CERFACS CERFACS Scientific Activity Report Jan. 2010 â Dec. 2011

More documents

Recommendations

Info

3 Discontinuous Galerkin methods for time domain problems 3.1 A posteriori analysis for Maxwell equations S. Pernet The discontinuous Galerkin methods have become a classical tool for the simulation of wave propagation in heterogeneous media and complex domains. The EMA team contributes to the development of a high order Discontinuous Galerkin scheme for transient Maxwell’s equations in collaboration with the French Aerospace Lab (ONERA). Today, the a posteriori error analysis and automatic mesh adaptation have become important tools in numerical analysis of partial differential equations (PDE). Indeed, the quality of the solution is closely related to the quality of the mesh used. The automatic mesh adaptation has clearly proven its effectiveness. This technique allows to significantly reduce the computational cost (by reducing the number of degrees of freedom) and to achieve a numerical solution with the wanted accuracy. The quality of the solution is evaluated by using an a posteriori error estimator. The development of such tools remains a challenge in many situations. In particular, few results exist for the space-time adaptivity. This is especially true for Maxwell’s equations for which there are only results in the frequency domain. In the REI ”Recherche exploratoire et Innovation” project DIGATOP funding by the DGA (Direction Générale de l’Armement), we have initiated a research on the derivation of a posteriori error estimates in the frame of the time domain Maxwell equations. In the first time, we have proposed a reliable and an efficient a posteriori error indicator (in sense of the a posteriori error analysis) of residual type in order to control the space discretization error for the energy norm. The construction is based on a reconstruction technique [8] which reduces the a posteriori error analysis to a ”more simple” intermediate stationary problem. This reconstructed problem is based on the projector used to derive the optimal a priori error estimate of our scheme. One advantage of this type of estimator is the low computational cost. However, such an estimate involves many constants (not explicit) that can induce a pessimistic indicator. That is why, in a second step, we proposed estimators which do not involve undetermined constants. For that, we inspired of the approach established in [9, 10] : first, we give abstract error estimates which are independent of the numerical scheme used to obtain the approximate solution. These estimates then guide the construction of explicit estimators which are then scheme dependent. These are local reconstruction techniques which allow to obtain efficient error indicators. [8] Ch. Makridakis and R. Nochetto, Elliptic reconstruction and a posteriori error estimates for parabolic problems, SIAM J. Numer. Anal. 41 (2003), no. 4, 1585-1594. [9] A. Ern, A. F. Stephansen, M. Vohralik, Guaranteed and Robust discontinuous Galerkin a posteriori error estimates for convection-diffusion-reaction problem, J. Comput. Appl. Math., 234, 114–130 (2010). [10] M. Vohralik, A posteriori error estimates for lowest-order mixed finite element discretizations of convection-diffusion-reaction equations, SIAM J. Numer. Anal. 45 (2007), 1570-1599. [11] S. Pernet, Rapport d’avancement T0 +6 pour la tâche 2 du projet DIGATOP : Mise au point d’un estimateur a posteriori pour FEMGD, CR-EMA-09-134, 2009. 60 Jan. 2010 – Dec. 2011
ELECTROMAGNETISM AND ACOUSTICS TEAM 3.2 Space-time refinement for elastodynamic equation Y. Dudouit, L. Giraud, F. Millot and S. Pernet The numerical simulation of the propagation of seismic waves is a central concern for the seismic exploration. An important research activity is focused on finding fast and accurate numerical methods to solve the elastodynamic equation. In particular, the problematic of the software optimization by reducing the computational costs is crucial to our research. For the solution of the elastodynamic equation on meshes with local refinements, we are currently collaborating with Total to design a parallel implementation of a local time refinement technique on top of a discontinuous Galerkin space discretization. This latter technique enables to manage non-conforming meshes suited to deal with multiblock approaches that capture the locally refined regions. This work is developed in the framework of Yohann Dudouit PhD thesis. A software prototype is currently developed to address these simulations. CERFACS ACTIVITY REPORT 61
Page 1 and 2:
CERFACS Scientific Activity Report
Page 3 and 4:
Table des matières 1 Foreword xiii
Page 5 and 6:
9 Publications 40 9.1 Books . . . .
Page 7 and 8:
3 The OpenPALM coupler 104 3.1 Intr
Page 9 and 10:
Table des figures CERFACS chart as
Page 11 and 12:
TABLE DES FIGURES 6 Computational F
Page 13 and 14:
Foreword Welcome to the 2010-2011 S
Page 15 and 16:
CERFACS STRUCTURE CERFACS organizat
Page 17 and 18:
CERFACS STAFF NAME POSITION PERIOD
Page 19 and 20:
CERFACS STAFF SILVA GARZON Ph.D stu
Page 21 and 22:
CERFACS STAFF NAME POSITION PERIOD
Page 23:
CERFACS Wide-Interest Seminars Pete
Page 27 and 28:
1 Introduction 1.1 Introduction The
Page 29 and 30:
PARALLEL ALGORITHMS PROJECT success
Page 31 and 32:
PARALLEL ALGORITHMS PROJECT Visitor
Page 33 and 34: 3 List of Members of HiePACS HiePAC
Page 35 and 36: 4 Dense and Sparse Matrix Computati
Page 37 and 38: PARALLEL ALGORITHMS PROJECT Working
Page 39 and 40: 5 Iterative Methods and Preconditio
Page 41 and 42: PARALLEL ALGORITHMS PROJECT 5.5 Pre
Page 43 and 44: PARALLEL ALGORITHMS PROJECT We are
Page 45 and 46: PARALLEL ALGORITHMS PROJECT is to e
Page 47 and 48: PARALLEL ALGORITHMS PROJECT automor
Page 49 and 50: PARALLEL ALGORITHMS PROJECT 7.4 Sol
Page 51 and 52: PARALLEL ALGORITHMS PROJECT precond
Page 53 and 54: PARALLEL ALGORITHMS PROJECT 7.16 An
Page 55 and 56: PARALLEL ALGORITHMS PROJECT solutio
Page 57 and 58: 8 Conferences and Seminars 8.1 Conf
Page 59 and 60: PARALLEL ALGORITHMS PROJECT Decembe
Page 61 and 62: PARALLEL ALGORITHMS PROJECT July WC
Page 63 and 64: PARALLEL ALGORITHMS PROJECT Septemb
Page 65 and 66: PARALLEL ALGORITHMS PROJECT [ALG15]
Page 67: PARALLEL ALGORITHMS PROJECT [ALG54]
Page 71 and 72: 1 Overview presentation The main ex
Page 73 and 74: ELECTROMAGNETISM AND ACOUSTICS TEAM
Page 83: ELECTROMAGNETISM AND ACOUSTICS TEAM
Page 93: ELECTROMAGNETISM AND ACOUSTICS TEAM
Page 97 and 98: 1 Introduction Data assimilation is
Page 99 and 100: DATA ASSIMILATION 2.3 Calibrating o
Page 101 and 102: 3 Data assimilation for atmospheric
Page 103 and 104: DATA ASSIMILATION BECM using or not
Page 105 and 106: DATA ASSIMILATION the potential vor
Page 107 and 108: DATA ASSIMILATION A two years simul
Page 109 and 110: DATA ASSIMILATION FIG. 4.1: Reducti
Page 111 and 112: DATA ASSIMILATION FIG. 4.3: April 2
Page 113 and 114: DATA ASSIMILATION by a surface mode
Page 115 and 116: 6 Data assimilation with EDF neutro
Page 117 and 118: DATA ASSIMILATION demonstrate that
Page 119 and 120: DATA ASSIMILATION [DA13] S. Massart
Page 121: 4 Coupling tools and HPC Climate Mo
Page 124 and 125: 2 The OASIS coupler The OASIS coupl
Page 126 and 127: THE OASIS COUPLER 2.3 OASIS4 Since
Page 128 and 129: 3 The OpenPALM coupler 3.1 Introduc
Page 130 and 131: THE OPENPALM COUPLER In the NitroEu
Page 132 and 133: 4 HPC Climate modelling 4.1 General
Page 134 and 135:
5 Publications 5.1 Conference Proce
Page 137:
5 Climate Variability and Global Ch
Page 140 and 141:
2 Climate variability and predictab
Page 142 and 143:
CLIMATE VARIABILITY AND PREDICTABIL
Page 144 and 145:
CLIMATE VARIABILITY AND PREDICTABIL
Page 146 and 147:
CLIMATE CHANGE AND IMPACT STUDIES a
Page 148 and 149:
CLIMATE CHANGE AND IMPACT STUDIES b
Page 150 and 151:
PUBLICATIONS [CM15] Y. Kwon, C. Des
Page 153 and 154:
1 Introduction The CFD (Computation
Page 155 and 156:
2 Combustion The research activity
Page 157 and 158:
COMPUTATIONAL FLUID DYNAMICS rate-o
Page 159 and 160:
COMPUTATIONAL FLUID DYNAMICS FIG. 2
Page 161 and 162:
COMPUTATIONAL FLUID DYNAMICS an iss
Page 163 and 164:
COMPUTATIONAL FLUID DYNAMICS TU Ber
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
COMPUTATIONAL FLUID DYNAMICS design
Page 171 and 172:
COMPUTATIONAL FLUID DYNAMICS (a) (b
Page 173 and 174:
COMPUTATIONAL FLUID DYNAMICS 3.1.5
Page 175 and 176:
Page 177 and 178:
Page 179 and 180:
Page 181 and 182:
COMPUTATIONAL FLUID DYNAMICS (a) Ve
Page 183 and 184:
COMPUTATIONAL FLUID DYNAMICS The cl
Page 185 and 186:
Page 187 and 188:
COMPUTATIONAL FLUID DYNAMICS (a) Do
Page 189 and 190:
Page 191 and 192:
5 Publications 5.1 Conferences Proc
Page 193 and 194:
COMPUTATIONAL FLUID DYNAMICS [CFD34
Page 195 and 196:
Page 197 and 198:
Page 199 and 200:
Page 201:
7 Aviation and Environment
Page 204 and 205:
INTRODUCTION instead of regular ker
Page 206 and 207:
SIMULATIONS OF AIRCRAFT WAKES AND R
Page 208 and 209:
Page 210 and 211:
Page 212 and 213:
LARGE SCALE ATMOSPHERIC COMPOSITION
Page 214 and 215:
LARGE SCALE ATMOSPHERIC COMPOSITION
Page 216:
PUBLICATIONS 4.2 Technical Reports
show all

CERFACS CERFACS Scientific Activity Report Jan. 2010 â Dec. 2011

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?

CERFACS CERFACS Scientific Activity Report Jan. 2010 â Dec. 2011