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This paper presents a novel method for solving the 2D advection-diffusion equation using fixed-depth symbolic regression and symbolic differentiation without expression trees. The method is applied to two cases with distinct initial and…

Computation · Statistics 2024-11-12 Edward Finkelstein

This paper aims to reconstruct the initial condition of a hyperbolic equation with an unknown damping coefficient. Our approach involves approximating the hyperbolic equation's solution by its truncated Fourier expansion in the time domain…

Numerical Analysis · Mathematics 2023-08-28 Thuy T. Le , Linh V. Nguyen , Loc H. Nguyen , Hyunha Park

Sub-diffusion equations are used in a large range of applications including fluids, plasma physics and biology. Their mathematical analysis is advanced even if a much larger literature addresses super-diffusions. The goal of this paper is…

Analysis of PDEs · Mathematics 2025-07-29 Benoît Perthame , Min Tang

We propose a seamless multiscale method which approximates the macroscopic behavior of the passive advection-diffusion equations with steady incompressible velocity fields with multi-spatial scales. The method uses decompositions of the…

Numerical Analysis · Mathematics 2016-06-22 Yoonsang Lee , Bjorn Engquist

The global existence issue for the isentropic compressible Navier-Stokes equations in the critical regularity framework has been addressed in [7] more than fifteen years ago. However, whether (optimal) time-decay rates could be shown in…

Analysis of PDEs · Mathematics 2016-12-21 Raphaël Danchin , Jiang Xu

This article shows how to develop an efficient solver for a stabilized numerical space-time formulation of the advection-dominated diffusion transient equation. At the discrete space-time level, we approximate the solution by using…

Numerical Analysis · Mathematics 2023-06-30 Marcin Łoś , Paulina Sepulveda-Salas , Maciej Paszyński

We present a dimensionally split method for solving hyperbolic conservation laws on Cartesian cut cell meshes. The approach combines local geometric and wave speed information to determine a novel stabilised cut cell flux, and we provide a…

Computational Physics · Physics 2018-03-15 Nandan Gokhale , Nikos Nikiforakis , Rupert Klein

We use the hyperbolic subdiffusion equation with fractional time derivatives (the generalized Cattaneo equation) to study the transport process of electrolytes in media where subdiffusion occurs. In this model the flux is delayed in a…

Statistical Mechanics · Physics 2009-11-13 Tadeusz Kosztolowicz , Katarzyna D. Lewandowska

We model the evolution of the concentration field of macromolecules in a symmetric field-flow fractionation (FFF) channel by a one-dimensional advection-diffusion equation. The coefficients are precisely determined from the fluid dynamics.…

chao-dyn · Physics 2007-05-23 S. A. Suslov , A. J. Roberts

In this paper, we address a time-dependent one-dimensional linear advection-diffusion equation with Dirichlet homogeneous boundary conditions. The equation is solved both analytically, using separation of variables, and numerically,…

Analysis of PDEs · Mathematics 2023-12-12 Eeshwar Prasad Poudel , Pitambar Acharya , Jeevan Kafle , Shreeram Khadka

A new semi-analytical solution to the advection-dispersion-reaction equation for modelling solute transport in layered porous media is derived using the Laplace transform. Our solution approach involves introducing unknown functions…

Numerical Analysis · Mathematics 2020-09-29 Elliot J. Carr

The work presents integral solutions of the fractional subdiffusion equation by an integral method, as an alternative approach to the solutions employing hypergeometric functions. The integral solution suggests a preliminary defined profile…

Mathematical Physics · Physics 2011-03-09 Jordan Hristov

We consider solutions of hyperbolic conservation laws regularized with vanishing diffusion and dispersion terms. Following a pioneering work by Schonbek, we establish the convergence of the regularized solutions toward discontinuous…

Analysis of PDEs · Mathematics 2007-12-04 Cezar Kondo , Philippe G. LeFloch

The partially dissipative systems that characterize many physical phenomena were first pointed out by Godunov (1961), then investigated by Friedrichs-Lax (1971) who introduced the convex entropy, and later by Shizuta-Kawashima (1984,1985)…

Analysis of PDEs · Mathematics 2026-03-03 Ling-Yun Shou , Jiang Xu , Ping Zhang

We prove sharp estimates for the decay in time of solutions to a rather general class of non-local in time subdiffusion equations on a bounded domain subject to a homogeneous Dirichlet boundary condition. Important special cases are the…

Analysis of PDEs · Mathematics 2013-10-02 Vicente Vergara , Rico Zacher

We introduce in this paper the numerical analysis of high order both in time and space Lagrange-Galerkin methods for the conservative formulation of the advection-diffusion equation. As time discretization scheme we consider the Backward…

Numerical Analysis · Mathematics 2024-01-05 Rodolfo Bermejo , Manuel Colera

The advection-diffusion equation is studied via a global Lagrangian coordinate transformation. The metric tensor of the Lagrangian coordinates couples the dynamical system theory rigorously into the solution of this class of partial…

Fluid Dynamics · Physics 2007-05-23 X. Z. Tang , A. H. Boozer

In this study, the hyperbolic method is adopted to explore the flow field states of incompressible flow in a four-sided lid-driven square cavity. In particular, we focus on the flow bifurcation obtained at the critical Reynolds number $R_e…

Fluid Dynamics · Physics 2022-07-14 Hubert Baty

We prove optimal estimates for the decay in time of solutions to a rather general class of non-local in time subdiffusion equations in $\mathbb{R}^d$. An important special case is the time-fractional diffusion equation, which has seen much…

Analysis of PDEs · Mathematics 2014-03-10 Jukka Kemppainen , Juhana Siljander , Vicente Vergara , Rico Zacher

In this paper, some initial-boundary-value problems for the time-fractional diffusion equation are first considered in open bounded n-dimensional domains. In particular, the maximum principle well-known for the PDEs of elliptic and…

Analysis of PDEs · Mathematics 2012-05-08 Yuri Luchko