Transient time-delay focusing of shock waves in thin liquids
| Autor: | Claus-Dieter Ohl, Fabio De Colle, Ulisses J. Gutiérrez-Hernández, Pedro A. Quinto-Su |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Shock wave
Physics Work (thermodynamics) Mechanical Engineering Dynamics (mechanics) Condensed Matter Physics 01 natural sciences 010305 fluids & plasmas Computational physics Superposition principle Mechanics of Materials Cavitation 0103 physical sciences Line (geometry) Transient (oscillation) 010306 general physics Focus (optics) |
| Zdroj: | Journal of Fluid Mechanics. 910 |
| ISSN: | 1469-7645 0022-1120 |
| DOI: | 10.1017/jfm.2020.1005 |
| Popis: | In this work we propose and demonstrate a Fresnel-lens-inspired method to focus multiple laser-induced shock waves through time-delay superposition at arbitrary locations. While the principle works for any geometry, we demonstrate that this method already achieves focusing with two pairs of photoacoustic shock wave emitters located on a line centred around the acoustic axis ( ns, respectively. We find that the location of constructive superposition is significantly closer to the origin than what would be expected for linear waves in homogeneous media. This is confirmed with simulations using an Euler solver that shows the importance of finite-amplitude effects. The simulated dynamics are in reasonable agreement with our measurements. Finally, pressure gains at various locations along the acoustic axis are tested with the response of gaseous microbubbles acting as pressure probes. The measurements agree with calculated pressure ratios at different positions. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|