Temporal and spatial persistence of combustion fronts

TL;DR

This paper investigates the persistence properties of slow combustion fronts in paper, finding agreement with KPZ universality class predictions for temporal behavior but noting deviations in spatial and transient properties due to additional scales.

Contribution

It provides the first measurement of spatial and temporal persistence exponents for combustion fronts and compares them with theoretical predictions, highlighting non-Markovian effects.

Findings

Temporal persistence exponents agree with KPZ predictions.

Spatial persistence shows deviations from theory.

Transient behavior is non-Markovian due to additional scales.

Abstract

The spatial and temporal persistence, or first-return distributions are measured for slow combustion fronts in paper. The stationary temporal and (perhaps less convincingly) spatial persistence exponents agree with the predictions based on the front dynamics, which asymptotically belongs to the Kardar-Parisi-Zhang (KPZ) universality class. The stationary short-range and the transient behavior of the fronts is non-Markovian and the observed persistence properties thus do not agree with the theory. This deviation is a consequence of additional time and length scales, related to the crossovers to the asymptotic coarse-grained behavior.