EBookClubs

Read Books & Download eBooks Full Online

EBookClubs

Read Books & Download eBooks Full Online

Book New Factorizable Discretizations for the Euler Equations

Download or read book New Factorizable Discretizations for the Euler Equations written by Boris Diskin and published by . This book was released on 2002 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: A multigrid method is defined as having textbook multigrid efficiency (TME) if solutions to the governing system of equations are attained in a computational work that is a small (less than 10) multiple of the operation count in one target-grid residual evaluation. Away to achieve TME for the Euler and Navier-Stokes equations is to apply the distributed relaxation method thereby separating the elliptic and hyperbolic partitions of the equations. Design of a distributed relaxation scheme can be significantly simplified if the target discretization possesses two properties: (1) factorizability, and (2) consistent approximations for the separate factors. The first property implies that the discrete system determinant can be represented as a product of discrete factors, each of them approximating a corresponding factor of the determinant of the differential equations. The second property requires that the discrete factors reflect the physical anisotropies, be stable, and be easily solvable. In this paper, discrete schemes for the nonconservative Euler equations possessing properties (1) and (2) have been derived and analyzed. The accuracy of these scheme has been tested for subsonic flow regimes and is comparable with the accuracy of standard schemes. TME has been demonstrated in solving fully subsonic quasi-one-dimensional flow in a convergent/divergent channel.

Book Analysis of Boundary Conditions for Factorizable Discretizations of the Euler Equations

Download or read book Analysis of Boundary Conditions for Factorizable Discretizations of the Euler Equations written by Boris Diskin and published by . This book was released on 2002 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this article, several sets of boundary conditions or factorizable schemes corresponding to the steady-state compressible Euler equations are evaluated. The analyzed model is a one-dimensional constant-coefficient problem. Numerical tests have been performed for a fully subsonic quasi-one-dimensional flow in a convergent/divergent channel. This paper focuses on the effect of boundary-condition equations on stability and accuracy of the discrete solutions. Explicit correspondence between solutions and boundary conditions is established through a boundary-condition-sensitivity (BCS) matrix. The following new findings are reported: (1) Examples of stable discrete problems contradicting a wide-spread belief that employment of a one-order-lower approximation schemes in an O(h)-small region does not affect the overall accuracy order of the solution have been found and explained. Such counterexamples can only be constructed for systems of differential equations. For scalar equations, the conventional wisdom is correct. (2) A negative effect of overspecified (although, exact) boundary conditions on accuracy and stability of the solution has been observed and explained. (3) Sets of practical boundary conditions for factorizable schemes providing stable second-order accurate solutions have been formulated. These schemes belong to a family of second-order schemes requiring second-order accuracy for some numerical-closure boundary conditions.

Book Numerical Solutions of the Euler Equations for Steady Flow Problems

Download or read book Numerical Solutions of the Euler Equations for Steady Flow Problems written by Albrecht Eberle and published by Vieweg+Teubner Verlag. This book was released on 2013-04-17 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: The last decade has seen a dramatic increase of our abilities to solve numerically the governing equations of fluid mechanics. In design aerodynamics the classical potential-flow methods have been complemented by higher modelling-level methods. Euler solvers, and for special purposes, already Navier-Stokes solvers are in use. The authors of this book have been working on the solution of the Euler equations for quite some time. While the first two of us have worked mainly on algorithmic problems, the third has been concerned off and on with modelling and application problems of Euler methods. When we started to write this book we decided to put our own work at the center of it. This was done because we thought, and we leave this to the reader to decide, that our work has attained over the years enough substance in order to justify a book. The problem which we soon faced, was that the field still is moving at a fast pace, for instance because hyper sonic computation problems became more and more important.

Book Lecture Notes On The Discretization Of The Boltzmann Equation

Download or read book Lecture Notes On The Discretization Of The Boltzmann Equation written by Nicola Bellomo and published by World Scientific. This book was released on 2003-01-24 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents contributions on the following topics: discretization methods in the velocity and space, analysis of the conservation properties, asymptotic convergence to the continuous equation when the number of velocities tends to infinity, and application of discrete models. It consists of ten chapters. Each chapter is written by applied mathematicians who have been active in the field, and whose scientific contributions are well recognized by the scientific community.

Book Recent Progress in the Theory of the Euler and Navier Stokes Equations

Download or read book Recent Progress in the Theory of the Euler and Navier Stokes Equations written by James C. Robinson and published by Cambridge University Press. This book was released on 2016-01-21 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rigorous mathematical theory of the Navier–Stokes and Euler equations has been a focus of intense activity in recent years. This volume, the product of a workshop in Venice in 2013, consolidates, surveys and further advances the study of these canonical equations. It consists of a number of reviews and a selection of more traditional research articles on topics that include classical solutions to the 2D Euler equation, modal dependency for the 3D Navier–Stokes equation, zero viscosity Boussinesq equations, global regularity and finite-time singularities, well-posedness for the diffusive Burgers equations, and probabilistic aspects of the Navier–Stokes equation. The result is an accessible summary of a wide range of active research topics written by leaders in their field, together with some exciting new results. The book serves both as a helpful overview for graduate students new to the area and as a useful resource for more established researchers.

Book Instability and Non uniqueness for the 2D Euler Equations After M Vishik

Download or read book Instability and Non uniqueness for the 2D Euler Equations After M Vishik written by Camillo De Lellis and published by Princeton University Press. This book was released on 2024-02-13 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: An essential companion to M. Vishik’s groundbreaking work in fluid mechanics The incompressible Euler equations are a system of partial differential equations introduced by Leonhard Euler more than 250 years ago to describe the motion of an inviscid incompressible fluid. These equations can be derived from the classical conservations laws of mass and momentum under some very idealized assumptions. While they look simple compared to many other equations of mathematical physics, several fundamental mathematical questions about them are still unanswered. One is under which assumptions it can be rigorously proved that they determine the evolution of the fluid once we know its initial state and the forces acting on it. This book addresses a well-known case of this question in two space dimensions. Following the pioneering ideas of M. Vishik, the authors explain in detail the optimality of a celebrated theorem of V. Yudovich in the sixties, which states that, in the vorticity formulation, the solution is unique if the initial vorticity and the acting force are bounded. In particular, the authors show that Yudovich’s theorem cannot be generalized to the L^p setting.

Book Unsteady Three dimensional Euler Equations Solutions on Dynamic Blocked Grids

Download or read book Unsteady Three dimensional Euler Equations Solutions on Dynamic Blocked Grids written by Dave M. Belk and published by . This book was released on 1987 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: An unsteady implicit Euler equation solution algorithm using finite volume discretization and flux-vector splitting is presented. The effect on time-accuracy of different time step sizes, different approximate factorizations, and formal first-order versus second-order time accuracy is determined by numerical experimentation on a NACA0012 airfoil undergoing pitch oscillations in transonic flow. It is shown that time step sizes corresponding to Courant numbers of 100 or more can produce time-accurate results if flow variable s are not rapidly changing. Due to better stability properties, the two-factor method gives better results than the six-factor method. Also, the second-order-time-accurate three point backward time discretization is shown to yield only slight improvement over the first-order-time-accurate backward Euler time discretization. Methods of obtaining time-accurate Euler solutions on blocked grids are analyzed and verified by comparing multi-block solutions with equivalent one-block solutions.

Book ICASE Semiannual Report

Download or read book ICASE Semiannual Report written by and published by . This book was released on 2002 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes research conducted at ICASE in applied mathematics, computer science, fluid mechanics, and structures and material sciences during the period October 1, 2000 through March 31, 2001.

Book Compact High Order Schemes for the Euler Equations

Download or read book Compact High Order Schemes for the Euler Equations written by Saul Abarbanel and published by . This book was released on 1988 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: An implicit approximate factorization (AF) algorithm is constructed which has the following characteristics. In 2-D: The scheme is unconditionally stable, has a 3 x 3 stencil and at steady state has a fourth order spatial accuracy. The temporal evolution is time accurate either to 1st or 2nd order through choice of parameter. In 3-D: The scheme has almost the same properties as in 2-D except that it is now only conditionally stable, with the stability condition (the CFL number) being dependent on the cell aspect ratios, Delta y/Delta x and Delta z/Delta x. The stencil is still compact and fourth order accuracy at steady state is maintained. Numerical experiments on a 2-D shock-reflection problem show the expected improvement over lower order schemes, not only in accuracy (measured by the L2 error) but also in the dispersion. It is also shown how the same technique is immediately extendable to Runge Kutta type schemes resulting in improved stability in addition to the enhanced accuracy. Keywords: Euler equations; Compact schemes; High order accuracy; Dispersion.

Book Recent Progress in the Theory of the Euler and Navier Stokes Equations

Download or read book Recent Progress in the Theory of the Euler and Navier Stokes Equations written by James Cooper Robinson and published by . This book was released on 2016 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rigorous mathematical theory of the Navier-Stokes and Euler equations has been a focus of intense activity in recent years. This volume, the product of a workshop in Venice in 2013, consolidates, surveys and further advances the study of these canonical equations. It consists of a number of reviews and a selection of more traditional research articles on topics that include classical solutions to the 2D Euler equation, modal dependency for the 3D Navier-Stokes equation, zero viscosity Boussinesq equations, global regularity and finite-time singularities, well-posedness for the diffusive Burgers equations, and probabilistic aspects of the Navier-Stokes equation. The result is an accessible summary of a wide range of active research topics written by leaders in their field, together with some exciting new results. The book serves both as a helpful overview for graduate students new to the area and as a useful resource for more established researchers.

Book Activities of ICASE

Download or read book Activities of ICASE written by and published by . This book was released on 2001 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Iterative Solvers for Discretized Stationary Euler Equations

Download or read book Iterative Solvers for Discretized Stationary Euler Equations written by Bernhard Pollul and published by . This book was released on 2009 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: