Determination of local radiative properties in coal-fired flames. Technical progress report, September 16, 1989--March 15, 1990

Our primary goal in this research is to determine the effective radiative properties of pulverized coal particles in situ. These effective properties can be obtained from a detailed, interactive experimental/analytical procedure. First, a series of experiments are performed, and the attenuation and scattering of incident radiation at several angular orientations are recorded. The physical and optical characteristics of the total particle cloud determines the amount of attenuation, and this information is included in the measured projection data. Effective properties can be determined by solving the inverse radiation problem in a corresponding geometry using these projection intensity data as input. Following this, empirical relations for ``effective radiative properties`` can be derived for given physical conditions. This can be achieved if other physical properties, such as volume fraction and particle size distribution, temperature of the particles and combustion gases, and concentration distribution of gam can be predicted from theory or measured in parallel experiments, and their contributions to the experimental data are quantified. During the period covered by this report, we concentrated our efforts to measure the effective radiative properties of cold coal particles. For this purpose, we used a test cell to obtain a one-dimensional slab of coal particles. The inverse radiation models required for data reduction have been developed previously, and the details have been given in previous report`s