(400ad) BubbleTree: A Rigorous Algorithm for Lagrangian Tracking and Statistical Analysis of Bubble or Cluster Motion within 3D Fluidized Bed Simulations

Bubbling dynamics and distribution of gas flow critically influence the performance of fluidized bed reactors and must be quantified accurately for their design and performance optimization. In this study, BubbleTree (BT) toolset is developed using python based Visualization Tool Kit (VTK) for analyzing 3D computational fluid dynamics simulation data and performing statistical analysis of bubbling dynamics. The algorithm has been rigorously validated using simulation data from pilot-scale bubbling bed simulations and, in addition to bubble properties such as their volumes, locations and velocities, this toolkit provides the capability to (a) track bubbles through coalescence and splitting events and (b) compute gas bypass (or throughflow) by integrating gas fluxes through bubble surfaces. Further, the applicability of this toolset is also demonstrated for tracking particle clusters in circulating fluidized bed simulations. BubbleTree will be integrated with MFiX CFD simulations allowing for in situ computation of bubble- (and cluster-) based physical model (e.g. sub-grid models) and enable the fundamental investigation of gas-solids flow interaction in complex reacting particulate flows.