Applying the Galerkin Least Squares Finite Element Method for Solving Stirred Tank Velocity Fields

The Galerkin Least Squares finite element solver, in conjunction with the Spalart-Allmaras turbulence closure model, is used to solve the RANS based equations for flow fields in stirred tank reactors. This GLS finite element method is well established in the aerospace industry and presently is being validated for flow fields used in industrial processes that are commonly found in the pharmaceutical, chemical, food, and personal products industries. The CFD results, computed in the commercial package ORCA, compared well with experimental data attained for the dominating macro flow structures in an axial and radial impeller stirred tanks. The CFD quantitatively predicts the two and three-dimensional wall jet structures that govern the bulk flow in a stirred tank and are responsible for blending, solid suspension, and macro-flow. This area of experimentation provides an initial basis for CFD validation for bulk flows in stirred tank reactors.