In ref. 1 an extensive review was made of the panel flutter problem and analyses dealing with flutter of cylindrical shells of finite length were discussed in considerable detail. It was stated that one of the central points of controversy is in the choice of the appropriately simplified governing equations for the thin–walled elastic shell. Related to this is the choice of flutter mode and the question as to how the critical flutter speed depends upon the number of circumferential and axial waves in that mode.

Stepanov and Strack and Holt found that the critical Mach number decreases with increasing number of circumferential waves, and Fung has concluded that the axially symmetric mode is of the greatest interest.

The purpose of this note is to present a relatively simple analysis in which only axi–symmetric deformations of the shell are considered. The shell is assumed to be unreinforced longitudinally.