Lattice-Boltzmann modeling of the quiet and unstable PRECCINSTA burner modes

Abstract

Recent studies have shown that Lattice-Boltzmann methods are indeed very promising in the field of reactive flows. More work is required, however, to demonstrate its ability to tackle complex reacting cases, as no study – to the authors’ knowledge – involves simultaneously high Reynolds flows (for which the collision kernel needs specific care), complex geometries (for which models are required at the wall boundaries), and non-uniform grids (where non-conform meshes need to be addressed).The present study intends to fill that gap, by investigating the well-known PRECCINSTA burner, including (i) characteristic boundary conditions, (ii) classical turbulent combustion modeling, (iii) multi-level grid refinements. Combining these elements, numerical simulations of the PRECCINSTA burner are carried out, both for the quiet (φ=0.83) and unstable regimes (φ=0.7). In both regimes, results are consistent with those obtained with classical (Navier–Stokes) solvers, but at a much lower cost. In particular, it is the first time that successful prediction of thermoacoustic instabilities in a complex burner is shown in the framework of Lattice-Boltzmann methods.