English
Related papers

Related papers: ECOM: a fast and accurate solver for toroidal axis…

200 papers

The particle and momentum balance equations can be solved on concentric circular flux surfaces to determine the effective viscous drag present in a magnetized tokamak plasma in the low aspect ratio limit. An analysis is developed utilizing…

Plasma Physics · Physics 2007-10-16 Robert W. Johnson

The present study is a continuation of a previous one on "hyperelliptic" axisymmetric equilibria started in [Tasso and Throumoulopoulos, Phys. Plasmas 5, 2378 (1998)]. Specifically, some equilibria with incompressible flow nonaligned with…

Plasma Physics · Physics 2009-11-10 H. Tasso , G. N. Throumoulopoulos

We consider the mathematical analysis and numerical approximation of a system of nonlinear partial differential equations that arises in models that have relevance to steady isochoric flows of colloidal suspensions. The symmetric velocity…

Numerical Analysis · Mathematics 2021-08-09 Andrea Bonito , Vivette Girault , Diane Guignard , Kumbakonam R. Rajagopal , Endre Süli

This work presents a fast direct solver strategy for electromagnetic integral equations in the high-frequency regime. The new scheme relies on a suitably preconditioned combined field formulation and results in a single skeleton form plus…

First-arrival traveltime computation is crucial for many applications such as traveltime tomography, Kirchhoff migration, etc. There exist two major issues in conventional eikonal solvers: the source singularity issue and insufficient…

Computational Physics · Physics 2020-08-19 Kai Gao , Lianjie Huang

In this paper, we first propose a filter-based continuous Ensemble Eddy Viscosity (EEV) model for stochastic turbulent flow problems. We then propose a generic algorithm for a family of fully discrete, grad-div regularized, efficient…

Numerical Analysis · Mathematics 2025-08-15 Brandiece N. Berry , Md Mahmudul Islam , Muhammad Mohebujjaman , Neethu Suma Raveendran

We derive axisymmetric equilibrium equations in the context of the hybrid Vlasov model with kinetic ions and massless fluid electrons, assuming isothermal electrons and deformed Maxwellian distribution functions for the kinetic ions. The…

Plasma Physics · Physics 2024-06-06 D. A. Kaltsas , A. Kuiroukidis , P. J. Morrison , G. N. Throumoulopoulos

We develop a boundary integral equation-based numerical method to solve for the electrostatic potential in two dimensions, inside a medium with piecewise constant conductivity, where the boundary condition is given by the complete electrode…

Numerical Analysis · Mathematics 2024-03-28 Teemu Tyni , Adam R Stinchcombe , Spyros Alexakis

In this paper, we consider numerical approximation of an electrically conductive ferrofluid model, which consists of Navier-Stokes equations, magnetization equation, and magnetic induction equation. To solve this highly coupled, nonlinear,…

Numerical Analysis · Mathematics 2025-04-02 Jialin Xie , Xiaodi Zhang

A new approach to high pressure magnetically-confined plasmas is necessary to design efficient fusion devices. This paper presents an equilibrium combining two solutions of the Grad-Shafranov equation, which describes the…

Plasma Physics · Physics 2009-11-13 P. -A. Gourdain , S. C. Cowley , J. -N. Leboeuf

Nonlinear tranlational symmetric equilibria with up to quartic flux terms in the free functions, reversed magnetic shear and sheared flow are constructed in two ways: i) quasianalytically by an ansatz which reduces the pertinent generalized…

Plasma Physics · Physics 2019-02-20 Ap Kuiroukidis , G. N. Throumoulopoulos

We describe a numerical code to solve the equations for ideal magnetohydrodynamics (MHD). It is based on an explicit finite difference scheme on an Eulerian grid, called the Total Variation Diminishing (TVD) scheme, which is a…

Astrophysics · Physics 2009-10-22 Dongsu Ryu , T. W. Jones

We present an analytical model of the self-consistent equilibrium of a magnetic flux rope which is obtained in cylindrical geometry. The equilibrium azimuthal magnetic field and plasma pressure are determined in a self-consistent way…

Pattern Formation and Solitons · Physics 2024-02-19 Oleg K. Cheremnykh , Viktor Fedun , Volodymyr M. Lashkin

The hybrid Vlasov-Maxwell system of equations is suitable to describe a magnetized plasma at scales of the order of or larger than proton kinetic scales. An exact stationary solution is presented by revisiting previous results with a…

Plasma Physics · Physics 2018-06-06 F. Malara , O. Pezzi , F. Valentini

This paper presents an innovative continuous linear finite element approach to effectively solve biharmonic problems on surfaces. The key idea behind this method lies in the strategic utilization of a surface gradient recovery operator to…

Numerical Analysis · Mathematics 2024-04-30 Ying Cai , Hailong Guo , Zhimin Zhang

In this work, we design an entropy stable, finite volume approximation for the ideal magnetohydrodynamics (MHD) equations. The method is novel as we design an affordable analytical expression of the numerical interface flux function that…

Numerical Analysis · Mathematics 2015-10-01 Andrew R. Winters , Gregor J. Gassner

We propose a novel meshless method to compute harmonic maps and conformal maps for surfaces embedded in the Euclidean 3-space, using point cloud data only. Given a surface, or a point cloud approximation, we simply use the standard cubic…

Differential Geometry · Mathematics 2020-09-22 Tianqi Wu , Shing-Tung Yau

The electroencephalography (EEG) forward problem, the computation of the electric potential generated by a known electric current source configuration in the brain, is a key step of EEG source analysis. In this problem, it is often desired…

Medical Physics · Physics 2019-03-28 Axelle Pillain , Lyes Rahmouni , Francesco Andriulli

In this work we develop and analyze an adaptive finite element method for efficiently solving electrical impedance tomography -- a severely ill-posed nonlinear inverse problem for recovering the conductivity from boundary voltage…

Numerical Analysis · Mathematics 2019-05-16 Bangti Jin , Yifeng Xu , Jun Zou

The adoption of cardiovascular simulations for diagnosis and surgical planning on a patient-specific basis requires the development of faster methods than the existing state-of-the-art techniques. To address this need, we leverage the…

Numerical Analysis · Mathematics 2024-12-10 Dongjie Jia , Mahdi Esmaily