Mechanisms of Hydrocarbon Laminar Flame Speed Enhancement with Microwaves
Conference Paper
Overview
Identity
Other
View All
Overview
abstract
Advanced laser diagnostics have been performed on continuous and pulsed microwave driven laminar methane/air flames, further elucidating mechanisms that cause the observed enhancement of the flame speed and suggesting improved lower power methods to obtain the enhancement. In particular, filtered Rayleigh scattering (FRS) and particle image velocimetry (PIV) have provided quantitative temperature and flame speed measurements, respectively. In the 1.3kW continuous wave (CW) microwave testbed, increases in temperature of only 50 K to 125 K were measured in the products of laminar flames showing 20% flame speed enhancement. Interestingly, a 30 W average power, 1 s pulsed microwave has been shown to generate the same flame speed enhancement without any noticeable increase in the post flame gas temperature. This fact and the rather low heating seen in the CW microwave enhanced flame support the possibility that the observed flame speed increase might be generated by an interaction involving radicals within the narrow flame front. Additionally, the move towards pulsed microwave power has demonstrated that significant enhancement can be obtained with roughly 40 times less energy. Copyright 2008 by the American Institute of Aeronautics and Astronautics, Inc.
