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Dynamic wetting poses a well-known challenge in classical sharp-interface formulation as the no-slip wall condition leads to a contact line singularity that is typically regularized with a Navier boundary condition, often requiring…

Fluid Dynamics · Physics 2025-11-13 Tomas Fullana , Stéphane Zaleski , Gustav Amberg

A kinetic model for granular mixtures is considered to study three different non-equilibrium situations. The model is based on the equivalence between a gas of elastic hard spheres subjected to a drag force proportional to the particle…

Soft Condensed Matter · Physics 2025-02-27 Pablo Avilés , David González Méndez , Vicente Garzó

Monitoring the atmospheric dispersion of pollutants is increasingly critical for environmental impact assessments. High-fidelity computational models are often employed to simulate plume dynamics, guiding decision-making and prioritizing…

Fluid Dynamics · Physics 2026-01-14 Ike Griss Salas , Megan R. Ebers , Jake Stevens-Haas , J. Nathan Kutz

This article demonstrates that flexible and statistically tractable multi-modal diffusion models can be attained by transformation of simple well-known diffusion models such as the Ornstein-Uhlenbeck model, or more generally a Pearson…

Methodology · Statistics 2013-04-04 Julie Forman , Michael Sørensen

Many important properties of granular fluids can be represented by a system of hard spheres with inelastic collisions. Traditional methods of nonequilibrium statistical mechanics are effective for analysis and description of the inelastic…

Soft Condensed Matter · Physics 2009-11-07 James W. Dufty , J. Javier Brey , James Lutsko

Diffusion of small particles is omnipresent in a plentiful number of processes occurring in Nature. As such, it is widely studied and exerted in almost all branches of sciences. It constitutes such a broad and often rather complex subject…

Statistical Mechanics · Physics 2023-01-11 Jakub Spiechowicz , Ivan G. Marchenko , Peter Hänggi , Jerzy Łuczka

An existence result is proved for a nonlinear diffusion problem of phase-field type, consisting of a parabolic system of two partial differential equations, complemented by Neumann homogeneous boundary conditions and initial conditions.…

Analysis of PDEs · Mathematics 2012-02-24 Pierluigi Colli , Gianni Gilardi , Paolo Podio-Guidugli , Jürgen Sprekels

The purpose of this paper is to provide equations to model the evolution of effective diffusion over a Riemannian fiber bundle (under the hypothesis of infinite diffusion rate along compact fibers). These equations are obtained by…

Mathematical Physics · Physics 2015-02-24 Carlos Valero Valdes

The reaction of volatile matter plays an important role in the process of bringing matter from the surface of the planet to the atmosphere. Therefore, by simulating the mixing and chemical reaction process of volatile matter in the…

Earth and Planetary Astrophysics · Physics 2023-01-06 Zihan Huang , Xuewei Yang

The present paper discusses the diffusion approximation of the linear Boltzmann equation in cases where the collision frequency is not uniformly large in the spatial domain. Our results apply for instance to the case of radiative transfer…

Analysis of PDEs · Mathematics 2015-03-23 Claude Bardos , Etienne Bernard , François Golse , Rémi Sentis

We study quasi-one-dimensional scattering of one and two particles with short-range interactions on a discrete lattice model in two dimensions. One of the directions is tightly confined by an arbitrary trapping potential. We obtain the…

Quantum Physics · Physics 2015-05-28 Manuel Valiente , Klaus Molmer

We consider a diffusion process on an evolving surface with a piecewise Lipschitz-continuous boundary from an energetic point of view. We employ an energetic variational approach with both surface divergence and transport theorems to derive…

Mathematical Physics · Physics 2018-10-19 Hajime Koba

Diffusion models have made rapid progress in generating high-quality samples across various domains. However, a theoretical understanding of the Lipschitz continuity and second momentum properties of the diffusion process is still lacking.…

Machine Learning · Computer Science 2024-10-15 Yingyu Liang , Zhenmei Shi , Zhao Song , Yufa Zhou

The interdiffusion of a solvent into a polymer melt has been studied using large scale molecular dynamics and Monte Carlo simulation techniques. The solvent concentration profile and weight gain by the polymer have been measured as a…

Soft Condensed Matter · Physics 2009-11-10 Mesfin Tsige , Gary S. Grest

Relativistic jets reside in high-energy astrophysical systems of all scales. Their interaction with the surrounding media is critical as it determines the jet evolution, observable signature, and feedback on the environment. During its…

High Energy Astrophysical Phenomena · Physics 2018-04-04 Richard Harrison , Ore Gottlieb , Ehud Nakar

We study here the random diffusion model. This is a continuum model for a conserved scalar density field $\phi$ driven by diffusive dynamics. The interesting feature of the dynamics is that the {\it bare} diffusion coefficient $D$ is…

Soft Condensed Matter · Physics 2009-11-13 Gene F. Mazenko

A jump-diffusion process along with a particle scheme is devised as an accurate and efficient particle solution to the Boltzmann equation. The proposed process (hereafter Gamma-Boltzmann model) is devised to match the evolution of all…

Computational Physics · Physics 2023-08-09 Fabian Mies , Mohsen Sadr , Manuel Torrilhon

We introduce a framework for model reduction of chain models for dissipative particle dynamics (DPD) simulations, where the characteristic size of the chain, pressure, density, and temperature are preserved. The proposed methodology reduces…

Soft Condensed Matter · Physics 2016-05-04 Nicolas Moreno , Suzana P. Nunes , Victor M. Calo

In this paper, we propose a lattice Boltzmann (LB) model for the generalized coupled cross-diffusion-fluid system. Through the direct Taylor expansion method, the proposed LB model can correctly recover the macroscopic equations. The cross…

Fluid Dynamics · Physics 2021-11-02 Chengjie Zhan , Zhenhua Chai , Baochang Shi

A quasi-one-dimensional analytic model is proposed for the internal fluid of rotating detonation combustors (RDCs). This model uses the shock-tube model that constrains the flow to have only a longitudinal component, while admitting the…

Fluid Dynamics · Physics 2017-12-11 R. Kawashima , I. Funaki , J. Fujii , A. Matsuo , K. Ishihara , J. Kasahara