Amer Avdic

A Numerical Study of the Flame Stabilization Mechanism Being Determined by Chemical Reaction Rates Submitted to Heat Transfer Processes

Abstract Large Eddy Simulations of a turbulent lean premixed stratified burner are conducted in order to determine the physical mechanisms that dominate the flame stabilization close to burner walls. The purpose of this work is both to provide insight into the underlying physics as well as to check whether the deficiencies found in previous simulations are related to an inappropriate heat transfer treatment. The simulation utilizes a three-dimensional detailed chemistry database in order to capture the chemical reaction rates based on local mixing and thermal conditions. The study is supplemented by very accurate wall temperature measurements to remove the large uncertainty revealed in the past for this configuration. The results obtained from the simulations are evaluated by means of a qualitative illustration of the different flame stabilizations and comparisons with experimental data.

High performance computing of the Darmstadt stratified burner by means of large eddy simulation and a joint ATF-FGM approach

Current trend in design and operation of industrial gas turbines or internal combustion engines implies using the lean-fuel and stratified conditions aiming at the reduction of the harmful emissions and efficiency improvement. This has led to an increasing use of computational methodology, which allows detailed insight into combustion physics and processes controlling the emission formation. In the present work, the Darmstadt stratified burner is investigated by means of Large Eddy Simulation, implemented into the in-house, finite-volume-based numerical code FASTEST. The code solves the incompressible, variable-density Navier–Stokes equations coupled with the species transport equations. It is parallelized via domain decomposition technique using message passing interface (MPI). The complex chemical mechanisms are described by tabulated detailed chemistry utilizing the Flamelet Generated Manifolds (FGM) approach combined with the Artificially Thickened Flame model (ATF). The results obtained are comparatively assessed along with the complementary measurements. In-depth analysis of the flow field is conducted based on numerical simulations. Further studies have been carried out with respect to grid resolution and scalability.