Comparing ANSYS Fluent ® and OpenFOAM ® simulations of Geldart A, B and D bubbling fluidized bed hydrodynamics

CAPOSSIO, JUAN PABLO; REYES URRUTIA, ANDRÉS; MAZZA, GERMÁN; VENIER, CESAR MARTIN; BAEYENS, JAN

INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW

EMERALD GROUP PUBLISHING LIMITED

Año: 2019

0961-5539

Purpose: The research assesses the performance of ANSYS Fluent and OpenFOAM, at their current state of development, to study the relevant bubbling fluidized bed (BFB) characteristics with Geldart A, B and D particles.Design/methodology/approach: For typical Geldart B and D particles, both a 3D cylindrical and a pseudo-2D arrangement were used to measure the bed pressure drop and solids volume fraction, the latter by digital image analysis techniques. For a typical Geldart A particle, and specifically to examine bubbling and slugging phenomena, a 2 m high 3D cylindrical arrangement of small internal diameter was used. The hydrodynamics of the experimentally investigated BFB cases were also simulated for identical geometries and operating conditions using OpenFOAM v6.0 and ANSYS Fluent v19.2 at identical mesh and numerical setups.Findings: The comparison between experimental and simulated results showed that both ANSYS Fluent and OpenFOAM provide a fair qualitative prediction of the bubble sizes and solids fraction for freely-bubbling Geldart B and D particles. For Geldart A particles, operated in a slugging mode, the qualitative predictions are again quite fair, but numerical values of relevant slug characteristics (length, velocity, frequency) slightly favor the use of OpenFOAM, despite some deviations of predicted slug velocities. Originality/value:  A useful comparison of CFD software performance for different fluidized regimes is presented. The results are discussed and recommendations are formulated for the selection of the CFD software and models involved.