Flame/turbulence interaction in ammonia/air premixed flames at high karlovitz numbers

• DOI: 10.1016/j.proci.2022.09.010
• Publication Date: 2022-10-21T05:46:46Z
• Authors: Leilei Xu; Qingshuang Fan; Xin Liu; Xiao Cai; Arman Ahamed Subash; Christian Brackmann; Zhongshan Li; Marcus Aldén; Xue-Song Bai
• Keywords: Flame structure; Large-Eddy Simulation; Planar laser-induced fluorescence; Flame speed

Turbulent premixed flames subjected to extreme levels of turbulence exhibit reaction zone broadening and thinning. Instantaneous flame structures visualized using advanced laser diagnostic methods have shown significantly different behaviours flame/turbulence interaction in jet stabilized on burners sizes. This paper aims reconcile the controversy about Premixed ammonia/air are investigated owing importance ammonia future carbon-free energy system. Due low laminar speed mixture, intensity (u′/SL) can be 5 times higher than that methane/air at same velocities. Planar laser-induced fluorescence (PLIF) imaging large eddy simulation based detailed chemical kinetics carried out systematically study under conditions, with u′/SL up 240 Karlovitz number 3019. Consistent observation reported literature, zones show behaviour sizes similar conditions. It is found a spatially evolving process, not only depending local eddy/flame but also upstream history. The onset distributed take place positions located several orifice diameters above burner thereafter eddies self-produced layer due continuous vortex stretch interacting zone. larger integral length scales do fit directly inside zones, as such could broaden zones.