DOI: 10.1615/TSFP7
TURBULENCE EFFECT ON RADIATIVE TRANSFER IN CLOUDS
ABSTRACT
The effect of turbulent clustering of water droplets on radiative transfer is investigated by means of a three-dimensional direct numerical simulation (DNS) for particle-laden homogeneous isotropic turbulence and a radiative transfer simulation based on a Monte Carlo photon tracing method. Two kinds of radiations, namely visible and infrared radiations are considered. The former is not absorbed by droplets, while the latter is partially absorbed. The results show that the turbulent clustering does not influence the total transmittance of visible radiation, while it increases the total transmittance of infrared radiation. This is because the clustering of droplets allows more photons to pass through without being scattered than the random dispersion of droplets. The effect of clustering on radiative transfer decreases as the turbulent Reynolds number increases, and as the Stokes number decreases.