Simultaneous flow field and species measurements and emission performance of a rich burn-quench-lean burn combustor

This study investigates the three-dimensional (3D) distributions of flow and flame, as well as the emissions performance of swirl spray flames in a rich burn-quench-lean burn combustor featuring a typical primary hole configuration. A modified emission prediction model is constructed by integrating the 3D reconstruction results of optical diagnostics and theoretical analyses. Simultaneous optical diagnostics, utilizing particle image velocimetry and hydroxyl radical (OH)-planar laser-induced fluorescence were employed to capture the flow and flame structures under elevated temperature and pressure conditions of 500 K and 5 atm, across three different fuel–air ratios (FAR). Multi-spanwise slice images of flow and flame were used to reconstruct the 3D distributions via interpolation, facilitating precise extraction of key flame parameters. The results highlighted distinct flame stabilization mechanisms for the swirl spray flame truncated by the primary jets at varying FARs. Furthermore, combustor emission performance, including nitrogen oxides (NOx) and combustion efficiency, was measured using gas analysis methods. A quantitative correlation model for NOx emission was proposed by using the variables measured by optical diagnostics, specifically focusing on swirl spray flames truncated by the primary jets.