Sliding mesh computational fluid dynamics - a predictive tool in stirred tank design

The use of a fully predictive numerical model of flow in a stirred, baffled tank is presented and validated for the laminar flow regime. This approach employs a commercial computational fluid dynamics (CFD) package with sliding mesh facility. The comparison of computed and experimental values for various flow characteristics shows a very good agreement without the need to input any experimental values for the boundary or initial conditions. It is proposed that the model/experiment error ratio (involving relative errors) may be generally adopted as a criterion for the quality of CFD modelling. This ratio should not be much larger, and does not need to be smaller, than unity. The ratio obtained in this work was just over unity. The state of the art CFD packages are now believed to be able to form a suitable basis for the process engineering aspects of an integrated design of stirred tanks, including mechanical engineering and other related issues.