DOI: 10.1615/THMT-18
ISBN Print: 978-1-56700-468-7
ISBN Online: 978-1-56700-467-0
ISSN Print: 2377-2816
Investigation of reaction zone structure of lean methane−air turbulent premixed flames with OH−CH2O PLIF
ABSTRAKT
Simultaneous measurement of planar laser induced fluorescence (PLIF) for OH radical and formaldehyde (CH2O) were performed for methane−air laminar and turbulent premixed flames propagating in a constant volume vessel to investigate effects of Lewis and Karlovitz numbers (Le and Ka) on the relations between the OH, CH2O and the flame front curvature. The turbulent flames of the different ∅ were classified into the corrugated flamelets and thin reaction zone regimes in the turbulent combustion diagram. For ∅ = 1.0, which is Le = 1, the magnitude of the product of OH and CH2O is close to the corresponding laminar unstretched flame, and the product increases with the increase of flame front curvature, which is defined to be positive for convex towards the burnt side. For the lower Le cases, which are the lower ∅ cases, it is revealed that the opposite tendency can be observed.