Published online by Cambridge University Press: 29 March 2006
Previous experiments on a small-scale rectangular water-channel with slotted walls revealed that under certain circumstances the flow could become unsteady. Although these oscillations were suppressed at the time, the mechanism of the instability was not fully understood. Theoretical work, on a similar form of instability in a circular slotted-wall wind tunnel, has been extended to describe the oscillations in the water channel. Further experiments have been performed, and in some of these the length of the outer chamber surrounding the working section was altered. Good agreement between the theoretical and experimental results was obtained. Consideration has also been given to the occurrence of the self-induced oscillations in flumes of different scale and form.