Spatial and Temporal Scales Coupling in Reactive Flows

We investigate the eigenvalue spectrum of the one-dimensional laminar premixed flame in a reactive mixture described by detailed mass-action kinetics. All the physical scales, spatial and temporal, inherent in a reacting system are accurately identified via eigenvalue analysis. The interplay between chemistry and transport is addressed via conducting a spectral analysis of the reactive flow structure. It revealed that reacting systems’ physical scales are coupled, the systems short wavelength modes are dominated by diffusion-based scales, coarse wavelength modes are dominated by reaction-based scales, and modes near a cross-over wavelength have scales dictated by a combination of reaction and diffusion effects.