Local Complexities and Global Spatio-temporal Patterns in Large Arrays of Fluid-elastic Oscillators (From Vibrating Pipes in Heat Exchangers to Waving Plants in Agricultural Fields)

摘要

We have performed experiments on spatio-temporal pattern formation ma large array of nonlinear oscillators with many degrees of freedom Our model experiments have used a group of vertically cantilevered elastic rods densely arranged on a two-dimensional lattice in a uniform cross-flow. Our previous presentations have reported success in observing hierarchical spatio-temporal pattern formations such as solo rods, rod clusters, and wave motion of cluster-chains m experiments. Simple experiments using an elastic-rod array are performed in the wind tunnel. Despite their simplicity, such experiments allow observation of a variety of complex dynamical phenomena in such conditions. In addition the beautiful dynamic structure underlying complex behaviors can be explained in detail. Commonly in the study of complex systems, parameter changes reveal novel relationships among elements. Such relationships emphasize the self-organization of hierarchical dynamic structures. It is noteworthy that the existence of identical phenomena can be confirmed in the mechanical engineering field. Moreover, experimental results may be applicable to advanced design of planted trees for protection against wind in the fields of civil engineering, forestry, and agriculture.