Large Scale Finite Element Solvers for the Large Eddy Simulation of Incompressible Turbulent Flows

Large Scale Finite Element Solvers for the Large Eddy Simulation of Incompressible Turbulent Flows
Author: Oriol Colomés Gené
Publisher:
Total Pages: 261
Release: 2016
Genre:
ISBN:

Download Large Scale Finite Element Solvers for the Large Eddy Simulation of Incompressible Turbulent Flows Book in PDF, Epub and Kindle

In this thesis we have developed a path towards large scale Finite Element simulations of turbulent incompressible flows. We have assessed the performance of residual-based variational multiscale (VMS) methods for the large eddy simulation (LES) of turbulent incompressible flows. We consider VMS models obtained by different subgrid scale approximations which include either static or dynamic subscales, linear or nonlinear multiscale splitting, and different choices of the subscale space. We show that VMS thought as an implicit LES model can be an alternative to the widely used physical-based models. This method is traditionally combined with equal-order velocity-pressure pairs, since it provides pressure stabilization. In this work, we also consider a different approach, based on inf-sup stable elements and convection-only stabilization. In order to do so, we define a symmetric projection stabilization of the convective term using an orthogonal subscale decomposition. The accuracy and efficiency of this method compared with residual-based algebraic subgrid scales and orthogonal subscales methods for equal-order interpolation is also assessed in this thesis. Furthermore, we propose Runge-Kutta time integration schemes for the incompressible Navier-Stokes equations with two salient properties. First, velocity and pressure computations are segregated at the time integration level, without the need to perform additional fractional step techniques that spoil high orders of accuracy. Second, the proposed methods keep the same order of accuracy for both velocities and pressures. Precisely, the symmetric projection stabilization approach is suitable for segregated Runge-Kutta time integration schemes. This combination, together with the use of block-preconditioning techniques, lead to elasticity-type and Laplacian-type problems that can be optimally preconditioned using the balancing domain decomposition by constraints preconditioners. The weak scalability of this formulation have been demonstrated in this document. Additionally, we also contemplate the weak imposition of the Dirichlet boundary conditions for wall-bounded turbulent flows. Four well known problems have been mainly considered for the numerical experiments: the decay of homogeneous isotropic turbulence, the Taylor-Green vortex problem, the turbulent flow in a channel and the turbulent flow around an airfoil.

Large Eddy Simulation of Turbulent Incompressible Flows

Large Eddy Simulation of Turbulent Incompressible Flows
Author: Volker John
Publisher: Springer Science & Business Media
Total Pages: 270
Release: 2012-12-06
Genre: Technology & Engineering
ISBN: 3642186823

Download Large Eddy Simulation of Turbulent Incompressible Flows Book in PDF, Epub and Kindle

Large eddy simulation (LES) seeks to simulate the large structures of a turbulent flow. This is the first monograph which considers LES from a mathematical point of view. It concentrates on LES models for which mathematical and numerical analysis is already available and on related LES models. Most of the available analysis is given in detail, the implementation of the LES models into a finite element code is described, the efficient solution of the discrete systems is discussed and numerical studies with the considered LES models are presented.

Large Eddy Simulation for Incompressible Flows

Large Eddy Simulation for Incompressible Flows
Author: P. Sagaut
Publisher: Springer Science & Business Media
Total Pages: 600
Release: 2006
Genre: Computers
ISBN: 9783540263449

Download Large Eddy Simulation for Incompressible Flows Book in PDF, Epub and Kindle

First concise textbook on Large-Eddy Simulation, a very important method in scientific computing and engineering From the foreword to the third edition written by Charles Meneveau: "... this meticulously assembled and significantly enlarged description of the many aspects of LES will be a most welcome addition to the bookshelves of scientists and engineers in fluid mechanics, LES practitioners, and students of turbulence in general."

Large Eddy Simulation for Incompressible Flows

Large Eddy Simulation for Incompressible Flows
Author: Pierre Sagaut
Publisher: Springer Science & Business Media
Total Pages: 326
Release: 2013-03-09
Genre: Science
ISBN: 3662044161

Download Large Eddy Simulation for Incompressible Flows Book in PDF, Epub and Kindle

First concise textbook on Large-Eddy Simulation, a very important method in scientific computing and engineering From the foreword to the third edition written by Charles Meneveau: "... this meticulously assembled and significantly enlarged description of the many aspects of LES will be a most welcome addition to the bookshelves of scientists and engineers in fluid mechanics, LES practitioners, and students of turbulence in general."

Large-eddy Simulation Using the Finite Element Method

Large-eddy Simulation Using the Finite Element Method
Author:
Publisher:
Total Pages: 18
Release: 1993
Genre:
ISBN:

Download Large-eddy Simulation Using the Finite Element Method Book in PDF, Epub and Kindle

In a large-eddy simulation (LES) of turbulent flows, the large-scale motion is calculated explicitly (i.e., approximated with semi-empirical relations). Typically, finite difference or spectral numerical schemes are used to generate an LES; the use of finite element methods (FEM) has been far less prominent. In this study, we demonstrate that FEM in combination with LES provides a viable tool for the study of turbulent, separating channel flows, specifically the flow over a two-dimensional backward-facing step. The combination of these methodologies brings together the advantages of each: LES provides a high degree of accuracy with a minimum of empiricism for turbulence modeling and FEM provides a robust way to simulate flow in very complex domains of practical interest. Such a combination should prove very valuable to the engineering community.