How does increasing the surface-to-mass ratio of a solid fuel affect its ignition time and initial fire growth rate?

Increasing the surface-to-mass ratio of a solid fuel significantly reduces its ignition time and accelerates its initial fire growth rate. The surface-to-mass ratio, also known as specific surface area, quantifies the amount of surface area exposed per unit of mass of a solid fuel. For example, fine sawdust has a much higher surface-to-mass ratio than a solid block of wood of the same material and total mass. This ratio dictates how efficiently the fuel can interact with its environment, particularly regarding heat transfer and oxygen access. Ignition time is the duration required for a material to reach a sufficient temperature and produce enough flammable gases to sustain combustion when exposed to an ignition source. For a solid fu....