Abstract
The fourth order central finite difference scheme is applied to the convection terms in three-dimensional Navier-Stokes equations to simulate directly the flow fields in a medium Reynolds number baffled stirred tank. The rotational cylindrical coordinates with angular velocities are used to express boundary conditions on impellers. On the other hand the stationary cylindrical coordinates are adopted for baffles. When the fluid is water, the phenomena during 60 seconds, which are the sufficient time for obtaining various flow mechanisms and time averaged flow characteristics in a stirred tank, are simulated using this calculation method. The calculated results are in good agreement with the measured data. Then, this study makes a way for direct numerical simulations of various type stirred tank with various type impellers and baffles.
