This work presents a model to simulate, animate and control smoldering combustion. Smoldering is a slow, flame-less, low temperature combustion that is sustained by chemical heat generated by fuel oxidation in an oxygen limited environment. In most cases under the right conditions it is the pathway to flaming. Researchers so far have focused on flaming combustion and we introduce smoldering to the graphic community.

In this work we use chemical oxidation reaction, chemical heat generation, heat diffusion, and oxygen diffusion to model smolder propagation. We simulate fuel oxidation, in voxelized space, which forms the basis of chemical heat release. This heat release is used to sustain and propagate smolder. As this combustion is flame-less, chemical heat is the only energy generating mechanism that drives this phenomenon. On oxidation the combustible portion of fuel converts to ash. Ash formed acts as an insulating layer on the fuel thus reducing heat loss, which helps in sustenance and propagation of smolder. The smoldering has a feature of being porous, and permeable to flow of diffused air. This porosity acts as a way to get oxygen through the fuel to facilitate and sustain fuel oxidation. We model ash and wind as they play a very important part in propagation, flaming and extinguishing of smolder. Coupled with these thermal changes we also propose a voxel based volumetric deformation model based on springs to model smoldered fuel. To further that based on the simulation we also propose a visualization scheme that allows us to render these effects.

We hereby extend realism to combustion by introducing smoldering, oxidation effect on smolder, transition to flaming, fuel deformation and ash formation to the graphic community.