Experiments on the influence of the geometry on the stability of Taylor-Couette flow

The influence of the container geometry on the stability of the Taylor-Couette flow was investigated. The length of the annular regime was varied and thus a variable vortex size produced. For long concentric cylinders, the occurrence of traveling waves on increasing Re is dependent on the vortex size, and different wave types are observed. Short cylinders have a stabilizing effect in that higher critical Re are found. Other wave types are also produced. For a system with a square outer cylinder stable stationary vortex flows are found as well. These tend to become asymmetric, but still stationary. On further increase in Re these flows become time dependent, at first almost periodic but soon and at comparatively low Re turbulent. The velocity spectra are similar to those for other flows, however none of the popular chaos models is sufficient to describe this way to turbulence. Anomalous vortex flows are found for both geometries and their stability limits were investigated. The measurements are in qualitative agreement with the theoretical predictions of Benjamin.