Adaptive compartment selection for the coupled simulation of population balance and fluid dynamics

The coupled simulation of crystallization and fluid dynamics is a complex multi-scale and multi-phenomena problem. An approach employing existing specialized software tools on two different grids is used for the simulation of this problem. The fluid dynamics is solved on a fine scale with FLUENT, the crystal population balance is solved in Parsival in ideally mixed compartments. The proper choice of these compartments and their runtime adaptation to match the changing profiles of the governing variables is discussed. An adaptation criterion based on the maximum deviation between the values of the governing variables in a candidate compartment is employed. An adaptation strategy which simultaneously splits and merges the compartments according to the values of the adaptation criterion is developed and used for adaptive coupled simulation of a simple cooling crystallization case study with temperature chosen as a governing variable. The results show significant reduction of the error compared with non-adapted coupled simulation. The potential of compartment adaptation and the proper choice of the governing variables in the adaptation criterion are underlined.