奈米工程與微系統研究所　書報討論

Seminar of Inst. NanoEngineering and MicroSystems

 Chun-Ti Cheng

Department of Mechanical Engineering

National Taiwan University

Assistant Professor

Footprint geometry and sessile drop resonance

Abstract:

This talk presents the resonance of drops under different footprint constraints on a flat plate. In experiments, we manipulate the equilibrium shapes of our sessile drops by constraining their footprints into circles (circular drops) and squares (square drops). As we probe their resonance dynamics, two families of modal behaviors are observed. One family is identified with spherical harmonics, denoted as "spherical modes." The other family is associated with Faraday waves on a square liquid bath (square Faraday waves), denoted as "grid modes." The two families are distinguished based on their dispersion behaviors. By comparing the occurrence of the modes, we recognize spherical modes as the characteristic of sessile drops, and grid modes as the constrained response. Within a broader context, we further discuss the resonance modes of circular sessile drops and free spherical drops, and we recognize various modal behaviors as surface waves under different extents of constraint. From these, we conclude that sessile drops resonate according to how wave-number selection by footprint geometry and capillarity compete. For square drops, a dominant effect of footprint constraint leads to grid modes; otherwise, the drops exhibit spherical modes, the characteristic of sessile drops on flat plates.

15:30-17:20 on Sep. 25 (Mon), 2017 at Room 108 of Eng. Building I

Host：Prof. Chao-An Lin calin@pme.nthu.edu.tw Ext:42607

Contact：Praveen praveenbowler@gmail.com  Mobile: 0909537757