Figure 9.
The dispersion curves for cylinders placed in a rectangular array are shown for Bloch waves in the x1-direction. The lowest three dispersion branches, as solid lines, and Ω=κ as dotted, are shown in (a), (b) and (c) for rectangle heights of 2, 6 and 30, respectively, where the cylinder radius is 0.95. (d) Shows the dispersion curves for a cell of height 30, in solid the second modes for the respective radii of 0.4 and 0.95 and the light-line in dashed. (e) Shows the variation of standing wave frequencies for the symmetric (solid) and antisymmetric (dashed) modes versus cylinder radius for the infinite strip.