Results 71 to 80 of about 36,417 (233)

A fluid-dynamical subgrid scale model for highly compressible astrophysical turbulence [PDF]

Astronomy & Astrophysics, 2011
We formulate and implement the Euler equations with SGS dynamics and provide numerical tests of an SGS turbulence energy model that predicts the turbulent pressure of unresolved velocity fluctuations and the rate of dissipation for highly compressible turbulence.
Schmidt, W., Federrath, C. et al.
openaire   +4 more sources

Analytical and Numerical Soliton Solutions of the Shynaray II‐A Equation Using the G′G,1G$$ \left(\frac{G^{\prime }}{G},\frac{1}{G}\right) $$‐Expansion Method and Regularization‐Based Neural Networks

Mathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT Nonlinear differential equations play a fundamental role in modeling complex physical phenomena across solid‐state physics, hydrodynamics, plasma physics, nonlinear optics, and biological systems. This study focuses on the Shynaray II‐A equation, a relatively less‐explored parametric nonlinear partial differential equation that describes ...
Aamir Farooq, H. W. A. Riaz, Sadique Rehman, M. Mamun Miah, Wen Xiu Ma   +4 more
wiley   +1 more source

What can we say about seed fields for galactic dynamos?

, 2012
We demonstrate that a quasi-uniform cosmological seed field is a much less suitable seed for a galactic dynamo than has often been believed. The age of the Universe is insufficient for a conventional galactic dynamo to generate a contemporary galactic ...
Brandenburg A, David Moss, Dmitry Sokoloff, Moss D, Moss D, Neronov AV, Sokoloff D, Subramanian K, Sur S, Zeldovich YaB   +9 more
core   +2 more sources

Piecewise-Parabolic Methods for Astrophysical Fluid Dynamics [PDF]

, 1986
A general description of some modern numerical techniques for the simulation of astrophysical fluid flow is presented. The methods are introduced with a thorough discussion of the especially simple case of advection. Attention is focussed on the piecewise-parabolic method (PPM).
openaire   +1 more source

A Novel Optimized Local Linearization Hybrid Block Method for Chaotic Systems: Applications to Stretch‐Twist‐Fold Flow and Bond Orbital Chaotic Attractors

Mathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT The numerical approximation of nonlinear chaotic differential systems, such as the modified stretch‐twist‐fold (STF) flow and multi‐bond chaotic attractors, presents a significant challenge due to their sensitive dependence on initial conditions and complex dynamics where analytical solutions are unattainable.
Shina Daniel Oloniiju, Anastacia Dlamini
wiley   +1 more source

Topics in microphysics of relativistic plasmas

, 2013
Astrophysical plasmas can have parameters vastly different from the more studied laboratory and space plasmas. In particular, the magnetic fields can be the dominant component of the plasma, with energy-density exceeding the particle rest-mass energy ...
Lazarian, Alexandre, Lyutikov, Maxim
core   +1 more source

Linear Toroidal‐Inertial Waves on A Differentially Rotating Sphere with Application to Helioseismology: Modeling, Forward and Inverse Problems

Mathematical Methods in the Applied Sciences, EarlyView.
ABSTRACT This paper develops a mathematical framework for interpreting observations of solar inertial waves in an idealized setting. Under the assumption of purely toroidal linear waves on the sphere, the stream function of the flow satisfies a fourth‐order scalar equation.
Tram Thi Ngoc Nguyen, Damien Fournier, Laurent Gizon, Thorsten Hohage   +3 more
wiley   +1 more source

A localised subgrid scale model for fluid dynamical simulations in astrophysics [PDF]

Astronomy & Astrophysics, 2006
We present a one-equation subgrid scale model that evolves the turbulence energy corresponding to unresolved velocity fluctuations in large eddy simulations. The model is derived in the context of the Germano consistent decomposition of the hydrodynamical equations. The eddy-viscosity closure for the rate of energy transfer from resolved toward subgrid
Schmidt, W., Niemeyer, J. C., Hillebrandt, W.   +2 more
openaire   +4 more sources

Survey on AI‐Enabled Computer Vision Technologies and Applications for Space Robotic Missions

Journal of Field Robotics, EarlyView.
ABSTRACT This survey provides a comprehensive overview of recent advancements and challenges in Artificial Intelligence (AI)‐enabled computer vision (CV) techniques for space robotic missions, spanning critical phases such as Entry, Descent, and Landing (EDL), orbital operations, and planetary surface exploration.
Maciej Quoos, Steven Kay, Julia Wajoras, Robert Field, Evridiki V. Ntagiou, Fakher Mohammad, Yang Gao   +6 more
wiley   +1 more source

Mechanisms for Multi-Scale Structures in Dense Degenerate Astrophysical Plasmas

, 2016
Two distinct routes lead to the creation of multi--scale equilibrium structures in dense degenerate plasmas, often met in astrophysical conditions. By analyzing an e-p-i plasma consisting of degenerate electrons and positrons with a small contamination ...
Berezhiani, V. I., Mahajan, S. M., Shatashvili, N. L.   +2 more
core   +1 more source