主燃孔射流与侧壁冷却气对燃烧室流场与释热场影响的光学诊断

Experimental methods were employed to investigate the flow field and flame structure of complex swirling spray flames in a rich burn-quench-lean burn (RQL) combustor with a typical primary jet and cooling air under elevated temperature and pressure conditions (500 K, 500 kPa). Simultaneous optical diagnostic techniques (particle image velocimetry, PIV and OH planar laser-induced fluorescence, OH-PLIF) were utilized to capture the flow and flame structures at multiple cross-sections of a single-sector combustor under varying fuel-air ratios conditions, with measurements performed along the incoming flow direction of the primary jets. These pioneering measurements revealed the trajectory of the primary jets and their interaction processes with the flow field and heat release field under the influence of the cooling air. Results indicated that the experimental data acquired along the incoming flow direction of the primary jets more effectively characterized the interaction between the primary jets and the swirling spray flames. The cooling air significantly altered the central recirculation zone formed by the primary jets. Under non-reacting conditions, as the cooling air increased, the negative axial velocity range of the recirculation zone decreased, and flow symmetry was disrupted. Under reacting conditions, the interaction between cooling air and flames led to asymmetric flame structures, with local quenching observed near the wall at a high fuel-air ratio.