English
Related papers

Related papers: A robust DPG method for singularly perturbed react…

200 papers

We present an ultra-weak formulation of a hypersingular integral equation on closed polygons and prove its well-posedness and equivalence with the standard variational formulation. Based on this ultra-weak formulation we present a…

Numerical Analysis · Mathematics 2013-09-09 Norbert Heuer , Felipe Pinochet

The problem of identifying the diffusion parameter appearing in a nonlocal steady diffusion equation is considered. The identification problem is formulated as an optimal control problem having a matching functional as the objective of the…

Optimization and Control · Mathematics 2015-02-03 Marta D'Elia , Max Gunzburger

A nonsymmetric discontinuous Galerkin FEM with interior penalties has been applied to one-dimensional singularly perturbed reaction-diffusion problems. Using higher order splines on Shishkin-type layer-adapted meshes and certain graded…

Numerical Analysis · Mathematics 2017-05-12 Helena Zarin , Hans-Goerg Roos

A simple flux reconstruction for finite element solutions of reaction-diffusion problems is shown to yield fully computable upper bounds on the energy norm of error in an approximation of singularly perturbed reaction-diffusion problem. The…

Numerical Analysis · Mathematics 2019-06-26 Mark Ainsworth , Tomas Vejchodsky

In this article, using the weighted discrete least-squares, we propose a patch reconstruction finite element space with only one degree of freedom per element. As the approximation space, it is applied to the discontinuous Galerkin methods…

Numerical Analysis · Mathematics 2022-01-03 Di Yang , Yinnian He

In this paper, we propose a weak Galerkin finite element method (WG) for solving singularly perturbed convection-diffusion problems on a Bakhvalov-type mesh in 2D. Our method is flexible and allows the use of discontinuous approximation…

Numerical Analysis · Mathematics 2024-05-27 Shicheng Liu , Xiangyun Meng , Qilong Zhai

We explore a vexing benchmark problem for viscoelastic fluid flows with the discontinuous Petrov-Galerkin (DPG) finite element method of Demkowicz and Gopalakrishnan [1,2]. In our analysis, we develop an intrinsic a posteriori error…

Numerical Analysis · Mathematics 2019-12-24 Brendan Keith , Philipp Knechtges , Nathan V. Roberts , Stefanie Elgeti , Marek Behr , Leszek Demkowicz

In highly diffusion regimes when the mean free path $\varepsilon$ tends to zero, the radiative transfer equation has an asymptotic behavior which is governed by a diffusion equation and the corresponding boundary condition. Generally, a…

Numerical Analysis · Mathematics 2023-09-19 Qiwei Sheng , Cory Hauck , Yulong Xing

In this work we study a DPG method for an ultra-weak variational formulation of a reaction-diffusion problem. We improve existing a priori convergence results by sharpening an approximation result for the numerical flux. By duality…

Numerical Analysis · Mathematics 2017-12-21 Thomas Führer

This paper focuses on a nonlinear convection-diffusion equation with space and time-fractional Laplacian operators of orders $1<\beta<2$ and $0<\alpha\leq1$, respectively. We develop local discontinuous Galerkin methods, including Legendre…

Numerical Analysis · Mathematics 2026-02-11 Majid Rajabzadeh , Moein Khalighi

We investigate numerical behaviour of a convection diffusion equation with random coefficients by approximating statistical moments of the solution. Stochastic Galerkin approach, turning the original stochastic problem to a system of…

Numerical Analysis · Mathematics 2021-10-19 Pelin Çiloğlu , Hamdullah Yücel

Classical interior penalty discontinuous Galerkin (IPDG) methods for diffusion problems require a number of assumptions on the local variation of mesh-size, polynomial degree, and of the diffusion coefficient to determine the values of the,…

Numerical Analysis · Mathematics 2022-05-24 Zhaonan Dong , Emmanuil H. Georgoulis

We study a numerical method for convection diffusion equations, in the regime of small viscosity. It can be described as an exponentially fitted conforming Petrov-Galerkin method. We identify norms for which we have both continuity and an…

Numerical Analysis · Mathematics 2016-02-23 Snorre H. Christiansen , Tore G. Halvorsen , Torquil M. Sørensen

In this paper we investigate the variable coefficient two-sided fractional diffusion, advection, reaction equations on a bounded interval. It is known that the fractional diffusion operator may lose coercivity due to the variable…

Numerical Analysis · Mathematics 2022-03-23 Xiangcheng Zheng , V. J. Ervin , Hong Wang

In this paper, we present optimal error estimates of the local discontinuous Galerkin method with generalized numerical fluxes for one-dimensional nonlinear convection-diffusion systems. The upwind-biased flux with adjustable numerical…

Numerical Analysis · Mathematics 2022-09-09 Hongjuan Zhang , Boying Wu , Xiong Meng

We develop 3rd order maximum-principle-satisfying direct discontinuous Galerkin methods [8, 9, 19, 21] for convection diffusion equations on unstructured triangular mesh. We carefully calculate the normal derivative numerical flux across…

Numerical Analysis · Mathematics 2016-02-17 Zheng Chen , Hongying Huang , Jue Yan

In this article a simplified weak Galerkin finite element method is developed for the Dirichlet boundary value problem of convection-diffusion-reaction equations. The simplified weak Galerkin method utilizes only the degrees of freedom on…

Numerical Analysis · Mathematics 2018-08-29 Yujie Liu , Junping Wang

In this article we consider the numerical approximation of the convection-diffusion-reaction equation. One of the main challenges of designing a numerical method for this problem is that boundary layers occurring in the convection-dominated…

Numerical Analysis · Mathematics 2022-02-09 Paul Houston , Sarah Roggendorf , Kristoffer G. van der Zee

A singularly perturbed reaction-diffusion problem posed on the unit square in $\mathbb{R}^2$ is solved numerically by a local discontinuous Galerkin (LDG) finite element method. Typical solutions of this class of 2D problems exhibit…

Numerical Analysis · Mathematics 2024-10-01 Yao Cheng , Xuesong Wang , Martin Stynes

We investigate a numerical behaviour of robust deterministic optimal control problem subject to a convection diffusion equation containing uncertain inputs. Stochastic Galerkin approach, turning the original optimization problem containing…

Numerical Analysis · Mathematics 2023-03-01 Pelin Çiloğlu , Hamdullah Yücel