Tentative session assignment is listed below:
ID#: 34
Abstract Title: Steep Pressure Interactions With a Methane-Air Flame: The Inclusion of Multi-step Chemistry
Session Title: Flames
Session Date: 7/31/01
Session Start Time: 11:20 AM
Contributing Author: Yang, X.
Organization: University of Leeds
Country: U.K.
Authors: Xin-She Yang, Andy C. McIntosh, John Brindley
Short Abstract: The numerical computation of structures of one-dimensional methane-air flames over a wide range of conditions has been made. Several reduced schemes have been proposed and reproduce most of the chemistry from the earlier work. Most of the work on multi-step chemistry has focused on the computational simulations at steady-state or on using the partial-equilibirum approximations, for modelling the multi-layer structure of methane-air flames. In this paper, we intend to study sharp pressure disturbances and their interactions with premixed flames charactersed by three or four step chemistry. We focus on the effect of a sharp pressure drop on the time response and the effect of sharp pressure drops on methane premixed flames with multi-step chemistry. The time response of the mass burning rate of premixed flame for different values of minimum pressure has also been calculated so that a critical minimum pressure, leading to extinction of the premixed strained flame, is found, depending on the three activation energies and Lewis numbers. For sudden pressure drops, the flame is extinguished, if the pressure drop is sufficiently large. For large activation energies and low Lewis number, the flame is very susceptible to pressure changes.