How to Burn? Straight vs Horizontal vs Suspended

Abstract

Burning is an inevitable process that happens in nature and has a massive impact on life. Technically, burning or combustion emphasizes on the reaction process that consumes oxidizer and fuel to deliver heat and burnt products. Based on the direction of reaction propagation and fuel orientation, burning or combustion is classified in to forward or reverse combustion. Forward combustion is a process which comprises of movement of air and the propagation of ignition zone in the same direction while in reverse combustion, air moves opposite to the direction of the propagation of the ignition zone. Forward combustion escalates rapidly in solid fuels when compared to reverse combustion. The conductivity of the burning solid fuel, convection due to the atmospheric air around and buoyancy effects which takes place due to the difference in air densities plays a major role in the forward combustion process. In this work, thin uniform cross-sectioned solid materials such as matchsticks, candles and incense sticks have been considered as fuel to investigate forward flaming and smoldering. The experiments were carried out in ambient atmospheric conditions. The results based on visualizations suggest that the orientation of the fuel has a greater impact on burning rates and provides us the information on how to burn it in a beneficial way.