摘要： We experimentally demonstrate self-excited oscillation and shedding of millimeter-sized water drops, acoustically levitated in a single-node standing waves cavity, by decreasing the steady acoustic wave intensity below a threshold. The perturbation of the acoustic field by drop motion is a possible source for providing an effective negative damping for sustaining the growing amplitude of the self-excited motion. Its further interplay with surface tension, drop inertia, gravity and acoustic intensities, select various self-excited modes for different size of drops and acoustic intensity. The large drop exhibits quasiperiodic motion from a vertical mode and a zonal mode with growing coupling, as oscillation amplitudes grow, until falling on the floor. For small drops, chaotic oscillations constituted by several broadened sectorial modes and corresponding zonal modes are self-excited. The growing oscillation amplitude leads to droplet shedding from the edges of highly stretched lobes, where surface tension no longer holds the rapid expanding flow. 其他題名： Phys Rev E 出版者： United States 出版日期： 2016-02 出處： Physical review. E, 2016-02, Vol.93 (2), p.021101, Article 021101 識別號： ISSN: 2470-0045 識別號： ISSN: 2470-0053 識別號： EISSN: 2470-0053 識別號： DOI: 10.1103/PhysRevE.93.021101 識別號： PMID: 26986279
