Shape evolution and bubble formation of acoustically levitated drops

Di, Wenli; Zhang, Zehui; Li, Lin; Lin, Kejun; Li, Jun; Li, Xiaoguang; Binks, Bernard P.; Chen, Xiaopeng; Zang, Duyang

Abstract

In this study, we investigated the shape evolution and bubble formation of acoustically levitated drops upon increasing the sound intensity. Here, a levitated liquid drop evolves progressively from an oblate spheroidal shape to a flattened film to a thin bowl-shaped film, eventually forming a closed bubble. Through systematic experiments, numerical simulation, and scaling analysis, we demonstrate that the buckled geometry of the liquid film can drastically enhance the suction effect of acoustic radiation pressure at its rim, forming a significant pressure gradient inside the film which causes an abrupt area expansion and bubble formation. Our results provide the mechanical origin responsible for the shape evolution and bubble formation of acoustically levitated drops, and highlight the role of buckled geometry in the levitation and manipulation of liquid films in an ultrasound field.

Citation

Di, W., Zhang, Z., Li, L., Lin, K., Li, J., Li, X., Binks, B. P., Chen, X., & Zang, D. (2018). Shape evolution and bubble formation of acoustically levitated drops. Physical Review Fluids, 3, Article 103606. https://doi.org/10.1103/PhysRevFluids.3.103606

• Journal Article Type: Article
• Acceptance Date: Oct 25, 2018
• Online Publication Date: Oct 29, 2018
• Publication Date: Oct 1, 2018
• Deposit Date: Apr 4, 2019
• Publicly Available Date: Apr 5, 2019
• Journal: Physical Review Fluids
• Print ISSN: 2469-990X
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 3
• Article Number: 103606
• DOI: https://doi.org/10.1103/PhysRevFluids.3.103606
• Keywords: Drops and bubbles; Rheology
• Public URL: https://hull-repository.worktribe.com/output/1547316
• Publisher URL: https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.3.103606
• Contract Date: Apr 5, 2019