Quasi‑DNS with chemical kinetics for a single multiple‑injection burner element under stable lean conditions for future gas turbine applications

We develop a Quasi‑DNS with chemical kinetics for a stable lean condition in a single multiple‑injection burner element for future gas turbine applications, as a reusable workflow for a coaxial mixing‑tube burner. Here, Quasi-DNS denotes a high-resolution, turbulence-model-free calculation; it is not DNS in the strict sense. The OpenFOAM‑based method includes: (i) a simplified 30° sector geometry capturing vortices at the mixing tube outlet, (ii) boundary conditions reproducing coaxial jets and preheated air, (iii) a reduced Correa methane-air mechanism compared with GRI 3.0 using Cantera, (iv) mesh-development and grid-sensitivity assessment based on flame structure and the squared gradient of mixture fraction, and (v) post‑processing with methane‑based flame index. Demonstration at an equivalence ratio ϕ = 0.45 shows limited in‑tube mixing and strong outlet vortices, yielding a more extended heat release region than the RANS solution.•A reusable high-resolution, turbulence-model-free Quasi‑DNS workflow with detailed methane-air chemistry is developed for a coaxial mixing‑tube burner.•The workflow combines a reduced methane-air mechanism, refined sector-domain meshes, and scalar-field diagnostics for characterizing mixing and heat release regions.•The workflow enables analysis of mixing and flame stabilization under stable lean conditions, and provides a high-resolution numerical reference under the stated assumptions for comparison with RANS-based calculations.