Numerical study on the combustion characteristics of a H2-fueled novel micromix combustor with a twisted tape insert

Micromix combustion technology is a novel combustion organization technique that is capable of mitigating the issues of excessive NO x emissions and flashback during hydrogen combustion in gas turbines. In this study, numerical simulations were carried out on a twisted-tape-inserted single-nozzle micromix combustor, focusing on the influence of equivalence ratio ( φ = 0.3∼0.7) and mean velocity ( V m = 20∼60 m/s) on combustion characteristics. The results revealed that: (1) An increase in φ induces the flame to evolve from a V-shaped lifted flame to an M-shaped anchored flame, thereby significantly improving flame stability. Meanwhile, NO emissions increase with a rising φ but remain below 10 ppm@15%O 2 overall. At V m = 40 m/s and φ = 0.4, the NO emissions are as low as 0.238 ppm@15%O 2 . (2) V m exerts a relatively weak influence on flame morphology and NO emissions. (3) φ plays a dominant role in flame structure and NO emissions.