The flow pattern created by a pitched blade turbine was calculated usi
ng a sliding I mesh method for various Reynolds numbers, mostly in the
laminar regime. This method allows flow pattern calculations without
the use of any experimental boundary conditions. The results compared
favourably with experimental data obtained by laser-Doppler velocimetr
y. At low Reynolds number, the impeller creates a radial flow pattern
rather than axial and the pumping number decreases with decreasing Rey
nolds number. It is concluded that the sliding mesh method is suitable
for the prediction of flow patterns in stirred tanks.