Extensive validation of computed laminar flow in a stirred tank with threeRushton turbines

High-resolution CFD results, supplemented by extensive experimental validat ion, are presented for Newtonian laminar flow fields in a stirred tank equi pped with three Rushton turbines. Flow fields are computed using the ORCA s oftware suite for Reynolds numbers ranging from 20 to 200 with an unstructu red tetrahedral mesh containing roughly 2 million tetrahedra. Each of the f low solutions takes less than 8 h to converge when running in parallel on e ight desktop workstations. Excellent agreement is obtained between computed velocity fields and planar velocity vectors obtained using particle image velocimetry. Planar laser-induced fluorescence was used to expose persisten t poor-mixing regions, in excellent agreement with numerical results. The c omputational results used illustrate strong flow compartmentalization and s ignificant spatial heterogeneity with respect to local deformation rates wi thin the vessel.