Some issues concerning fluid-elastic instability of a group of circular cylinders in cross-flow

Since the early 1970s, extensive studies of fluid-elastic instability of circular cylinders in crossflow have been reported. A significant understanding of the phenomena involved now exists. However, some confusion, misunderstanding, and misinterpretation still remain. The objective of this report is to discuss, on the basis of the current state of the art, a series of the most asked questions. Emphasis is placed on the determination of the critical flow velocity, non-dimensional parameters, stability criteria, and instability mechanisms.