The objective of the present study is to validate an in-house Computational Fluid Dynamics (CFD) solver, called les3d-mp, developed for high-resolution numerical simulations of boundary layer combustion. les3d-mp is a low Mach number, Navier-Stokes flow solver and is based on: a second-order fractional-step implicit scheme for time integration; a second-order finite difference scheme for spatial discretization; a classical staggered computational grid framework; a direct matrix inversion solver for the pressure equation; a standard rectangular Cartesian mesh capability; and a parallel computing implementation based on Message Passing Interface (MPI). les3d-mp provides a choice between a number of modeling options for the treatment of turbulence, including direct numerical simulation (DNS), large eddy simulation (LES) and Reynolds-averaged Navier-Stokes (RANS); the present study corresponds to weak-to-moderate turbulence levels and adopts a DNS approach. Combustion is treated using a classical "equilibrium", infinitely fast-chemistry combustion model with mixture fraction and total enthalpy as principal variables; thermodynamic properties are evaluated using CHEMKIN databases. Thermal radiation transport is currently neglected. The present study considers a simple non-premixed wall flame configuration in which the fuel corresponds to pyrolysis products supplied by a thermally-degrading flat sample of polymethyl methacrylate (PMMA) and the oxidizer corresponds to a cross-flow of ambient air with controlled mean velocity and turbulence properties. This configuration was previously studied experimentally at the University of California at Berkeley; the air cross-flow features moderate turbulence levels, i.e. a free stream velocity of 2 m/s and turbulence intensities between 5 and 15%. The numerical simulations use an advanced inflow forcing technique to simulate the air cross-flow as well as experimental data to prescribe the fuel mass flux at the wall; the wall surface temperatures are currently prescribed using a simplified description. Comparisons between numerical results and experimental data are made in terms of flame structure and flame length. Current work is aimed at removing the simplifications adopted in the description of the wall surface temperatures and at evaluating the accuracy of the numerical predictions for the wall (convective) heat flux.
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