PhD Defense: Pierre CAYOT – High order numerical schemes for Large Eddy Simulation on unstructured grids
Tuesday 26 April 2016 at 14h00
Phd Thesis SALLE DE CONFÉRENCE JEAN-CLAUDE ANDRÉ
Abstract:
This study will present the development and results of high-order Finite Volume schemes for unstructured grids. The goal is to prepare numerical tools to perform Large Eddy Simulations with the indutrial solver elsA. These numerical schemes are based on a directional approach in order to limitate the CPU cost and reduce the stencil. The convective part of the scheme needsto be high order and this is obtained by the use of gradients on a four-cell stencil. Two gradients are usedfor the convective part, the Green-Gauss gradient and the “UIG” gradient. For the diffusive part, the “UIG” gradient is used. It was developped during this study and allows to recover a second-order accurate scheme. This gradient was validated theorically and numerically on some test cases.High order numerical schemes were studied theorically with order and frequency analysis. It was shown that these schemes are fifth-order accurate on regular hexaedral elements and third order accurate on equilateral triangles. Following this analysis, these schemes were tested in 1D on an advection test case and were then validated on the convection of an isentropic vortex.
Keywords : Finite Volume, High Order convection scheme, Large Eddy Simulation, Unstructured, Directional stencil, Gradient
Jury:
Rodolphe TURPAULT Université de Bordeaux Referee
Jens Dominik MUELLER Queen Mary University of London Referee
Nicolas GOURDAIN ISAE Toulouse Member
Hugues DENIAU ONERA Toulouse Member
Vincent COUAILLER ONERA Châtillon Member
Eric LIPPINOIS SNECMA Industrial
Guillaume PUIGT CERFACS Toulouse Advisor