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Related papers: A Two-Fluid Method for Ambipolar Diffusion

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This paper presents a spatial two-grid (STG) compact difference scheme for a two-dimensional (2D) nonlinear diffusion-wave equation with variable exponent, which describes, e.g., the propagation of mechanical diffusive waves in viscoelastic…

Numerical Analysis · Mathematics 2025-10-15 Hao Zhang , Kexin Li , Wenlin Qiu

We demonstrate the bi-directional propagation of more than 10 7 atoms (87 Rb) around a "stadium" shaped magnetic ring that encloses an area of 10.9 cm 2, with a flux density exceeding 10 11 atoms sec -1 cm -2 . Atoms are loaded into the…

Atomic Physics · Physics 2009-11-10 Saijun Wu , Wilbert Rooijakkers , Pierre Striehl , Mara Prentiss

A Hamiltonian reduction approach is defined, studied, and finally used to derive asymptotic models of internal wave propagation in density stratified fluids in two-dimensional domains. Beginning with the general Hamiltonian formalism of…

Fluid Dynamics · Physics 2023-07-26 R. Camassa , G. Falqui , G. Ortenzi , M. Pedroni , T. T. Vu Ho

We consider three-dimensional inviscid irrotational flow in a two layer fluid under the effects of gravity and surface tension, where the upper fluid is bounded above by a rigid lid and the lower fluid is bounded below by a flat bottom. We…

Analysis of PDEs · Mathematics 2019-07-24 Dag Nilsson

In this paper, we first establish a new fractional magnetohydrodynamic (MHD) coupled flow and heat transfer model for a generalized second-grade fluid. This coupled model consists of a fractional momentum equation and a heat conduction…

Numerical Analysis · Mathematics 2022-11-29 Xiaoqing Chi , Hui Zhang , Xiaoyun Jiang

Ambipolar diffusion is important in redistributing magnetic flux and in damping Alfven waves in molecular clouds. The importance of ambipolar diffusion on a length scale $\ell$ is governed by the ambipolar diffusion Reynolds number,…

Solar and Stellar Astrophysics · Physics 2015-05-19 Christopher F. McKee , Pak Shing Li , Richard I. Klein

The hydrodynamic Drude model (HDM) has been successful in describing the optical properties of metallic nanostructures, but for semiconductors where several different kinds of charge carriers are present, an extended theory is required. We…

Mesoscale and Nanoscale Physics · Physics 2018-03-14 Johan R. Maack , N. Asger Mortensen , Martijn Wubs

We present a comprehensive analytical study of radiative transfer using the method of moments and include the effects of non-isotropic scattering in the coherent limit. Within this unified formalism, we derive the governing equations and…

Earth and Planetary Astrophysics · Physics 2015-06-19 Kevin Heng , João M. Mendonça , Jae-Min Lee

We study dissipation in inhomogeneous two-dimensional electron systems. We predict a relatively strong current-induced spatial asymmetry in the heating of the electron and phonon systems -- even if the inhomogeneity responsible for the…

Mesoscale and Nanoscale Physics · Physics 2019-12-04 K. S. Tikhonov , I. V. Gornyi , V. Yu. Kachorovskii , A. D. Mirlin

The affine motion of two-dimensional (2d) incompressible fluids surrounded by vacuum can be reduced to a completely integrable and globally solvable Hamiltonian system of ordinary differential equations for the deformation gradient in ${\rm…

Analysis of PDEs · Mathematics 2020-01-30 Jay Roberts , Steve Shkoller , Thomas C. Sideris

The most common method to characterize the electrical response of a nanofluidic system is through its steady-state current-voltage response. In Part I, we demonstrated that this current-voltage response depends on the geometry, the layout…

Mesoscale and Nanoscale Physics · Physics 2025-06-11 Ramadan Abu-Rjal , Yoav Green

A two-dimensional water wave model based on conformal mapping is presented. The model is exact in the sense that it does not rely on truncated series expansions, nor suffer any numerical diffusion. Additionally, it is computationally highly…

Fluid Dynamics · Physics 2025-02-18 Andreas H. Akselsen

We describe a new Godunov algorithm for relativistic magnetohydrodynamics (RMHD) that combines a simple, unsplit second order accurate integrator with the constrained transport (CT) method for enforcing the solenoidal constraint on the…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Kris Beckwith , James M. Stone

We analyze the properties of steady and time-dependent C shocks under conditions prevailing in giant molecular clouds. For steady C shocks, we show that ionization equilibrium holds and use numerical integrations to obtain the shock…

Solar and Stellar Astrophysics · Physics 2015-05-30 Che-Yu Chen , Eve C. Ostriker

Though flux freezing is a good approximation frequently assumed for molecular clouds, ambipolar diffusion (AD) is inevitable at certain scales. The scale at which AD sets in can be a crucial parameter for turbulence and the star formation…

Solar and Stellar Astrophysics · Physics 2015-05-18 Hua-bai Li , Martin Houde , Shih-ping Lai , T. K. Sridharan

We present for astrophysical use a multi-dimensional numerical code to solve the equations for ideal magnetohydrodynamics (MHD). It is based on an explicit finite difference method on an Eulerian grid, called the Total Variation Diminishing…

Astrophysics · Physics 2016-08-30 Dongsu Ryu , T. W. Jones , Adam Frank

We develop an unconditionally stable numerical method for solving the coupling between two fluids (frictional forces/heatings, ionization, and recombination), and investigate the dynamical condensation process of thermally unstable gas that…

Astrophysics · Physics 2010-12-20 Tsuyoshi Inoue , Shu-ichiro Inutsuka

We present a numerical method to deal efficiently with large numbers of particles in incompressible fluids. The interactions between particles and fluid are taken into account by a physically motivated ansatz based on locally defined drag…

Condensed Matter · Physics 2016-08-31 W. Kalthoff , S. Schwarzer , G. H. Ristow , H. J. Herrmann

In the following work we apply the boundary element method to two-phase flows in shallow microchannels, where one phase is dispersed and does not wet the channel walls. These kinds of flows are often encountered in microfluidic…

Fluid Dynamics · Physics 2014-12-09 Mathias Nagel , François Gallaire

The coupling state between ions and neutrals in the interstellar medium plays a key role in the dynamics of magnetohydrodynamic (MHD) turbulence, but is challenging to study numerically. In this work, we investigate the damping of MHD…

Astrophysics of Galaxies · Physics 2023-11-13 Yue Hu , Siyao Xu , Lev Arzamasskiy , James M. Stone , A. Lazarian