Dual-mode of topological rainbow in gradual photonic heterostructures

2021 ◽  
Author(s):  
Mingxing Li ◽  
Yueke Wang ◽  
Mengjia Lu ◽  
Tian Sang
Keyword(s):  
Finite Element Method ◽  
Finite Element Method Simulation ◽  
Two Dimensional ◽  
Edge States ◽  
Dual Mode ◽  
Strong Robustness ◽  
Mode Excitation ◽  
Simulation Results ◽  
Photonic States ◽  
Sandwiched Structure

Abstract In this letter, a method to realize the topological rainbow trapping is presented, which is composed of gradual ordinary-topological-ordinary heterostructures based on two-dimensional photonic crystals with C-4 symmetry. In the proposed sandwiched structure, the two coupled topological edge states with different frequencies are separated and trapped in different positions, due to group velocity of near to zero. We have achieved the dual-mode of topological rainbow in one structure, which broadens the bandwidth. Besides, the dual-mode of topological rainbow under one mode excitation is also realized by using a simple bend design. The immunity to defects is also investigated and it is found our slowing light system has strong robustness. Finite Element Method simulation results verify our idea, and our work opens up a new way for frequency routing and broadband operation of topological photonic states.

scholarly journals Small Caliber Bulletproof Test of Warships’ Hulls

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3848
Author(s):  
Radosław Kiciński ◽  
Andrzej Kubit
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Boundary Conditions ◽  
Finite Element Method Simulation ◽  
Material Model ◽  
Experimental Results ◽  
Material Constants ◽  
Steel Core ◽  
Calculation Results ◽  
Simulation Results

The article presents the characteristics of 1.3964 steel and the results of firing a 7.62 mm projectile with a steel core. A simplified Johnson–Cook material model for steel and projectile was used. Then, a FEM (finite element method) simulation was prepared to calibrate the material constants and boundary conditions necessary to be used in simulations of the entire hull model. It was checked how projectile modeling affects the FEM calculation results. After obtaining the simulation results consistent with the experimental results, using the model of a modern minehunter, the resistance of the ship’s hull to penetration by a small-caliber projectile was tested.

Minimization of X-Ray Mask Distortion by Two-Dimensional Finite Element Method Simulation

1990 ◽  
Vol 29 (Part 1, No. 10) ◽  
pp. 2203-2206 ◽  
Author(s):  
Akihiko Kishimoto ◽  
Shinji Kuniyoshi ◽  
Naoto Saito ◽  
Takashi Soga ◽  
Kozo Mochiji ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Method Simulation ◽  
Two Dimensional ◽  
X Ray ◽  
Dimensional Finite Element ◽  
Element Method

scholarly journals Modeling and Analysis of the Two-Dimensional Axisymmetric Acoustofluidic Fields in the Probe-Type and Substrate-Type Ultrasonic Micro/Nano Manipulation Systems

Micromachines ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 22
Author(s):  
Pengzhan Liu ◽  
Qiang Tang ◽  
Songfei Su ◽  
Jie Hu ◽  
Yang Yu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Working Conditions ◽  
Probe Type ◽  
Two Dimensional ◽  
The Finite Element Method ◽  
Substrate Type ◽  
Modeling And Analysis ◽  
Physical Mechanisms ◽  
Simulation Results

The probe-type and substrate-type ultrasonic micro/nano manipulation systems have proven to be two kinds of powerful tools for manipulating micro/nanoscale materials. Numerical simulations of acoustofluidic fields in these two kinds of systems can not only be used to explain and analyze the physical mechanisms of experimental phenomena, but also provide guidelines for optimization of device parameters and working conditions. However, in-depth quantitative study and analysis of acoustofluidic fields in the two ultrasonic micro/nano manipulation systems have scarcely been reported. In this paper, based on the finite element method (FEM), we numerically investigated the two-dimensional (2D) axisymmetric acoustofluidic fields in the probe-type and substrate-type ultrasonic micro/nano manipulation systems by the perturbation method (PM) and Reynolds stress method (RSM), respectively. Through comparing the simulation results computed by the two methods and the experimental verifications, the feasibility and reasonability of the two methods in simulating the acoustofluidic fields in these two ultrasonic micro/nano manipulation systems have been validated. Moreover, the effects of device parameters and working conditions on the acoustofluidic fields are clarified by the simulation results and qualitatively verified by the experiments.

Analysis of Leakage Current on 11kV Zinc Oxide Surge Arrester Using Finite Element Method

2015 ◽  
Vol 785 ◽  
pp. 348-352 ◽  
Author(s):  
Nurul Ain Abdul Latiff ◽  
Hazlee Azil Illias ◽  
Ab Halim Abu Bakar
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Leakage Current ◽  
Comsol Multiphysics ◽  
Two Dimensional ◽  
Surge Arresters ◽  
Housing Materials ◽  
Simulation Results ◽  
Degree Of Degradation ◽  
Element Method

Leakage current is known to be directly related to the degree of degradation of arrester. Leakage current is commonly flow across arrester under non-conducting condition. In this work, a two-dimensional (2D) axial-symmetrical 11kV surge arrester model was developed and used to simulate the leakage current under normal condition. The influence of insulator shed widths, housing materials and sizes of ZnO in an 11kV ZnO surge arrester design on its leakage current was studied using finite element method (FEM) software, which is COMSOL Multiphysics. The simulation results show that leakage current is mostly affected by the sizes of the ZnO and material of the housing. From this work, an understanding on the leakage current behaviors in a ZnO surge arrester can be enhanced. This study may also help in improving the design of surge arresters in reducing leakage current.

A simplified numerical and analytical study for assessing the seismic response of a gravity concrete lock

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Neander Berto Mendes ◽  
Lineu José Pedroso ◽  
Paulo Marcelo Vieira Ribeiro
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Analytical Study ◽  
Two Dimensional ◽  
The Finite Element Method ◽  
Fluid Structure ◽  
Analytical Formulation ◽  
Acoustic Cavity ◽  
Water Chamber ◽  
Structure Problem

ABSTRACT: This work presents the dynamic response of a lock subjected to the horizontal S0E component of the El Centro earthquake for empty and completely filled water chamber cases, by coupled fluid-structure analysis. Initially, the lock was studied by approximation, considering it similar to the case of a double piston coupled to a two-dimensional acoustic cavity (tank), representing a simplified analytical model of the fluid-structure problem. This analytical formulation can be compared with numerical results, in order to qualify the responses of the ultimate problem to be investigated. In all the analyses performed, modeling and numerical simulations were done using the finite element method (FEM), supported by the commercial software ANSYS.

scholarly journals New Sensor for Medium- and High-Voltage Measurement

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4654
Author(s):  
Andrzej Wetula ◽  
Andrzej Bień ◽  
Mrunal Parekh
Keyword(s):  
Finite Element Method ◽  
Electronic Devices ◽  
Finite Element Method Simulation ◽  
Laboratory Model ◽  
Power Electronic ◽  
Proof Of Concept ◽  
Voltage Measurement ◽  
Medium Voltage ◽  
Narrow Frequency Band ◽  
Further Development

Measurements of medium and high voltages in a power grid are normally performed with large and bulky voltage transformers or capacitive dividers. Besides installation problems, these devices operate in a relatively narrow frequency band, which limits their usability in modern systems that are saturated with power electronic devices. A sensor that can be installed directly on a wire and can operate without a galvanic connection to the ground may be used as an alternative voltage measurement device. This type of voltage sensor can complement current sensors installed on a wire, forming a complete power acquisition system. This paper presents such a sensor. Our sensor is built using two dielectric elements with different permeability coefficients. A finite element method simulation is used to estimate the parameters of a constructed sensor. Besides simulations, a laboratory model of a sensor was built and tested in a medium-voltage substation. Our results provide a proof of concept for the presented sensor. Some errors in voltage reconstruction have been traced to an oversimplified data acquisition and transmission system, which has to be improved during the further development of the sensor.

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