报告时间：2024年01月02日10:00

报告地点：中以楼二层会议室

报告题目：Cavitation bubble interaction with hard and soft matter: from erosion to nucleation

报告人：Professor Claus-Dieter Ohl, Otto-von-Guericke University

个人简介：

Claus-Dieter Ohl教授一直致力于多相流体力学的研究，重点是空化和由此产生的流动。1998年毕业于哥廷根大学（德国）的Werner Lauterborn教授课题组，获得物理学博士学位。后在Johns Hopkins大学（Prosperetti教授）和U Twente（Lohse教授）的课题组担任了两个博士后职位，同时获得了2005年荷兰VIDI基金支持。他的研究重点是实验流体力学，特别是利用激光、冲击波和空化气泡在医学治疗、生物学和工程中的应用。 2007年，加入新加坡南洋理工大学，在NTU的10年里，他的实验室对微流体和软材料、时间反转声学、聚焦光声学和纳米流体学的空化做出了重要贡献。2017年，他被聘任为德国马格德堡大学的教授，目前的研究专注于多相复杂边界，即水凝胶中的蒸汽气泡、液滴动力学、细胞与电流和声波的相互作用以及一般空化。

报告摘要：

Non-spherical cavitation bubble dynamics in liquids are known to create enormous shear stresses which may be even enhanced when the bubbles are entrained in a flow. Yet the mechanism by which cavitation creates erosion is through shock wave focusing and not related to the jet impact or a spherical energy focusing. It is actually the opposite; erosion results from the loss of axisymmetry. Non-spherical cavitation in elastic solids generate shear waves that transport deformation energy to distances much larger than the local strain field. We will show that two shear waves with different orientation are generated near a boundary and their individual amplitude is a function of the stand-off distance. These waves can be recorded with acoustic plane wave imaging at very high frame rates. I’ll end the presentation with the deliberate nucleation of small nanobubbles and a useful application in liquids and elastic materials. 

相关论文：

1. Pfeiffer, P., Shahrooz, M., Tortora, M. Casciola, C.M., Holman, R., Salomir, R., Meloni, S., Ohl, C.D., Heterogeneous cavitation from atomically smooth liquid–liquid interfaces. Nat. Phys. 18 (2022) 1431–1435.

2. Tan, B.H., An H., Ohl C.D., Body Forces Drive the Apparent Line Tension of Sessile Droplets. Phys. Rev. Lett. 130 (2023) 064003

3. Pfeiffer, P, Eisener, J., Reese, H., Li, M., Ma, X., Sun, C., Ohl, C.D., Thermally assisted heterogeneous cavitation through gas supersaturation, Phys. Rev. Lett. 128 (2022) 194501.

4. Rossello, J.M., Ohl, C.D., On-Demand Bulk Nanobubble Generation through Pulsed Laser, Phys. Rev. Lett. 127 (2021) 044502.

5. Tan, B.H., An, H., Ohl, C.D., How Bulk Nanobubbles Might Survive, Phys. Rev. Lett., 124 (2021) 134503.

联系人：姚志峰    yzf@cau.edu.cn