Modeling Dust-Density Wave Fields as a System of Coupled van der Pol Oscillators

Dust-density wave fields in radio-frequency discharges under microgravity conditions exhibit complex spatiotemporal patterns. One of the most remarkable features, which reflects this behavior, is the occurrence of so-called frequency clusters, i.e., a stepwise spatial variation of the frequency inside the wave field. These frequencies were found to be incommensurable to each other. Such topological phenomena can be emulated by networks of locally coupled van der Pol oscillators. However, recent investigations showed that, in some situations, clusters with commensurable frequencies are preferred. The previously suggested model cannot explain such a preference. Hence, in this contribution, an extension of the existing model is proposed that, in addition to the local coupling, includes a global coupling mechanism.