Equivalence Ratio Gradient Effects on Local Flame Front Topology and Heat Release Rate in Stratified, Iso-Octane/Air Turbulent V-Flames

Abstract

This thesis details the development and application of an experimental apparatus and methodology capable of quantifying the effects of partial premixing on the local behaviour of turbulent flames. A novel rectangular slot burner was used to generate controlled, transverse variations in mixture strength along its exit plane, such that turbulent, rod-stabilized V-flames could be anchored in reactant mixtures of varying mean gradients in equivalence ratio. A unique windowing approach was devised in which 3-pentanone tracer planar laser induced fluorescence (PLIF) of the reactants was used to determine an analysis region of interest (ROI) within the flame. Iso-contours of equivalence ratio (e.g.  = 0.95-1.05 for nearstoichiometric flame regions) were traced up to the mean position of the flame front to define the width of the ROI, which was specific to each mean  gradient flame condition. This analysis methodology enabled fair comparison among gradient settings, and ensured that any observed variation in local flame behaviour could be attributed specifically to mean  gradient effects, rather than simple mixture strength effects.To all my friends, starting from l