Effect of binary diffusion and chemical kinetic parameter uncertainties in simulations of premixed and non-premixed laminar hydrogen flames

Using a two-step approach, which includes a screening method (based on Morris Method) followed by global sensitivity analysis (based on High-Dimensional Model Representation), the uncertainty-based sensitivity of binary diffusion coefficients and chemical kinetic parameters over the full uncertainty range are presented for both simulations of premixed and non-premixed hydrogen-oxidizer-diluent mixtures. By implementing realistic uncertainty factors for binary diffusion coefficients and chemical kinetic parameters, the measured experimental uncertainty of laminar flame propagation velocity S L 0 is shown to be greater than the uncertainty on predicted S L 0 propagated from the binary diffusion coefficient parametric space. For 1 and 15 atm laminar flame speed simulations, the propagated uncertainties (ϵ) due to separate perturbation of the diffusion coefficients and chemical parameters are 3–5% and 12–41% respectively. The values of ϵ for the extinction strain rate at 1 atm are 6–8% and 19–28%. In premixed flames, the propagated uncertainty of chemical parameters increases with pressure, whereas the propagated uncertainty of binary diffusion coefficients is not affected. Based on current flame property measurements (about 5–10%), these results indicate that the fundamental flame properties clearly offer the possibility of reducing the chemical kinetic parameter uncertainties but marginal or no possibility of reducing the diffusion coefficient uncertainties.