DIRECT SIMULATION AND MODELING OF FLAME-WALL INTERACTION FOR PREMIXEDTURBULENT COMBUSTION

The interaction between turbulent premixed flames and walls is studied using a two-dimensional full Navier-Stokes solver with simple chemist ry. The effects of wall distance on the local and global flame structu re are investigated. Quenching distances and maximum wall heat fluxes during quenching are computed in laminar cases and are found to be com parable to experimental and analytical results. For turbulent cases, i t is shown that quenching distances and maximum heat fluxes remain of the same order as for laminar flames. Based on simulation results, a ' 'law-of-the-wall'' model is derived to describe the interaction betwee n a turbulent premixed flame and a wall. This model is constructed to provide reasonable behavior of flame surface density near a wall under the assumption that flame-wall interaction takes place at scales smal ler than the computational mesh. It can be implemented in conjunction with any of several recent flamelet models based on a modeled surface density equation, with no additional constraints on mesh size or time step. Preliminary tests of this model are presented for the case of a spark-ignited piston engine.