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Related papers: Kinetic Scheme for Solving M1 Model of Radiative T…

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We develop a computational approach to locate the source of a steady-state gradient of diffusing particles from the fluxes through narrow windows distributed either on the boundary of a three dimensional half-space or on a sphere. This…

Statistical Mechanics · Physics 2020-01-07 U. Dobramysl , D. Holcman

In accelerating and supersonic media, the interaction of photons with spectral lines can be of ultimate importance. However, fully accounting for such line forces currently can only be done by specialised codes in 1-D steady-state flows.…

Solar and Stellar Astrophysics · Physics 2022-11-16 L. G. Poniatowski , N. D. Kee , J. O. Sundqvist , F. A. Driessen , N. Moens , S. P. Owocki , K. G. Gayley , L. Decin , A. de Koter , H. Sana

We present in this paper a multigroup model for radiation hydrodynamics to account for variations of the gas opacity as a function of frequency. The entropy closure model (M1) is applied to multigroup radiation transfer in a radiation…

High Energy Astrophysical Phenomena · Physics 2015-05-27 N. M. H. Vaytet , E. Audit , B. Dubroca , F. Delahaye

In this article, we are concerned with the analysis on the numerical reconstruction of the spatial component in the source term of a time-fractional diffusion equation. This ill-posed problem is solved through a stabilized nonlinear…

Numerical Analysis · Mathematics 2020-05-06 Daijun Jiang , Yikan Liu , Dongling Wang

We develop a numerical a framework to study phoretic particle dynamics in two dimensions. The particles are modeled as chemically active rigid circles, which can emit or absorb a solute into surrounding fluid. The interaction between…

Soft Condensed Matter · Physics 2025-12-16 Zhe Gou , Alexander Farutin , Chaouqi Misbah

We present describe a new computer code that solves the radiative transfer problem on multi-resolution grids. If the cloud model is from an MHD simulation on a regular cartesian grid, criteria based for example on local density or velocity…

Astrophysics · Physics 2009-11-10 M. Juvela , P. Padoan

Biomedical optical imaging has a possibility of a comprehensive diagnosis of thyroid cancer in conjunction with ultrasound imaging. For improvement of the optical imaging, this study develops a higher order scheme for solving the…

Medical Physics · Physics 2016-03-15 Hiroyuki Fujii , Shinpei Okawa , Ken Nadamoto , Eiji Okada , Yukio Yamada , Yoko Hoshi , Masao Watanabe

For theoretical gas dynamics, the flow regimes are classified according to the Knudsen number. For computational fluid dynamics (CFD), the numerical flow field is the projection of the physical flow field onto the discrete space and time,…

Computational Physics · Physics 2018-05-28 Chang Liu , Kun Xu , Guangzhao Zhou

The Fractional Diffusion Equation (FDE) is a mathematical model that describes anomalous transport phenomena characterized by non-local and long-range dependencies which deviate from the traditional behavior of diffusion. Solving this…

Numerical Analysis · Mathematics 2023-11-14 Mohammad Partohaghighi , Emmanuel Asante-Asamani , Olaniyi S. Iyiola

We consider the numerical solution of coupled volume-surface reaction-diffusion systems having a detailed balance equilibrium. Based on the conservation of mass, an appropriate quadratic entropy functional is identified and an…

Numerical Analysis · Mathematics 2015-11-04 Herbert Egger , Klemens Fellner , Jan-Frederik Pietschmann , Bao Quoc Tang

We present a method to model the interaction and the dynamics of atoms excited to Rydberg states. We show a way to solve the optical Bloch equations for laser excitation of the frozen gas in good agreement with the experiment. A second…

Atomic Physics · Physics 2009-11-13 Amodsen Chotia , Matthieu Viteau , Thibault Vogt , Daniel Comparat , Pierre Pillet

Orbital-free density functional theory promises to deliver linear-scaling electronic structure calculations. This requires the knowledge of the non-interacting kinetic-energy density functional (KEDF), which should be accurate and must…

Materials Science · Physics 2024-12-12 Michael A. J. Mitchell , Teresa Del Aguila Ferrandis , Stefano Sanvito

To use a 3D numerical MHD experiment representing magnetic flux emerging into an open field region as a background field for tracing charged particles. The interaction between the two flux systems generates a localised current sheet where…

Solar and Stellar Astrophysics · Physics 2015-05-18 Karl Joakim Rosdahl , Klaus Galsgaard

In the article, new asymptotic approximation of the $n$th order is obtained and proposed to be used in calculations of radiation propagation without scattering in optically thick media; the asymptotic approximation is much simpler and more…

Instrumentation and Methods for Astrophysics · Physics 2020-12-23 S. A. Serov , S. S. Serova

Astrophysical plasmas are subject to a tight connection between magnetic fields and the diffusion of particles, which leads to an anisotropic transport of energy. Under the fluid assumption, this effect can be reduced to an…

Astrophysics of Galaxies · Physics 2016-01-13 Yohan Dubois , Benoît Commerçon

This article is concerned with the derivation of numerical reconstruction schemes for the inverse moving source problem on determining source profiles in (time-fractional) evolution equations. As a continuation of the theoretical result on…

Numerical Analysis · Mathematics 2021-03-26 Yikan Liu

We analyze numerically a forward-backward diffusion equation with a cubic-like diffusion function, -emerging in the framework of phase transitions modeling- and its "entropy" formulation determined by considering it as the singular limit of…

Analysis of PDEs · Mathematics 2010-08-31 Pauline Lafitte , Corrado Mascia

The present work focuses on the numerical approximation of the weak solutions of the shallow water model over a non-flat topography. In particular, we pay close attention to steady solutions with nonzero velocity. The goal of this work is…

Numerical Analysis · Mathematics 2025-01-08 Christophe Berthon , Victor Michel-Dansac

Heat diffusion has been widely used in brain imaging for surface fairing, mesh regularization and cortical data smoothing. Motivated by diffusion wavelets and convolutional neural networks on graphs, we present a new fast and accurate…

Computer Vision and Pattern Recognition · Computer Science 2020-01-20 Shih-Gu Huang , Ilwoo Lyu , Anqi Qiu , Moo K. Chung

We present a novel generalization of the two-stream method of radiative transfer, which allows for the accurate treatment of radiative transfer in the presence of strong infrared scattering by aerosols. We prove that this generalization…

Earth and Planetary Astrophysics · Physics 2017-10-04 Kevin Heng , Daniel Kitzmann