Additive-manufactured Hencken burner for wide-range oxyfuel combustion of zero-carbon fuels

Oxyfuel combustion of zero-carbon fuels offers a promising pathway to carbon-neutral energy and propulsion systems but requires robust laboratory-scale flat-flame burners for fundamental research. This study introduces a laboratory-scale multi-element diffusion burner fabricated via additive manufacturing of 316L stainless steel, featuring an integrated micro-channel architecture for leak-free micro-mixing of fuel and oxidizer and structural fins for enhanced thermal resilience. The burner demonstrates superior flame stability and versatility across a wide range of conditions. These include CH4/NH3/H2 fuel blends with arbitrary compositions, wide global equivalence ratios (0.2-4.0 for CH4/H2 and 0.2-1.6 for NH3), O2 fraction in oxidizer up to 100%, and power loads varying by several orders of magnitude. In situ N2 spontaneous Raman scattering thermometry reveals uniform temperature distributions in CH4/NH3/H2-O2 flames, with post-flame temperatures up to 3000 K, while OH planar laser-induced fluorescence imaging confirms homogeneous radical distributions, stable flame anchoring, and well-defined reaction zones across varied operation regimes. These properties establish the burner as a reliable platform for investigating the kinetics of zero-carbon fuel combustion while also providing a quasi-one-dimensional, high-temperature environment for heterogeneous combustion studies.