Characterization of flow field and combustion dynamics in a novel pressurized side-wall quenching burner using high-speed PIV/OH-PLIF measurements

A novel, pressurized side-wall quenching (SWQ) burner test rig enabling investigations on flame-wall interactions (FWI) of a fully premixed V-shaped flame at conditions mimicking some characteristics of practical devices, e.g. increased pressures and Reynolds numbers, is introduced within this study. Two operating cases featuring turbulent flow conditions at atmospheric and 3 bar operating pressure are defined and characterized based on velocity fields and flame front positions provided by simultaneous high-speed particle image velocimetry (PIV) and planar laser-induced fluorescence of the OH radical (OH-PLIF). For non-reacting conditions, profiles of mean velocities and mean velocity fluctuations are measured in addition to near-wall flow fields at locations where FWI occurs for chemically reacting conditions. For reacting conditions, near-wall flows are characterized in the vicinity of the quenching zone. Based on measured fluctuations of the streamwise velocity component, the turbulent flame is classified at the transition from the wrinkled to the corrugated flamelet regime. Using the derived flame front positions, the instantaneous flame-wall interaction is classified into SWQ-like, head-on quenching (HOQ)-like and multi-zone quenching events and the transition between these scenarios is identified by means of OH-PLIF image sequences. A statistical analysis of the flame front topology is performed based on the flame brush and deduced frequency distributions. Statistically significant differences between both operating cases are confirmed by chi-squared homogeneity tests.