Entry and penetration of a superhydrophobic sphere into a deep pool
Fuente:
arXiv
Salvato in:
| Autori principali: | , , |
|---|---|
| Natura: | Preprint |
| Pubblicazione: |
2025
|
| Soggetti: | |
| Accesso online: | |
| Tags: |
Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
|
| _version_ | 1866909770493984768 |
|---|---|
| author | Billa, Prasanna Kumar Tropea, Cameron Mahapatra, Pallab Sinha |
| author_facet | Billa, Prasanna Kumar Tropea, Cameron Mahapatra, Pallab Sinha |
| contents | This study experimentally examines the entry and penetration of a superhydrophobic sphere into a quiescent deep pool, with special emphasis placed on the primary and secondary pinch-off of the air cavity existing in its wake. Two aspects are novel in this study. For one, the experiments are performed for a large range of dimensionless sphere densities, where lighter spheres, with their air cavity, exhibit a terminally ascending trajectory and heavier spheres a terminally descending trajectory. The second novel result is a strong correlation of primary and secondary pinch-off times with the Froude number at impact and the dimensionless density. A semi-empirical correlation for the air cavity volume following the primary pinch-off shows excellent agreement with measurements over all dimensionless densities. A scalar force balance predicts a drastic decrease of buoyancy upon pinch-off, reflected also in the abrupt change of deceleration, measured using two orthogonally placed high-speed cameras to capture the time resolved trajectory of the sphere in the pool. Comparisons are drawn between the trajectories of superhydrophobic spheres and those of hydrophilic spheres, measured in a previous study. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2509_03928 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Entry and penetration of a superhydrophobic sphere into a deep pool Billa, Prasanna Kumar Tropea, Cameron Mahapatra, Pallab Sinha Fluid Dynamics This study experimentally examines the entry and penetration of a superhydrophobic sphere into a quiescent deep pool, with special emphasis placed on the primary and secondary pinch-off of the air cavity existing in its wake. Two aspects are novel in this study. For one, the experiments are performed for a large range of dimensionless sphere densities, where lighter spheres, with their air cavity, exhibit a terminally ascending trajectory and heavier spheres a terminally descending trajectory. The second novel result is a strong correlation of primary and secondary pinch-off times with the Froude number at impact and the dimensionless density. A semi-empirical correlation for the air cavity volume following the primary pinch-off shows excellent agreement with measurements over all dimensionless densities. A scalar force balance predicts a drastic decrease of buoyancy upon pinch-off, reflected also in the abrupt change of deceleration, measured using two orthogonally placed high-speed cameras to capture the time resolved trajectory of the sphere in the pool. Comparisons are drawn between the trajectories of superhydrophobic spheres and those of hydrophilic spheres, measured in a previous study. |
| title | Entry and penetration of a superhydrophobic sphere into a deep pool |
| topic | Fluid Dynamics |
| url | https://arxiv.org/abs/2509.03928 |