An Ignition characteristics of a vertical solid fuel plate with internal block has been quantitatively investigated by experimental study. In low radiant heat flux, ignition does not occur in a vertical solid fuel plate without block. In the case with the block on a vertical fuel plate, ignition can be occurred by lengthening the residence time and the time to absorb the incident radiation flux by fuel vapor in gas phase. The ignition occurs below block and the point varies by the block location and height. The ignition delay time decreases as the block height is increased, the block is located at higher position, and the hot wall temperature is increased. And as the initial temperature of fuel plate rises, the ignition delay time of the solid fuel plate decreases.
The temperature distribution of solid fuel plate with block is nearly proportional to the radiant heat flux distribution, therefore the effect of natural convection heat transfer and that of pyrolysis cancels each other.
For the solid fuel in the confined rectangular enclosure, the ignition point is governed by the hot wall temperature. If the temperature is the same, the ignition point remains the same point irrespective of the presence and location of block. For the case with block, the direction of the flame propagation is different from the case without block. When the block is located in the middle of the solid fuel plate, ignition occurs at the upper part of hot wall and the flame propagates toward fuel surface along ceiling surface. The block height increases, the lager amount of flame propagates along the ceiling surface.
