Heat Penetration in Reactive Porous Beds
Name: ANDRÉ VERÍSSIMO XAVIER
Publication date: 28/11/2025
Examining board:
Name |
Role |
|---|---|
| FLÁVIO LOPES FRANCISCO BITTENCOURT | Coorientador |
| MARCELO RISSO ERRERA | Examinador Externo |
| MARCIO FERREIRA MARTINS | Presidente |
| MIRIAM SUELY KLIPPEL | Examinador Interno |
| RAMON SILVA MARTINS | Examinador Interno |
Summary: This study investigates how the ignition method, diffusion-, and convection-driven influences heat penetration in a reactive porous bed of coconut-shell charcoal. A series of 28 controlled experiments were conducted under both diffusion- and convection-driven combustion modes, varying ignition protocols and thermocouple depths within a custom-designed combustion
cell. The temperature evolution was measured to delineate heat penetration zones, including water condensation, preheating, and chemical reaction fronts. Results reveal that in assisted ignition, continuous external heating sustains combustion and deepens heat penetration by maintaining high-temperature gradients. In contrast, non-assisted ignition, which relies solely on internal heat release, exhibits faster cooling and limited penetration due to early heat loss and extinction risk. Heat maps constructed from the data show broader preheating zones under diffusion conditions and more pronounced condensation layers under convection. These findings highlight the critical role of ignition conditions in modulating thermal gradients and sustaining smoldering fronts, with implications for fire safety, waste-to-energy systems, and porous media combustion modeling.
Keywords: Smoldering Combustion. Ignition. Porous Media. Charcoal. Diffusion. Convection
