Results 71 to 80 of about 32,630,588 (240)

Variational Partitioned Runge–Kutta Methods for Lagrangians Linear in Velocities

open access: yesMathematics, 2019
In this paper, we construct higher-order variational integrators for a class of degenerate systems described by Lagrangians that are linear in velocities.
Tomasz M. Tyranowski, Mathieu Desbrun
doaj   +1 more source

Implicit-Explicit Runge-Kutta schemes for numerical discretization of optimal control problems

open access: yes, 2012
Implicit-explicit (IMEX) Runge-Kutta methods play a major rule in the numerical treatment of differential systems governed by stiff and non-stiff terms.
Herty, Michael   +2 more
core   +1 more source

Beyond hydrogen: Process design of a biogas steam reformer for Fischer–Tropsch synthesis

open access: yesThe Canadian Journal of Chemical Engineering, EarlyView.
The effect of pressure and steam to carbon ratio on carbon conversion. Abstract We present an analysis of a pilot‐scale multi‐tubular biogas steam reforming reactor, part of a sustainable aviation fuel (SAF) development project in Brazil. The novelty of this work is the application of a new, validated power law kinetic model, specifically developed for
Rafael Belo Duarte   +3 more
wiley   +1 more source

Volterra Runge- Kutta Methods for Solving Nonlinear Volterra Integral Equations

open access: yesمجلة بغداد للعلوم, 2010
In this paper Volterra Runge-Kutta methods which include: method of order two and four will be applied to general nonlinear Volterra integral equations of the second kind. Moreover we study the convergent of the algorithms of Volterra Runge-Kutta methods.
Baghdad Science Journal
doaj   +1 more source

Optimal Explicit Strong Stability Preserving Runge--Kutta Methods with High Linear Order and optimal Nonlinear Order [PDF]

open access: yes, 2014
High order spatial discretizations with monotonicity properties are often desirable for the solution of hyperbolic PDEs. These methods can advantageously be coupled with high order strong stability preserving time discretizations.
Gottlieb, Sigal   +2 more
core  

Quenching the Hubbard Model: Comparison of Nonequilibrium Green's Function Methods

open access: yesContributions to Plasma Physics, EarlyView.
ABSTRACT We benchmark nonequilibrium Green's function (NEGF) approaches for interaction quenches in the half‐filled Fermi–Hubbard model in one and two dimensions. We compare fully self‐consistent two‐time Kadanoff–Baym equations (KBE), the generalized Kadanoff–Baym ansatz (GKBA), and the recently developed NEGF‐based quantum fluctuations approach (NEGF‐
Jan‐Philip Joost   +3 more
wiley   +1 more source

Stability Bounds for the Generalized Kadanoff‐Baym Ansatz in the Holstein Dimer

open access: yesContributions to Plasma Physics, EarlyView.
ABSTRACT Predicting real‐time dynamics in correlated systems is demanding: exact two‐time Green's function methods are accurate but often too costly, while the Generalized Kadanoff‐Baym Ansatz (GKBA) offers time‐linear propagation at the risk of uncontrolled behavior. We examine when and why GKBA fails in a minimal yet informative setting, the Holstein
Oscar Moreno Segura   +2 more
wiley   +1 more source

A Class of Two-Derivative Two-Step Runge-Kutta Methods for Non-Stiff ODEs

open access: yesJournal of Applied Mathematics, 2019
In this paper, a new class of two-derivative two-step Runge-Kutta (TDTSRK) methods for the numerical solution of non-stiff initial value problems (IVPs) in ordinary differential equation (ODEs) is considered.
I. B. Aiguobasimwin, R. I. Okuonghae
doaj   +1 more source

Efficient Explicit Time Stepping of High Order Discontinuous Galerkin Schemes for Waves

open access: yes, 2018
This work presents algorithms for the efficient implementation of discontinuous Galerkin methods with explicit time stepping for acoustic wave propagation on unstructured meshes of quadrilaterals or hexahedra.
Kormann, Katharina   +3 more
core   +1 more source

Coupling Fluid Neutrals to Gyrokinetic Plasma Dynamics for Edge and SOL Turbulence Simulations

open access: yesContributions to Plasma Physics, EarlyView.
ABSTRACT Accurate modeling of turbulent transport in magnetic confinement fusion devices requires extending first‐principles gyrokinetic simulations from the core to the edge and scrape‐off layer (SOL), where additional physics—particularly plasma–neutrals interactions—must be included.
Sabine Ogier‐Collin   +3 more
wiley   +1 more source

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