Sharma, S and Pratap Singh, A and Srinivas Rao, S and Kumar, A and Basu, S (2021) Shock induced aerobreakup of a droplet. In: Journal of Fluid Mechanics, 929 .
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Abstract
The multiscale dynamics of a shock-droplet interaction is crucial in understanding the atomisation of droplets due to external airflow. The interaction phenomena are classified into wave dynamics (stage I) and droplet breakup dynamics (stage II). Stage I involves the formation of different wave structures after an incident shock impacts the droplet surface. These waves momentarily change the droplet's ambient conditions, while in later times they are mainly influenced by shock-induced airflow. Stage II involves induced airflow interaction with the droplet that leads to its deformation and breakup. Primarily, two modes of droplet breakup, i.e. shear-induced entrainment and Rayleigh-Taylor piercing (RTP) (based on the modes of surface instabilities) were observed for the studied range of Weber numbers. A criterion for the transition between two breakup modes is obtained, which successfully explains the observation of RTP mode of droplet breakup at high Weber numbers. For 1000]]>, the breakup dynamics is governed by the shear-induced surface waves. After formation, the Kelvin-Helmholtz waves travel on the droplet surface and merge to form a liquid sheet near the droplet equator. Henceforth, the liquid sheet undergoes breakup processes via nucleation of several holes. The breakup process is recurrent until the complete droplet disintegrates or external drag acting on the droplet is insufficient for further disintegration. At lower Weber numbers, the droplet undergoes complete deformation like a flattened disk, and a multibag mode of breakup based on RTP is observed. ©
| Item Type: | Journal Article |
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| Publication: | Journal of Fluid Mechanics |
| Publisher: | Cambridge University Press |
| Additional Information: | The copyright for this article belongs to Authors |
| Keywords: | Deformation; Disintegration; Dynamics; Shear flow; Surface waves, Breakup dynamics; Droplet breakup; Droplet surfaces; Drops and bubbles; Induced airflow; Rayleigh-Taylor; Shear-induced; Shock induced; Stage I; Weber numbers, Drop breakup |
| Department/Centre: | Division of Interdisciplinary Sciences > Interdisciplinary Centre for Energy Research Division of Mechanical Sciences > Mechanical Engineering |
| Date Deposited: | 03 Dec 2021 08:43 |
| Last Modified: | 03 Dec 2021 08:43 |
| URI: | http://eprints.iisc.ac.in/id/eprint/70604 |
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