Computer simulation of real experiment by Monte Carlo techniques has been extended to include the study of particulate fluxes in divergent conical Knudsen cell orifices. The effects of specular reflection and surface diffusion have been considered, in terms of the cone angle and length-to-radius ratio of the orifice. Large statistical sample sizes resulted in precise steady-state values for transmission coefficients, spatial distributions of effusate, and evaporation flux gradients. The results of other studies have been analyzed and interpreted in light of the Monte Carlo data.