SIMULATING FLAME INSTABILITIES WITH THE LATTICE-BOLTZMANN METHOD

International audienceLattice-Boltzmann (LB) method has recently emerged as an attractive alternative to Navier-Stokes equations for Computational Fluid Dynamics. However, use of LBM for reactive flows is scarce, mainlydue to the difficulty of implementing thermal thermodynamic closure. In this regard, recent progress on Lattice-Boltzmann methods for low mach combustion modelling will be presented. A hybrid methodcoupling LB and Finite-Difference (FD) solver will be detailed. The LB solver consists of a regularizedthermal Lattice Boltzmann method with Bhatnagar-Gross-Krook (BGK) collision operator. Thepressure is linked to the ideal gas law and the macroscopic variables are recovered using the momentsof equilibrium function on the standard lattices (D2Q9, D3Q19, etc.). Furthermore, using the Chapman-Enskog multiscale technique, Navier-Stokes equations can be recovered. The classical FD schemesare used to solve Energy and Species conservative equations. The method is compressible and incor-porates full thermo-fluid coupling. Along with recovering classical multi-component thermo-dynamicsclosure including component-specific variable specific heat capacity and transport properties, as well as non-unity Prandtl number.First, a preliminary model will be presented where the validations are performed with 1-D freely prop-agating flame and 2-D counter flow diffusion flame. Then, further developments of the model will bediscussed. The capabilities of the developed model to handle complex flame structures will be demon-strated using 2-D Double-Shear layer, 2-D Flame-Vortex interaction, 2-D Darrieus-Landau Instabilityand 3-D Taylor-Green Vortex incorporating both simplified and detailed chemistry. The results will becompared with experimental and numerical solutions. Hence, demonstrating the use of LB method forcomplex flame simulations