Effect of Particle Size Distribution on Radiative Heat Transfer in High-Temperature Homogeneous Gas-Particle Mixtures

The weighted-sum-of-gray-gas(WSGG)model and Mie theory are applied to study the influents of particle size on the radiative transfer in high temperature homogeneous gas-particle mixtures,such as the flame in aero-engine combustor.The radiative transfer equation is solved by the finite volume method.The particle size is assumed to obey uniform distribution and logarithmic normal(L-N)distribution,respectively.Results reveal that when particle size obeys uniform distribution,increasing particle size with total particle volume fraction fvunchanged will result in the decreasing of the absolute value of radiative heat transfer properties,and the effect of ignoring particle scattering will also be weakened.Opposite conclusions can be obtained when total particle number concentration N0 is unchanged.Moreover,if particle size obeys L-N distribution,increasing the narrowness indexσor decreasing the characteristic diameter Dˉwith the total particle volume fraction fvunchanged will increase the absolute value of radiative heat transfer properties.With total particle number concentration N0 unchanged,opposite conclusions for radiative heat source and incident radiation terms can be obtained except for radiative heat flux term.As a whole,the effects of particle size on the radiative heat transfer in the high-temperature homogeneous gas-particle mixtures are complicated,and the particle scattering cannot be ignoring just according to the particle size.