TL;DR: An asymptotic-induced scheme for kinetic semiconductor equations with the diffusion scaling is developed and works uniformly for all ranges of mean free paths.
Abstract: An asymptotic-induced scheme for kinetic semiconductor equations with the diffusion scaling is developed. The scheme is based on the asymptotic analysis of the kinetic semiconductor equation. It works uniformly for all ranges of mean free paths. The velocity discretization is done using quadrature points equivalent to a moment expansion method. Numerical results for different physical situations are presented.
TL;DR: It is observed that the combination of the two time-split steps may yield hyperbolic-parabolic systems that are more advantageous, in both stability and efficiency, for numerical computations.
Abstract: Many kinetic models of the Boltzmann equation have a diffusive scaling that leads to the Navier--Stokes type parabolic equations as the small scaling parameter approaches zero. In practical applications, it is desirable to develop a class of numerical schemes that can work uniformly with respect to this relaxation parameter, from the rarefied kinetic regimes to the hydrodynamic diffusive regimes. An earlier approach in [S. Jin, L. Pareschi, and G. Toscani, SIAM J. Numer. Anal., 35 (1998), pp. 2405--2439] reformulates such systems into the common hyperbolic relaxation system by Jin and Xin for hyperbolic conservation laws used to construct the relaxation schemes and then uses a multistep time-splitting method to solve the relaxation system. Here we observe that the combination of the two time-split steps may yield hyperbolic-parabolic systems that are more advantageous, in both stability and efficiency, for numerical computations. We show that such an approach yields a class of asymptotic-preserving (AP) schemes which are suitable for the computation of multiscale kinetic problems. We use the Goldstein--Taylor and Carleman models to illustrate this approach.
TL;DR: This survey considers the development and mathematical analysis of numerical methods for kinetic partial differential equations, including the case of semi-Lagrangian methods, discrete-velocity models and spectral methods, and an overview of the current state of the art.
Abstract: In this survey we consider the development and mathematical analysis of numerical methods for kinetic partial differential equations. Kinetic equations represent a way of describing the time evolution of a system consisting of a large number of particles. Due to the high number of dimensions and their intrinsic physical properties, the construction of numerical methods represents a challenge and requires a careful balance between accuracy and computational complexity. Here we review the basic numerical techniques for dealing with such equations, including the case of semi-Lagrangian methods, discrete-velocity models and spectral methods. In addition we give an overview of the current state of the art of numerical methods for kinetic equations. This covers the derivation of fast algorithms, the notion of asymptotic-preserving methods and the construction of hybrid schemes.
339 citations
Cites background or methods from "A Numerical Method for Kinetic Semi..."
...A. Klar (1998a), ‘An asymptotic-induced scheme for non stationary transport equations in the diffusive limit’, SIAM J. Numer....
[...]
...…numerical methods for kinetic equations in diffusion regimes has been studied by several authors: see Jin et al. (1998), Jin and Pareschi (2000), Klar (1998a), Naldi and Pareschi (2000), Gosse and Toscani (2003), Buet and Cordier (2007), Lemou and Mieussens (2008), Carrillo, Goudon, Lafitte and…...
[...]
...Extensions of the IMEX methods and a short review of other approaches are reported (Jin, Pareschi and Toscani 2000, Klar 1998a, Lemou and Mieussens 2008, Boscarino, Pareschi and Russo 2013)....
[...]
...S. Tiwari and A. Klar (1998), ‘An adaptive domain decomposition procedure for Boltzmann and Euler equations’, J. Comput....
[...]
...Finally, let us mention that the above AP splitting in the case ψ = 0 was used by Klar (1998a, 1998b) and Naldi and Pareschi (1998)....
TL;DR: A new numerical scheme for linear transport equations based on a decomposition of the distribution function into equilibrium and nonequilibrium parts that is asymptotic preserving in the following sense: when the mean free path of the particles is small.
Abstract: We propose a new numerical scheme for linear transport equations. It is based on a decomposition of the distribution function into equilibrium and nonequilibrium parts. We also use a projection technique that allows us to reformulate the kinetic equation into a coupled system of an evolution equation for the macroscopic density and a kinetic equation for the nonequilibrium part. By using a suitable time semi-implicit discretization, our scheme is able to accurately approximate the solution in both kinetic and diffusion regimes. It is asymptotic preserving in the following sense: when the mean free path of the particles is small, our scheme is asymptotically equivalent to a standard numerical scheme for the limit diffusion model. A uniform stability property is proved for the simple telegraph model. Various boundary conditions are studied. Our method is validated in one-dimensional cases by several numerical tests and comparisons with previous asymptotic preserving schemes.
232 citations
Cites background from "A Numerical Method for Kinetic Semi..."
...Very recently, two classes of semi-implicit time discretization have been proposed by Klar [19] and Jin, Pareschi and Toscani [16] (see preliminary works in [15, 10] and extensions in [14, 13, 27, 20, 21], and another strategy by Gosse and Toscani [8, 9])....
TL;DR: This paper shows that the splitting technique for relaxation schemes can be applied to a large class of transport equations with continuous velocities, when one uses the even and odd parities of the transport equation.
Abstract: Many transport equations, such as the neutron transport, radiative transfer, and transport equations for waves in random media, have a diffusive scaling that leads to the diffusion equations. In many physical applications, the scaling parameter (mean free path) may differ in several orders of magnitude from the rarefied regimes to the hydrodynamic (diffusive) regimes within one problem, and it is desirable to develop a class of robust numerical schemes that can work uniformly with respect to this relaxation parameter. In an earlier work [Jin, Pareschi, and Toscani, SIAM J. Numer. Anal., 35 (1998), pp. 2405--2439] we handled this numerical problem for discrete-velocity kinetic models by reformulating the system into a form commonly used for a relaxation scheme for conservation laws [Jin and Xin, Comm. Pure Appl. Math., 48 (1995), pp. 235--277]. Such a reformulation allows us to use the splitting technique for relaxation schemes to design a class of implicit, yet explicitly implementable, schemes that work with high resolution uniformly with respect to the relaxation parameter. In this paper we show that such a numerical technique can be applied to a large class of transport equations with continuous velocities, when one uses the even and odd parities of the transport equation.
209 citations
Cites background from "A Numerical Method for Kinetic Semi..."
...Past progress on developing robust numerical schemes for transport equations that also work in the diffusive regimes has been strongly guided by the study of the diffusion limit [1, 9, 10, 11, 13, 15, 16, 17, 20, 19, 23, 24, 25]....
TL;DR: A numerical method to solve Boltzmann like equations of kinetic theory which is able to capture the compressible Navier-Stokes dynamics at small Knudsen numbers is developed based on the micro/macro decomposition technique, which applies to general collision operators.
TL;DR: In this paper, a balanced overview of the major methods currently available for obtaining numerical solutions in neutron and gamma ray transport is presented, focusing on methods particularly suited to the complex problems encountered in the analysis of reactors, fusion devices, radiation shielding, and other nuclear systems.
Abstract: This books presents a balanced overview of the major methods currently available for obtaining numerical solutions in neutron and gamma ray transport. It focuses on methods particularly suited to the complex problems encountered in the analysis of reactors, fusion devices, radiation shielding, and other nuclear systems. Derivations are given for each of the methods showing how the transport equation is reduced to sets of algebraic equations suitable for solution on a digital computer. The limitations of the methods and their suitability for different classes of problems are discussed in terms of computer memory, time requirements, and accuracy.
TL;DR: A linear hyperbolic system is constructed with a stiff lower order term that approximates the original system with a small dissipative correction and can be solved by underresolved stable numerical discretizations without using either Riemann solvers spatially or a nonlinear system of algebraic equations solvers temporally.
TL;DR: In this article, the authors present a mathematical model of Semiconductor Device Equations and a singular perturbation analysis of the problem of finding the number of parameters of a single SVM.
Abstract: 1. Introduction.- 2. Mathematical Modeling of Semiconductor Devices.- 3. Analysis of the Basic Stationary Semiconductor Device Equations.- 4. Singular Perturbation Analysis of the Stationary Semiconductor Device Problem.- 5. Discretisation of the Stationary Device Problem.- 6. Numerical Simulation - A Case Study.- Notation of Physical Quantities.- Mathematical Notation.- A. Device Geometry.- B. Scalars, Vectors and Matrices.- C. Functions.- D. Landau Symbols.- E. Linear Spaces of Functions and Norms.- F. Functionalanalytic Notations.