Transient CFD Dataset - Adelaide Jet in Hot Coflow (AJHC) This dataset contains the results of 5 transient CFD simulations of the Adelaide Jet in Hot Coflow (JHC) burner, an established benchmark for turbulent diluted combustion under MILD-like conditions. The simulations were performed with ANSYS Fluent 24R1 on a 2D axisymmetric mesh of approximately 35 000 quadrilateral cells. Additional information can be found in the provided `README.ipynb`. The burner consists of a water-cooled central jet (∅ 4.25 mm) issuing an equimolar H₂/CH₄ mixture into an annular coflow (∅ 82 mm) of hot combustion products. Two input parameters are dynamically varied: the jet Reynolds number Re ∈ [5 000, 10 000] and the coflow O₂ mass fraction Y_O2 ∈ [0.03, 0.09]. Five excitation profiles are provided, logarithmic chirp signals (training) and step inputs (test), designed to support data-driven reduced-order modelling of turbulent reacting flows. The CFD model was built using ANSYS Fluent 24R1 with: - Standard k-ε turbulence model (C_ε1 = 1.6) - Partially Stirred Reactor (PaSR) combustion model with integral-based mixing timescale (C_mix = 0.1) - Kee kinetic mechanism for H₂/CH₄ oxidation - Discrete Ordinates (DO) radiation model with WSGGM spectral properties - Time step: Δt = 1×10⁻⁵ s, fields sampled every 200 steps (sampling interval 2 ms) The outputs provided in each `.npz` file include: - Thermochemical scalar fields: CH4, CO, CO2, H, H2, H2O, N2, O, O2, OH (mole fractions) and temperature T [K] - 2D mesh node coordinates The coflow O₂ boundary condition Y_O2 is specified as a mass fraction. Please cite the dataset when using this material.