Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.
Understanding the spread rate of a combustible surface is vital in estimating the fire hazards involved while handling that material. The spread rate is a function of several physical parameters, one of which is the inclination of the surface with respect to the gravity vector. Further, flame spread direction plays a significant role. For instance, upward flame spread is gravity assisted since the flame spread direction is same as the buoyancy induced flow direction and it takes place at a much faster rate when compared to the downward flame spread where gravity induced flow opposes the flame spread. Hence, there is a need to study the effect of inclination of the fuel surface with respect to gravity vector in both upward (concurrent) and downward (opposed) flame spread situations. This paper is an attempt to experimentally study the effect of angular orientation of a thin paper surface on flame spread rates. Spread rate of diffusion flame established over a thin paper having dimensions 20 mm by 300 mm, has been measured by orienting the fuel surface at various angles from -90º to 90º measured with respect to the horizontal, (0º corresponds to horizontal orientation).