Estimation of Thermal Emission From Mixture of CO₂ and H₂O Gases and Fly-Ash Particles

In the present work, the thermal emission from gases and particle mixture is studied comprehensively. The mixture consists of $CO2$ and $H2O$ gases along with fly-ash particles, and their spectral radiative properties are obtained from HITEMP-2010 database and Mie theory, respectively. The line-by-line (LBL) method, known for high accuracy, is used to estimate radiative heat transfer from gases and particle mixture. Three distinct cases, i.e., pure absorption/emission, pure scattering, and their combined effects, are investigated. The spectral radiative transfer equation is solved by finite angle method (FAM), and the correctness of the results is ensured by principle of energy conservation. The anisotropic scattering is modeled using the Henyey–Greenstein method. The influence of radiative properties of the participating medium, along with wall and cavity temperatures, on heat transfer and emission spectrum is evaluated. The radiative heat transfer enhances with introduction of the particles in the gaseous mixture. For pure scattering medium, the emission spectrum on each wall differs and also varies from the emission spectrum of the emitting wall. The particle influence grows notably with higher volume fractions in gaseous mixture. While there is a notable contribution of anisotropic scattering in a purely scattering medium, its significance diminishes in an absorbing, emitting, and scattering medium.