Effect of wall heat flux on flame temperature profiles during side-wall quenching using advanced diagnostics

Abstract

Flame-wall interaction (FWI) is a topic of increasing importance within combustion science. The fundamentals of FWI govern fuel efficiency, durability, and pollutant emissions in propulsion and power generation. Significant research has been dedicated towards FWI, but a complete understanding of heat loss on the premixed laminar flame structure (temperature and species) is lacking experimentally. An underlying reason for this knowledge gap is the lack of experimental measurements to provide spatially resolved temperature profiles with high precision and accuracy across the flame during FWI. In this work, hybrid fs/ps rotational coherent anti-Stokes Raman spectroscopy (HRCARS) is used to measure wall-normal gas temperature profiles through a flame during FWI within a dedicated side-wall quenching (SWQ) burner facility [1]. HRCARS measurements are performed simultaneously with phosphor thermometry to measure wall temperature and wall heat flux. OH planar laser induced fluorescence is also used to determine the quenching height relative to the HRCARS probe volume. These combinations of diagnostics are used to quantify the various changes in the premixed laminar flame temperature profile as a function of wall heat loss, which provides a valuable experimental database for numerical simulations.