An Arrhenius-based one-step reaction mechanism for hydrogen-air flames simulations in an extended range of operating conditions

An Arrhenius-based one-step scheme is derived for hydrogen-air combustion simulations. A Pre-Exponential Adjustment approach, based on an explicit analytical dependence of reaction rate parameters on equivalence ratio and pressure is adopted, together with a correction to improve the prediction of thermal flame thickness. The reduced scheme is validated by computations of one-dimensional unstrained and strained laminar premixed flames for a wide range of pressures ([1; 30] atm), unburned gas temperatures ([300; 800] K), and equivalence ratios ([0.4; 6.0]), with a good agreement of predicted main flame parameters between reduced and reference kinetic schemes. Coupled to a high-fidelity Navier–Stokes compressible solver, the reduced scheme is successfully proved for the numerical simulation of canonical configurations such as one-dimensional and two-dimensional premixed flames under several mixture conditions, with a significant improvement of computational efficiency.