Development of a Couette-Taylor flow device with active minimization of secondary circulation.

A novel Taylor-Couette experiment has been developed to produce rotating shear flows for the study of hydrodynamic and magnetohydrodynamic instabilities which are believed to drive angular momentum transport in astrophysical accretion disks. High speed, concentric, corotating cylinders generate the flow where the height of the cylinders is twice the radial gap width. Ekman pumping is controlled and minimized by splitting the vertical boundaries into pairs of nested, differentially rotating rings. The end rings and cylinders comprise four independently driven rotating components which provide flexibility in developing flow profiles. The working fluids of the experiment are water, a water-glycerol mix, or a liquid gallium alloy. The mechanical complexity of the apparatus and large dynamic pressures generated by high speed operation with the gallium alloy presented unique challenges. The mechanical implementation of the experiment and some representative results obtained with laser Doppler velocimetry in water are discussed.