Abstract
A new way of using thermography for radiative objects like pool flames is introduced and applied to small pool flames of three different fuels. Radiative characteristics and flame structure of small pool flames are considered by comparing flame temperature distribution from a radiation point of view. In addition, it was shown that pool flame structure of various fuels became more clear when the standard deviation and the coefficient of variation obtained from thermographic data were used. The discussion allows the following conclusions :
(1) Small pool flames tend to have a high radiance zone in the continuous flame region. This high radiance zone is important to sustain pool flames thermally.
(2) In addition to the high radiance zone of the continuous flame region, luminous flames of heptane and kerosene have an upper high radiance zone near the boundary of continuous and intermittent flame regions. When a mushroom flame cap is observed, it forms here.
(3) The non luminous flame of methanol does not have the upper high radiance zone because combustion of soot will not occur near the boundary of continuous and intermittent flame regions.
(4) The contours of standard deviation give us information about the flame edge and the vortex regions where mushroom flame cap is formed.
(5) The contours of the coefficient of variation identify the limits of the stable flame region.
