New observations on hysteresis effects in Taylor–Couette flow

In this experimental study, laser-velocimetry has been used to investigate hysteresis phenomena presented by steady flows of a viscous fluid. Dealing with Taylor–Couette flow between concentric cylinders with differential rotation, the experiments were focused on the change-over between steady states featuring four and six cells as the length of the annular domain is varied continuously. The observations are in broad qualitative agreement with the predictions of abstract mathematical models, but they display new features which appear to be beyond the scope of any quantitative theoretical results yet available.