11H20 : n° 1156 Scalar fields sub-grid scale energy in Large-Eddy Simulation of turbulent flames: Mesh quality criterion

Luc Vervisch Pascale Domingo Guido Lodato Denis Veynante
INSA de Rouen & CNRS CORIA
Instantaneous, space-filtered and statistically time-averaged signals feature different characteristic length scales, which can be combined in dimensionless ratios. From a manufactured turbulent flame solution, a mesh quality criterion based on these ratios is discussed for reactive scalar LES.

12H00 : n° 1031 Use of direct and large eddy simulations for the development of multicomponent reacting compressible turbulent boundary layer wall model

Olivier Cabrit Franck Nicoud
CERFACS / Université Montpellier 2
A study of multicomponent reacting channel flows with significant heat transfer and low Mach number has been performed using a set of direct and large eddy simulations. The use of LES computations was needed to analyze accurate and relevant data of such flows at a sufficient Reynolds number and reasonable computational cost. The analysis of these data will be detailed leading to the development of an analytical wall model for predicting the total shear stress and heat flux at the wall.

12H20 : n° 668 A Finite-Volume Formulation for Fully Compressible Premixed Combustion using the Level Set Approach

Daniel Hartmann Matthias Meinke Wolfgang Schröder
Institute of Aerodynamics, RWTH Aachen University
The level set approach is used for fully compressible simulations of premixed combustion. The motivation of the present work is to numerically simulate thermo-acoustic combustion instabilities. These instabilities are excited by the interaction of heat release and pressure fluctuations, which can numerically only be accurately accounted for in fully compressible simulations. A major challenge is the discretization and the inclusion of the heat release due to combustion at the flame front. To this end, a finite-volume formulation, which uses the ideas of the ghost-fluid method [Fedkiw et al. J. Comp. Phys. 154, 393-427 (1999)], is developed based on a low-dissipation scheme which has been successfully used for large-eddy simulations of non-reacting flows.

12H40 : n° 1160 Effects of inlet/outlet boundary conditions on acoustic behaviour of a swirled burner

Camilo Silva Ammar Lamraoui Matthieu Leyko Thierry Schuller Franck Nicoud
CERFACS
Self-excited acoustic oscillations on an experimental swirled burner are studied both numerically and experimentally. Inlet acoustic impedance is measured experimentally and the sensibility of cavity acoustic mode frequencies to the inlet and outlet boundary conditions is investigated numerically by the use of an Helmholtz solver. Strong effect of the inlet impedance is observed on the frequencies of the acoustic cavity modes, and have to be taken into account for futures compressible LES.