Flow simulations in a stirred tank reactor

Stirred tank reactors (STR) are important devices used in chemical plants, and their optimal design can enhance the overall performance of the complete installation considerably. According to their application, optimization concerns mostly mixing time, in order to reduce reactant segregation, but power consumption is sometimes also important. In many cases, optimal configurations can only be obtained after a series of scale-up experiments. Computational fluid dynamics is expected to offer a cheap and less time-consuming alternative to such experiments, but appropriate methods treating complicated turbulent flows and multiple chemical reactions are not available yet. However, some applications involving laminar mixing (like mixing of liquids with high viscosity, such as plastics) can already be treated numerically. In this work, laminar flow simulations in a simplified stirred tank reactor have been carried out, and results obtained with two different numerical methods are compared.