Wire-medium loaded planar structures: modal analysis, near fields, and radiation features

2016 ◽  
Vol 8 (4-5) ◽  
pp. 713-722 ◽  
Author(s):  
Davide Comite ◽  
Paolo Baccarelli ◽  
Paolo Burghignoli ◽  
Alessandro Galli
Keyword(s):  
Simulation Software ◽  
Planar Structures ◽  
Transverse Resonance ◽  
Tem Mode ◽  
Field Matching ◽  
Field Radiation ◽  
Vertically Aligned ◽  
Transverse Electromagnetic ◽  
Spurious Radiation

A novel transmission-line model is used for the analysis of planar structures, including wire-medium (WM) slabs with vertically aligned wires. The network formalism allows for an effective determination of the relevant spectral Green's functions, of the modal dispersion equation via transverse resonance, as well as of the far-field radiation pattern produced by simple sources via reciprocity, as opposed to the more cumbersome field-matching approach. Numerical results, validated also against state-of-the-art simulation software, confirm the accuracy and effectiveness of the proposed approach. In particular, modal and radiation features are presented for a class of leaky-wave antennas based on planar WM loaded configurations covered by partially reflecting screens, for which leaky unimodal regimes are achieved by minimizing spurious radiation from the quasi-transverse electromagnetic (TEM) mode.

Application of OLI Electrolyte Simulation to the Resolution of Corrosion Concerns Within a Reciprocating Compressor

2012 ◽  
Author(s):  
Diane L. Stewart ◽  
Anthony J. Gerbino ◽  
Tony Scribner
Keyword(s):  
Simulation Software ◽  
Dew Point ◽  
Reciprocating Compressor ◽  
Particulate Contamination ◽  
Ionic Equilibria ◽  
Water Ph ◽  
Condensed Water ◽  
Compressor Reliability

A 38 MMSCF/D Cooper Bessemer Model LM-9 reciprocating compressor in hydrogen service at the Praxair Westlake LA facility has experienced notable particulate contamination within the feed gas. The particulates were believed to be caused by upstream piping corrosion; however, to definitely state the cause, the properties of the fluid existing in the five-stage compressor needed to be more fully understood. An OLI electrochemical simulation software was used for dew point prediction, determination of the condensed phase ionic equilibria, and corrosion rate prediction. These tasks were beyond capabilities of the site-licensed UniSim software, as presently configured. Specifically, the model was used to identify the dew point conditions (temperature, pressure) and properties of the condensed water (pH, corrosivity, dissolved O2, and chlorine speciation). Model results were compared with site inspection findings. Subsequently, recommended limits for chlorine and oxygen in the feed gas were established to improve long term compressor reliability.

An Analytical Description of the Magnetic Conductance Across an Isolated Defect Region in a 1D-Ferromagnetic Lead

SPIN ◽  
2019 ◽  
Vol 09 (01) ◽  
pp. 1950005 ◽  
Author(s):  
Adel Belayadi ◽  
Boualem Bourahla ◽  
Ahmed Mougari
Keyword(s):  
Contact Region ◽  
Analytical Description ◽  
Quantum Scattering ◽  
Defect Region ◽  
Model Calculations ◽  
Adopted Model ◽  
Field Matching ◽  
Ferromagnetic Lead ◽  
Transmission And Reflection

We illustrate in this contribution the determination of the magnetic conductance across a nanocontact region defined by an isolated defect region joined between two mono-atomic leads ferromagnetically ordered. The system is described by the Heisenberg interaction. Additionally, to deal with the lack of symmetry across the contact region defined by the isolated defect, we involve the phase field matching approach. Furthermore, to compute the quantum conductance, we define the quantum scattering of the transmission and reflection probabilities within the framework of Landauer–Büttiker formalism. Based on these approaches, we present an analytical expression of the magnetic conductance. The obtained analytical results based on our adopted procedures confirm the known results adopted for perfect infinite leads (no defect). Our model calculations can be applied numerically when we deal with doping across the defect region. The adopted model could be also used numerically to deal with the impurity configurations that one might encounter in real systems.

scholarly journals Determination of Optimal Production Process Using Scheduling and Simulation Software

2018 ◽  
Vol 17 (4) ◽  
pp. 609-622 ◽  
Author(s):  
D. Duplakova ◽  
M. Teliskova ◽  
J. Duplak ◽  
J. Torok ◽  
M. Hatala ◽  
...  
Keyword(s):  
Production Process ◽  
Simulation Software ◽  
Optimal Production

Experimental and Numerical Study of the Cutting Temperature during the Turning of the C45 Steel

2016 ◽  
Vol 823 ◽  
pp. 507-512
Author(s):  
Mourad Abdelkrim ◽  
Mourad Brioua ◽  
Abderrahim Belloufi ◽  
Abdelhafid Gherfi
Keyword(s):  
Numerical Study ◽  
Digital Simulation ◽  
Cutting Temperature ◽  
Medium Carbon Steel ◽  
Simulation Software ◽  
Interface Temperature ◽  
Work Piece ◽  
Turning Process

In machining operation, the quality of surface finish is an important requirement for many turned work pieces. cutting temperature is one of the most important parameters in determining the cutting performance and tool life. the objective for this work is to estimate the cutting temperature in 3D model on tool-chip interface and the interface temperature during turning process, using the digital simulation software COMSOL Multiphysics.The tool–chip interface temperature results obtained from experimental results by using C45 medium carbon steel work piece with natural contact tools, without the application of cooling and lubricating agents and a K type thermocouple technique was used for estimating cutting temperatures in a turning operation.This procedure facilitates the determination of the temperature at tool-chip interface in dry turning process, which is still a challenge for existing experimental and numerical methods.

scholarly journals TEM modes influenced electron acceleration by Hermite–Gaussian laser beam in plasma

2016 ◽  
Vol 34 (3) ◽  
pp. 385-393 ◽  
Author(s):  
Harjit Singh Ghotra ◽  
Niti Kant
Keyword(s):  
Laser Beam ◽  
Beam Width ◽  
Electron Acceleration ◽  
Particle Simulation ◽  
Electron Interaction ◽  
Electron Dynamics ◽  
Gaussian Laser Beam ◽  
Trapping Force ◽  
Tem Mode ◽  
Transverse Electromagnetic

AbstractElectron acceleration by a circularly polarized Hermite–Gaussian (HG) laser beam in the plasma has been investigated theoretically for the different transverse electromagnetic (TEM) mode indices (m, n) as (0, 1), (0, 2), (0, 3), and (0, 4). HG laser beam possesses higher trapping force compared with a standard Gaussian beam owing to its propagation characteristics during laser–electron interaction. A single-particle simulation indicates a resonant enhancement in the electron acceleration with HG laser beam. We present the intensity distribution for different TEM modes. We also analyze the dependence of beam width parameter on electron acceleration distance, which effectively influences the electron dynamics. Electron acceleration up to longer distance is observed with the lower modes. However, the higher electron energy gain is observed with higher modes at shorter distance of propagation.

scholarly journals Far-Field Reconstruction from Transient Near-Field Measurement Using Cylindrical Modal Development

2009 ◽  
Vol 2009 ◽  
pp. 1-7 ◽  
Author(s):  
R. Rammal ◽  
M. Lalande ◽  
E. Martinod ◽  
N. Feix ◽  
M. Jouvet ◽  
...  
Keyword(s):  
Field Measurement ◽  
Near Field ◽  
Accurate Determination ◽  
Ultra Wideband ◽  
Far Field ◽  
Field Radiation ◽  
Measurement Base ◽  
Large Frequency ◽  
Near Field Measurement

The aim of this work is to get far field radiation patterns for any radiating source from transient acquisition, in a large frequency range. An outdoor transient Ultra-Wideband near-field measurement base will be installed, a single time pulse radiated by the source will cover the desired spectrum, and the accurate determination of far field radiations will be accomplished by means of cylindrical waves' modal development. This method uses simplified test equipments, easy to be installed, and it reduces measurement costs.

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