Monte Carlo Simulation of Radiative Heat Transfer in Coarse Fibrous Media

Direct Geometric Monte Carlo modeling of a fibrous medium is undertaken. The medium is represented as a monodisperse array, with known solidity, of randomly oriented cylinders of known index of refraction. This technique has the advantage that further radiative properties of the medium (absorption coefficient, scattering albedo, scattering phase function) are not required, and the drawback that its’ Snell- and Fresnel-generated dynamics suggest a limitation to large, smooth fibers. It is found that radiative heat flux results are highly dependent on bias in the polar orientation angle (relative to the boundary planes) of the fibers. Randomly oriented fiber results compare well to both the large (specular radiosity method) and small (radiative transfer equation) limits, while the results of previous experiments lie within the range of simulation results generated using varying degrees of orientation bias.