Multiphase CFD Modelling: State-of-the-art applications in Energy related Industrial Applications

Two-phase flows occur in many industrial processes. Reliable predictions on flow characteristics are necessary for the design, process optimization and safety analysis of related apparatuses and processes. Experimental investigations are expensive and in most cases not transferable to modified geometries or different scales and flow conditions. For this reason there is a clear requirement for numerical tools. Due to the 3D nature of flows and the importance of turbulence in most cases this means a strong need for reliable 3D CFD-tools rather than 1D system codes or simplified correlations. The general aim is to provide simulation tools for the design, optimization and safety analyses of medium and large scale applications in which multiphase flows are involved. Such tools can contribute to improve the efficient use of energy and resources (e.g. in chemical engineering and oil industries) and to guarantee the safe operation (especially nuclear safety) – provided that they are predictive. Since large scale applications are considered such as chemical reactors or components of the cooling system of a nuclear power plant the Euler-Euler two- or multi fluid model is the base for the development. Presently the predictive capabilities for basic hydrodynamics are restricted due to limitations of the closure models. For this reason one focus of our multiphase flow research is the improvement of the closures first for adiabatic flow modelling but also phase transfer, chemical reactions etc. have to be considered. A second focus is to establish modelling frameworks as iMUSIG, AIAD and GENTOP to allow a proper consideration of the local physical phenomena. These activities will help to improve the CFD code capabilities in energy related industrial applications.