Global sensitivity analysis and uncertainty quantification of soot formation in an n-dodecane spray flame

•Active subspace method has been applied for the global sensitivity analysis for the soot formation in the Spray-A flame.•The active subspace for soot formation tends to one dimension as the spray flame approaches the quasi-steady state.•The controlling model parameters for the peak soot volume fraction on the centerline and its axial location has been revealed.•The 95% confidence interval due to the uncertainty of soot model, turbulence model and the combined effects of the two models has been quantified.