Numerical Investigation of the Performance of a Divergent Two-Section Porous Burner for Radiant Heating

The two-section porous burner appears to be a very promising solution for radiative heating systems. In this study, the performance of a divergent porous burner for radiant heating, such as stability limit, radiative efficiency and uniformity of exit solid temperature of the burner is numerically investigated using a two-dimensional model with the volume averaged method (VAM). The results show that a significantly wider stability limit is achieved by the modeled burner compared to that of the conventional one. The uniformity of the solid temperature at the burner outlet is evaluated using a root mean square (RMS) value (T_RMS). It is demonstrated that the maximum T_RMS throughout the investigation is 32 K and the average temperature is 1702 K, showing a uniform distribution of heating temperature. However, the radiative efficiency of the modeled burner is smaller than that of the conventional one, mainly owing to the porous material applied in the downstream section. The results indicate that the modeled burner is capable of operating within a wider stability limit with uniform heating temperature. Porous media with greater emissivity in the downstream of the burner are recommended for improving radiative efficiency.