Research on the particle scale gas and solid non-gray thermal radiation transfer

Gas radiation emission is important for particle heat transfer in combustion scenarios where gas products are radiative participating media. However, it is usually neglected in particle scale simulations, and its magnitude and variation with void fraction are unclear. A particle scale thermal radiation model is developed to investigate the radiation heat transfer mechanism between the gas and solid phase. The radiative properties are modeled by the full spectrum k-distribution method, and the radiative transfer equation is solved by the discrete ordinates method. Results show that gas and solid radiative heat fluxes are about 1300 W/m2 and 4500 W/m2 for the dense and dilute conditions respectively, and decrease exponentially with the solid volume fraction. The local environmental temperature model is evaluated and shown to significantly over-estimate the gas radiation. Variations of the radiative exchange between the gas and solid with temperature and species fractions are also simulated and analyzed. •Particle scale gas and particle non-gray radiation model is devloped.•Gas radiation to a particle decreases exponentially with particle volume fraction.•Particle radiative heat flux decreases with gas temperature.•Particle radiative heat flux increases with species molar fractions.