Simulation of fingering behavior in smoldering combustion using a cellular automaton

Area of Science:

• Combustion Science
• Chemical Engineering
• Physics of Complex Systems

Background:

• Smoldering is a persistent, low-temperature, flameless combustion process driven by heat and mass transfer, and fuel chemistry.
• Fingering is a complex instability in smoldering combustion, occurring in thin fuels with limited oxygen, characterized by distinct finger patterns.

Purpose of the Study:

• To develop and validate a multilayer cellular automaton model for simulating smoldering combustion.
• To reproduce and analyze the fingering instability phenomenon observed in previous experiments.

Main Methods:

• A multilayer cellular automaton model was developed, incorporating principles of heat transfer, oxygen availability, and fuel consumption.
• The model was used to simulate smoldering combustion under varying oxygen conditions to observe pattern formation.

Main Results:

• The model successfully reproduced three fingering regimes: isolated fingers, tip-splitting fingers, and a smooth continuous front.
• Decreasing oxygen speed below a critical value initiated fingering, with pattern characteristics correlating positively with oxygen consumption.

Conclusions:

• The cellular automaton model provides a valid and alternative approach for simulating complex smoldering combustion phenomena, including pattern formation.
• The model's ability to replicate experimental observations validates its predictive capabilities for various geometries and conditions.