Energy dissipation by whistler turbulence: Three-dimensional particle-in-cell simulations

2014 ◽  
Vol 21 (5) ◽  
pp. 052305 ◽  
Author(s):  
Ouliang Chang ◽  
S. Peter Gary ◽  
Joseph Wang
Keyword(s):  
Energy Dissipation ◽  
Three Dimensional ◽  
Particle In Cell

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.

scholarly journals NEW EVIDENCE OF DISCRETE SCALE INVARIANCE IN THE ENERGY DISSIPATION OF THREE-DIMENSIONAL TURBULENCE: CORRELATION APPROACH AND DIRECT SPECTRAL DETECTION

2003 ◽  
Vol 14 (04) ◽  
pp. 459-470 ◽  
Author(s):  
WEI-XING ZHOU ◽  
DIDIER SORNETTE ◽  
VLADILEN PISARENKO
Keyword(s):  
Energy Dissipation ◽  
Three Dimensional ◽  
Energy Dissipation Rate ◽  
Corrections To Scaling ◽  
Developed Turbulence ◽  
Pairwise Correlations ◽  
Spectral Detection ◽  
Simple Variant ◽  
High Reynolds ◽  
New Evidence

We extend the analysis of Ref. 16 showing statistically significant log-periodic corrections to scaling in the moments of the energy dissipation rate in experiments at high Reynolds number (≈ 2500) of three-dimensional fully developed turbulence. First, we develop a simple variant of the canonical averaging method using a rephasing scheme between different samples based on pairwise correlations that confirms Zhou and Sornette's previous results. The second analysis uses a simpler local spectral approach and then performs averages over many local spectra. This yields stronger evidence of the existence of underlying log-periodic undulations, with the detection of more than 20 harmonics of a fundamental logarithmic frequency f = 1.434 ± 0.007 corresponding to the preferred scaling ratio γ = 2.008 ± 0.006.

Three-Dimensional Analysis of Closed-Die Forging Processes: Part 1: Formulation

1989 ◽  
Vol 203 (1) ◽  
pp. 33-37 ◽  
Author(s):  
C F Lugora ◽  
A N Bramley
Keyword(s):  
Theoretical Model ◽  
Energy Dissipation ◽  
Metal Flow ◽  
Three Dimensional ◽  
Total Rate ◽  
Die Forging ◽  
Closed Die Forging ◽  
Proposed Model ◽  
Optimum Velocity ◽  
Forging Load

In this series of papers, a theoretical model based on the upper bound elemental technique is presented for prediction of forging load and metal flow in three-dimensional closed-die forging processes. Three basic elements are introduced in order to partition a forging into simple elementary regions. An optimum velocity distribution within the forging is obtained by minimizing the total rate of energy dissipation using a simplex optimizing procedure. Applications of the proposed model are discussed in Part 2.

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