Presumed PDF model with tabulated chemical kinetics applied to spray combustion

The integration of tabulated chemistry into Lagrangian–Eulerian spray solvers offers substantial computational savings for diesel combustion simulations, yet no integrated and systematically validated solver of this kind is available within the OpenFOAM framework. This work presents , a new spray combustion solver built by extending the gaseous to the two-phase regime. The solver couples Lagrangian droplet tracking with precomputed flamelet libraries parameterized by mean mixture fraction, its variance, and the stoichiometric scalar dissipation rate, and accounts for turbulence–chemistry interaction through a presumed β -PDF approach. Three n-heptane chemical mechanisms, comprising 43, 68, and 188 species, were assessed in the counterflow configuration; only the 43-species mechanism of Liu et al. correctly reproduced ignition delays and the extinction limit at χ ₛₜ = 75.30~s⁻¹ , revealing that targeted reduction quality outweighs mechanism size. The solver was validated against constant-volume chamber measurements from Sandia National Laboratories covering six thermodynamic conditions. Under inert conditions, liquid and vapor penetration lengths and radial mixture fraction profiles agree well with experiments after calibrating the k – ε constants to c1ε = 1.55 and σ _ε = 1.4 . Under reactive conditions, the model reproduces the measured ignition delay and flame lift-off length with mean absolute deviations of about 13% and 17%, respectively, for Tₐ ≥ 1000 K; at Tₐ ≤ 900 K the deviations grow to 43–61% (ignition delay) and 10–46% (lift-off length), reflecting the known limitations of the reduced mechanism in the low-temperature chemistry regime. Relative to , the new solver reduces wall-clock time by a factor of approximately 3.3 under otherwise identical conditions.