Velocity and number density profiles of particles across upward and downward flame propagating through iron particle clouds

Behaviors of particles across upward and downward flame propagating through iron particle clouds have been recorded on photomicrographs by using a high-speed video camera with a microscopic optical system. The velocity profiles of iron particles across flames were measured by using the high-speed photomicrographs, and the number density profiles of iron particles near the flames were calculated by using the velocity profiles. It is shown that the number density of iron particles changes in the range of x smaller than 11.0 mm, where x is the distance from the leading edge of the combustion zone. The number density increases with the decrease of x in the range 010.0 mm), however, for downward propagating flame, it is only 2.3 times larger than that at the region far ahead of the flame.