Stirred tank simulation using Partially-Averaged Navier-Stokes k_u-epsilon _u turbulence model

Abstract

In the present study, simulation of a stirred tank using axial flow impeller has been studied numerically to see the behaviour of flow variables in the entire vessel. It is assumed that the flow is steady state, two dimensional, incompressible and axisymmetric. For simulation, Partially-Averaged Navier-Stokes (PANS) k_u-epsilon _u turbulence model has been taken into account. For discretization, control volume method along with upwind and power-law schemes have been taken. The solutions are obtained by using the SIMPLE algorithm. The boundary conditions for impeller are given by using the experimental data. The main objective is to investigate the influence of different filters width f_k of the PANS k_u-epsilon _u model parameter on the characteristic flow variables. The predicted results of the PANS k_u-epsilon _u model for different f_k have been compared with the experimental data at different axial levels of the stirred tank. It has been observed that the power-law scheme gives better agreement with the experimental data. Further, near the impeller region, PANS predicted results are better for smaller f_k. Also, Reynolds-Averaged Navier-Stokes Shear Stress Transport (SST) k-omega turbulence model has been tested for comparative study.