A multi-scale framework for CFD modelling of multi-phase complex systems based on the EMMS approach

摘要

The averaged conservative equations in CFD modeling are inadequate to achieve a complete description of the multi-scale structures in multiphase complex systems. By considering the relationship between meso-scale structures and meso-scale energy consumption, stability conditions mathematically expressed as a mutually constrained extremum are proposed in the Energy-Minimization Multi-Scale (EMMS) approach and indispensable to reflect the compromise of different dominant mechanisms for various multiphase systems. The approach is first applied to global systems to predict and physically interpret the macro-scale structure evolution, i.e., regime transition. Then when applied to computational cells, it corrects interphase momentum transfer and greatly improves the accuracy of coarse-grid CFD simulation.