Distribution

2015 ◽  
Vol 738-739 ◽  
pp. 159-163 ◽  
Author(s):  
Hong Xia Miao ◽  
Ben Sheng Qi ◽  
Chang Chun Cai
Keyword(s):  
Electric Field ◽  
Optimal Solution ◽  
Parameter Analysis ◽  
Open Boundary ◽  
The Finite Element Method ◽  
Composite Insulator ◽  
Field Range ◽  
Optimization Study ◽  
Electric Filed ◽  
Field Element

A method to optimize the structure parameters of sheds has been put forward for transmission line composite insulator. Fist of all, the unbounded domain is simulated by far field element to handle the open boundary problem of the insulator electric field model. Then, the finite element method (FEM) is employed to calculate the electrical field. The influence of sheds radius on composite insulator electric filed distribution is analyzed. The sheds radius is selected as optimization variable, and the optimization objective is to make the electric field more uniform. Moreover, the parameter analysis method is employed, and the optimal solution of the sheds radius is obtained. The optimized sheds radius make the electric field range and gradient along the insulator surface both tend to the minimum.

scholarly journals Electric Field Induced Electrorotation of 2D Perovskite Microplates

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1228
Author(s):  
Ruifu Zhou ◽  
Daobiao Hong ◽  
Siyu Gao ◽  
Yu Gu ◽  
Xuhai Liu
Keyword(s):  
Electrical Conductivity ◽  
Electric Field ◽  
External Electric Field ◽  
High Speed ◽  
Electric Field Distribution ◽  
Physical Simulation ◽  
Electrode System ◽  
Maximum Speed ◽  
Two Dimensional ◽  
Ac Electric Field

High precision-controlled movement of microscale devices is crucial to obtain advanced miniaturized motors. In this work, we report a high-speed rotating micromotor based on two-dimensional (2D) all-inorganic perovskite CsPbBr3 microplates controlled via alternating-current (AC) external electric field. Firstly, the device configuration with optimized electric field distribution has been determined via systematic physical simulation. Using this optimized biasing configuration, when an AC electric field is applied at the four-electrode system, the microplates suspended in the tetradecane solution rotate at a speed inversely proportional to AC frequency, with a maximum speed of 16.4 × 2π rad/s. Furthermore, the electrical conductivity of CsPbBr3 microplates has been determined in a contactless manner, which is approximately 10−9–10−8 S/m. Our work has extended the investigations on AC electric field-controlled micromotors from 1D to 2D scale, shedding new light on developing micromotors with new configuration.

Resolution in photoelectron microscopy

1991 ◽  
Vol 49 ◽  
pp. 458-459
Author(s):  
G. F. Rempfer
Keyword(s):  
Electron Microscopy ◽  
Electric Field ◽  
Ultraviolet Light ◽  
Uniform Field ◽  
Virtual Image ◽  
Lens System ◽  
Photoemission Electron Microscopy ◽  
Planar Electrode ◽  
Electron Lens ◽  
Photoemission Electron

In photoelectron microscopy (PEM), also called photoemission electron microscopy (PEEM), the image is formed by electrons which have been liberated from the specimen by ultraviolet light. The electrons are accelerated by an electric field before being imaged by an electron lens system. The specimen is supported on a planar electrode (or the electrode itself may be the specimen), and the accelerating field is applied between the specimen, which serves as the cathode, and an anode. The accelerating field is essentially uniform except for microfields near the surface of the specimen and a diverging field near the anode aperture. The uniform field forms a virtual image of the specimen (virtual specimen) at unit lateral magnification, approximately twice as far from the anode as is the specimen. The diverging field at the anode aperture in turn forms a virtual image of the virtual specimen at magnification 2/3, at a distance from the anode of 4/3 the specimen distance. This demagnified virtual image is the object for the objective stage of the lens system.

Field-assisted ionization theory for microscopists

1994 ◽  
Vol 52 ◽  
pp. 820-821
Author(s):  
Patrick P. Camus
Keyword(s):  
Electric Field ◽  
Electron Tunneling ◽  
Ionization Probability ◽  
Critical Distance ◽  
Tunneling Probability ◽  
Field Ionization ◽  
Radius Of Curvature ◽  
Field Evaporation ◽  
A Value ◽  
Ion Emission

The theory of field ion emission is the study of electron tunneling probability enhanced by the application of a high electric field. At subnanometer distances and kilovolt potentials, the probability of tunneling of electrons increases markedly. Field ionization of gas atoms produce atomic resolution images of the surface of the specimen, while field evaporation of surface atoms sections the specimen. Details of emission theory may be found in monographs.Field ionization (FI) is the phenomena whereby an electric field assists in the ionization of gas atoms via tunneling. The tunneling probability is a maximum at a critical distance above the surface,xc, Fig. 1. Energy is required to ionize the gas atom at xc, I, but at a value reduced by the appliedelectric field, xcFe, while energy is recovered by placing the electron in the specimen, φ. The highest ionization probability occurs for those regions on the specimen that have the highest local electric field. Those atoms which protrude from the average surfacehave the smallest radius of curvature, the highest field and therefore produce the highest ionizationprobability and brightest spots on the imaging screen, Fig. 2. This technique is called field ion microscopy (FIM).

Sign in / Sign up

Export Citation Format

Share Document