1 Evaluation of numerical strategies for LES of

Predicting particle dispersion in recirculating two-phase flows is a key issue for react-ing flows. In this study, Euler/Euler and Euler/Lagrange LES formulations have been compared in the bluff-body configuration from Borée et al. (2001) where glass beads are injected into a complex recirculating flow. These tests are performed for non-reacting, non-evaporating sprays but are mandatory validations before computing realistic com-bustion chambers. Two different solvers (one explicit and compressible and the other implicit and incompressible) have also been tested on the same configuration. Results show that the gas flow is well predicted by both solvers. The dispersed phase is also well predicted but the Lagrange solver predicts RMS values more precisely. The importance of inlet boundary conditions for the gas and the dispersed phase is revealed through various tests. 1. Motivations and objectives Today, RANS (Reynolds-averaged Navier-Stokes) equations are routinely solved to de-sign combustion chambers, for both gaseous and liquid fuels. Recently, in order to provide better accuracy for the prediction of mean flows but also to give access to unsteady phe-nomena occurring in combustion devices (such as instabilities, flashback or quenching), Large-Eddy Simulation (LES) has been extended to reacting flows. The success of these approaches for gaseous flames in the last years (Caraeni et al. 2000; Chakravarthy &amp