Forced convection fire spread along wooden dowel array

• Published in: Fire safety journal 2021-03, Vol.120, p.103090, Article 103090
• Main Authors: Di Cristina, Giovanni, Kozhumal, Shijin, Simeoni, Albert, Skowronski, Nicholas, Rangwala, Ali, Im, Seong-kyun
• Format: Article
• Language: English
• Subjects: Anomalies; Arrays; Convection; Discrete fuels; Dowels; Flame spread; Flow velocity; Fluid dynamics; Fluid flow; Forced convection; Fuels; Hydrodynamics; Nuclear fuel elements; Wind; Wind speed; Wood combustion
• ISSN: 0379-7112; 1873-7226
• DOI: 10.1016/j.firesaf.2020.103090

The effects of freestream flow on fire spread behaviors of a discrete wooden fuel array were studied. The spacing between fuel elements was varied, and the flame spread behavior under 1, 2, and 3 m/s forced flow velocities was investigated. The fastest spread rate was not observed for the smallest spacing. Furthermore, increasing spacing did not necessarily lead to a slower spread, as seen with the flame spread along the 0.75 cm spaced array which was as fast or faster than the 0.5 cm spacing condition. At a spacing of 1 cm, fragmented flames were observed at wind speeds of 3 m/s that coincided with a slower spread rate than the 2 m/s wind conditions. The anomalies were explained using flame visualization and pitot probe measurements to determine the effects of flow speed at different spacing conditions. It seems that a coupling between the combustion and fluid dynamics of flow around the dowel cylinders under certain conditions strongly affects the fire spread behaviors. •Flame-flow interactions result in unique fragmented flames at certain flow speed and array spacing conditions.•Fragmented flames and higher flow fluctuations result in a slower fire spread at a higher wind speed.•In general, flame propagation is slightly non-linear at the tested wind speeds, in contradiction to prior models.