Abstract
The viscous pump, which has a rotor with helical rectangular channels, is studied experimentally. Eight types of torsion of the channel are made to investigate the torsion effect on the flow characteristics. We measure the flux through the channel at a constant rotor speed by changing the pressures at the entrance and exit of the pump. We also observe the secondary flow at a cross-section of the channel. Some of the results obtained are shown as follows: The pressure gradient along the channel to get the same flux is large for large channel torsion at a constant rotation, and becomes small when the favorable rotation of the rotor to the flow is applied. As for the secondary flow at a cross-section, there appear several types of vortex. When there is no rotation, the secondary flow is almost symmetric two-vortex type for small flux as is the ordinary Dean vortex, but it changes to a four-vortex type when the flux is large. The secondary flow becomes asymmetric as the rotation increases. We have unsteady flow patterns at large flux and rotation.
