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Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Engineering / Faculty of Engineering >
Peer-reviewed Journal Articles, etc >
Free-surface flows under impacting droplets
| Title: | Free-surface flows under impacting droplets |
| Authors: | Watanabe, Yasunori Browse this author →KAKEN DB | | Saruwatari, Ayunii Browse this author | | Ingram, David M. Browse this author |
| Keywords: | droplet impact | | vortex ring | | free-surface boundary condition | | level-set method |
| Issue Date: | 1-Feb-2008 |
| Publisher: | Academic Press |
| Journal Title: | Journal of Computational Physics |
| Volume: | 227 |
| Issue: | 4 |
| Start Page: | 2344 |
| End Page: | 2365 |
| Publisher DOI: | 10.1016/j.jcp.2007.10.020 |
| Abstract: | A numerical method which fulfils the free-surface boundary conditions and extrapolates the fluid velocity in to empty grid cells outside the fluid region on a fixed Cartesian grid system is presented. The complex, three-dimensional, vortex structures formed via surface/vortex interaction and induction between vortices have been computed using the proposed technique implemented within a level-set method for both vertical and oblique droplet impacts in incompressible fluids. The present results have been validated through numerical tests which confirm zero tangential shear at the free-surface and comparisons with experimental observations of cavity and vortex ring formation underneath the impact location. In some cases, transitions from a concentric vortex ring to a fully three-dimensional vortex structure has been confirmed. Whilst the primary vortex ring is initiated at the highly curved contact surface between the droplet and receiving surface, azimuthal instabilities are manifested in the shear layer around the cavity crater developing after the vertical impact, resulting in axial counter-rotating vorticity between the cavity and descending vortex ring. Underlying mechanisms which induce local deformation of the free-surface, creating a so-called scar, due to the sub-surface vortices at the oblique impacts are also discussed. |
| Relation: | http://www.sciencedirect.com/science/journal/00219991 |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/33768 |
| Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 渡部 靖憲
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