ON THE BEHAVIOR OF A COUPLED TRANSIENT FLAMELET/PDF TRANSPORT EQUATION MODEL FOR NONPREMIXED TURBULENT FLAMES

摘要

This work introduces a new methodology for the modeling of turbulent flames, based on the combination of two frequently used models: the Eulerian composition probability density function (PDF) transport equation model and the transient laminar flamelet model (TLFM). The current new coupled TLFM/PDF model aims to combine the advantages of both models while avoiding their disadvantages. The flame chosen in this work for the validation was experimentally studied by Barlow and Frank (Effects of Turbulence on Species Mass Fractions in Methane/Air Flames, Proc. Combust, Inst., 27, 1087-1095, 1998) and shows visible local extinction at around an axial distance of 30 jet radii and reignition farther downstream. Therefore, this eon-figuration is a good test case to study the capability of numerical models for flames with local extinction and reignition regions. The Eulerian composition PDF transport equation model with a four-step reduced chemistry and the coupled TLFM/PDF model are compared and validated against experiments.