Depending on the complexity of process fluid dynamics, different modeling ways can be applied, their rigor and complexity stretching over a wide range. Among these ways are a direct application of the equations of fluid dynamics, the hydrodynamic analogy method and the rate-based approach. These methods are complementary in the sense that, together, they are able to govern both simple and very complex process fluid dynamic conditions. Moreover, there is also another complementarity between the different approaches, namely, they can be applied in combination, for instance, by estimating process parameters by a more rigorous method and delivering them to the less rigorous one. In this contribution, the complementary modeling is discussed in detail and illustrated with case studies.

This paper gives a state-of-the-art review of the structured packings modeling methods, focusing on two innovative and particularly promising approaches. The first of them is based on the application of CFD, whereas the second one employs the idea of hydrodynamic analogy between complex and simple flow patterns. Both approaches are illustrated with several case studies.