Abstract
Experiments studying on the transition of the flow between concentric cylinders with the inner cylinder rotating and the outer one at rest have been made by means of flow visualization. In this study, an inner conical mirror has been used to observe the overall flow pattern at all times. Attention is focused on the effect of aspect ratio on flow regime and modulation. It has been found that the number of travelling azimuthal waves increases and modulation occurs at lower Reynolds number region with a decrease in the aspect ratio.
