scholarly journals Global Three‐Dimensional Simulation of Earth's Dayside Reconnection Using a Two‐Way Coupled Magnetohydrodynamics With Embedded Particle‐in‐Cell Model: Initial Results

2017 ◽  
Vol 122 (10) ◽  
pp. 10,318-10,335 ◽  
Author(s):  
Yuxi Chen ◽  
Gábor Tóth ◽  
Paul Cassak ◽  
Xianzhe Jia ◽  
Tamas I. Gombosi ◽  
...  
Keyword(s):  
Cell Model ◽  
Three Dimensional ◽  
Particle In Cell ◽  
Dimensional Simulation ◽  
Initial Results

Post-solitons and electron vortices generated by femtosecond intense laser interacting with uniform near-critical-density plasmas

2021 ◽  
Author(s):  
Dong-Ning Yue ◽  
Min Chen ◽  
Yao Zhao ◽  
Pan-Fei Geng ◽  
Xiao-Hui Yuan ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Critical Density ◽  
Laser Pulses ◽  
Intense Laser ◽  
Nonlinear Structures ◽  
Particle In Cell ◽  
Laser Propagation ◽  
Laser Driver ◽  
Linearly Polarized ◽  
Dimensional Simulation

Abstract Generation of nonlinear structures, such as stimulated Raman side scattering waves, post-solitons and electron vortices, during ultra-short intense laser pulse transportation in near-critical-density (NCD) plasmas are studied by using multi-dimensional particle-in-cell (PIC) simulations. In two-dimensional geometries, both P- and S- polarized laser pulses are used to drive these nonlinear structures and to check the polarization effects on them. In the S-polarized case, the scattered waves can be captured by surrounding plasmas leading to the generation of post-solitons, while the main pulse excites convective electric currents leading to the formation of electron vortices through Kelvin-Helmholtz instability (KHI). In the P-polarized case, the scattered waves dissipate their energy by heating surrounding plasmas. Electron vortices are excited due to the hosing instability of the drive laser. These polarization dependent physical processes are reproduced in two different planes perpendicular to the laser propagation direction in three-dimensional simulation with linearly polarized laser driver. The current work provides inspiration for future experiments of laser-NCD plasma interactions.

Three Dimensional Simulation of the Heat Dissipation of an Automotive Radiator Based on Porous Media Method

2014 ◽  
Vol 543-547 ◽  
pp. 207-210
Author(s):  
Ning Kang ◽  
Ni Ka Mo ◽  
Wei Qi Zheng
Keyword(s):  
Porous Media ◽  
Least Squares ◽  
Heat Dissipation ◽  
Least Squares Method ◽  
Cell Model ◽  
Three Dimensional ◽  
Cell Models ◽  
Air Inlet ◽  
Dimensional Simulation ◽  
Porous Media Method

12 kinds of automotive radiator cell models were simulated at different air inlet velocities using CFD software Fluent. The distributed drag coefficients of each cell model were obtained by least squares method. Then the whole radiator model whose fins region was replaced by the porous media was simulated. The numerical results were validated by experiments which indicate that the porous media method is reliable. The study shows that the radiator heat dissipation is significantly influenced by fin structure and the model with a fin space of 1.4mm and a louver angle of 23o has the best cooling effect.

scholarly journals On the Analytical Solution of the Kuwabara-Type Particle-in-Cell Model for the Non-Axisymmetric Spheroidal Stokes Flow via the Papkovich–Neuber Representation

Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 170
Author(s):  
Panayiotis Vafeas ◽  
Eleftherios Protopapas ◽  
Maria Hadjinicolaou
Keyword(s):  
Stokes Flow ◽  
Cell Model ◽  
Flow Behavior ◽  
Mathematical Formulation ◽  
Three Dimensional ◽  
Flow Fields ◽  
Particle In Cell ◽  
Embedded Particles ◽  
Type Particle ◽  
Spheroidal Geometry

Modern engineering technology often involves the physical application of heat and mass transfer. These processes are associated with the creeping motion of a relatively homogeneous swarm of small particles, where the spheroidal geometry represents the shape of the embedded particles within such aggregates. Here, the steady Stokes flow of an incompressible, viscous fluid through an assemblage of particles, at low Reynolds numbers, is studied by employing a particle-in-cell model. The mathematical formulation adopts the Kuwabara-type assumption, according to which each spheroidal particle is stationary and it is surrounded by a confocal spheroid that creates a fluid envelope, in which the Newtonian fluid moves with a constant velocity of arbitrary orientation. The boundary value problem in the fluid envelope is solved by imposing non-slip conditions on the surface of the spheroid, which is also considered as non-penetrable, while zero vorticity is assumed on the fictitious spheroidal boundary along with a uniform approaching velocity. The three-dimensional flow fields are calculated analytically for the first time, in the spheroidal geometry, by virtue of the Papkovich–Neuber representation. Through this, the velocity and the total pressure fields are provided in terms of a vector and the scalar spheroidal harmonic potentials, which enables the thorough study of the relevant physical characteristics of the flow fields. The newly obtained analytical expressions generalize to any direction with the existing results holding for the asymmetrical case, which were obtained with the aid of a stream function. These can be employed for the calculation of quantities of physical or engineering interest. Numerical implementation reveals the flow behavior within the fluid envelope for different geometrical cell characteristics and for the arbitrarily-assumed velocity field, thus reflecting the different flow/porous media situations. Sample calculations show the excellent agreement of the obtained results with those available for special geometrical cases. All of these findings demonstrate the usefulness of the proposed method and the powerfulness of the obtained analytical expansions.

scholarly journals Development of a Gyrokinetic Particle-in-Cell Code for Whole-Volume Modeling of Stellarators

Plasma ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 179-200 ◽  
Author(s):  
Toseo Moritaka ◽  
Robert Hager ◽  
Michael Cole ◽  
Samuel Lazerson ◽  
Choong-Seock Chang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Three Dimensional ◽  
Zonal Flow ◽  
Field Calculation ◽  
Edge Region ◽  
Particle In Cell ◽  
Benchmark Tests ◽  
Volume Modeling ◽  
Field Lines ◽  
Initial Results

We present initial results in the development of a gyrokinetic particle-in-cell code for the whole-volume modeling of stellarators. This is achieved through two modifications to the X-point Gyrokinetic Code (XGC), originally developed for tokamaks. One is an extension to three-dimensional geometries with an interface to Variational Moments Equilibrium Code (VMEC) data. The other is a connection between core and edge regions that have quite different field-line structures. The VMEC equilibrium is smoothly extended to the edge region by using a virtual casing method. Non-axisymmetric triangular meshes in which triangle nodes follow magnetic field lines in the toroidal direction are generated for field calculation using a finite-element method in the entire region of the extended VMEC equilibrium. These schemes are validated by basic benchmark tests relevant to each part of the calculation cycle, that is, particle push, particle-mesh interpolation, and field solver in a magnetic field equilibrium of Large Helical Device including the edge region. The developed code also demonstrates collisionless damping of geodesic acoustic modes and steady states with residual zonal flow in the core region.

Three-Dimensional Simulation of Rarefied Plasma Flows Using a High Order Particle in Cell Method

2011 ◽  
pp. 593-604 ◽  
Author(s):  
J. Neudorfer ◽  
T. Stindl ◽  
A. Stock ◽  
R. Schneider ◽  
D. Petkow ◽  
...  
Keyword(s):  
Three Dimensional ◽  
High Order ◽  
Plasma Flows ◽  
Particle In Cell ◽  
Cell Method ◽  
Dimensional Simulation

Three-dimensional particle-in-cell model of Hall thruster: The discharge channel

2018 ◽  
Vol 25 (6) ◽  
pp. 061208 ◽  
Author(s):  
Francesco Taccogna ◽  
Pierpaolo Minelli
Keyword(s):  
Discharge Channel ◽  
Cell Model ◽  
Three Dimensional ◽  
Hall Thruster ◽  
Particle In Cell
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