| Abstract: | Diffusion is often used as the model for real diffusion phenomena, as well as the used approach for non‐diffusive phenomena, the latter due to its relative simplicity, to the existence of many mathematical tools to solve the resulting differential equations, and to its robustness if a numerical solution is to be obtained. When searching for the solution of a practical problem, the involved phenomena and processes are usually complex or/and the real phenomena is other than diffusion, and some comments need to be addressed if a diffusive model is adopted. This work concerns mainly on the author’s experience on the transport phenomena field (fluid dynamics and heat and mass transfer), including the numerical simulation of systems and processes, where the diffusive model is often used even to model non‐diffusive phenomena. It is thus a report of some ill‐answered questions that the author has experienced, related with the use of the diffusion model. Different ill‐answered questions, related with the diffusion modeling, in different fields or problems, could be equally founded. |
