Sound generation by premixed flame annihilation with full and simple chemistry

This paper presents a numerical study of sound generation by premixed laminar flame annihilation with full and simple chemistry. Planar annihilation is examined from lean (phi = 0: 5) to rich (phi = 3) conditions, which correspond to (effective) Lewis numbers ranging from 0.5 to 2.0 respectively. The full chemistry simulations use a well known detailed mechanism for hydrogen-air mixtures [1,2]. The simple chemistry simulations are tuned such that the freely propagating laminar flame speed matched those from the detailed chemistry simulations at the same equivalence ratio. These simulations examine two, related issues. First, they are used to confirm whether the Lewis number plays a significant role in the sound generation process, as our previous, simple chemistry studies have found [3,4]. More generally, these simulations seek to determine whether the use of simple chemistry to model sound generation is reasonable. The importance of the Lewis number is confirmed, and the use of simple chemistry is found to be reasonable in some cases. (C) 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved.