On the mechanics of droplet surface crater during impact on immiscible viscous liquid pool

被引:5
作者
Roy, Durbar [1 ]
Sophia, M. [1 ]
Basu, Saptarshi [1 ]
机构
[1] Indian Inst Sci, Dept Mech Engn, Bengaluru 560012, India
关键词
drops and bubbles; COUPLED OSCILLATIONS; WORTHINGTON JETS; EJECTA SHEET; BREAKUP; ENTRAPMENT; GENERATION; DYNAMICS;
D O I
10.1017/jfm.2022.1071
中图分类号
O3 [力学];
学科分类号
08 ; 0801 ;
摘要
We study drop impacts on an immiscible viscous liquid pool and investigate the formation of droplet surface craters using experimental and theoretical analyses. We attribute the formation of air craters to the rapid deceleration of the droplet due to viscous drag force. The droplet response to the external impulsive decelerating force induces oscillatory modes on the surface exposed to the air forming capillary waves that superimpose to form air craters of various shapes and sizes. We introduce a non-dimensional parameter (gamma ), that is, the ratio of the drag force to the capillary force acting on the droplet. We show that gamma is directly proportional to the capillary number. We show that droplets forming air craters of significant depths have gamma > 1. Further, we demonstrate that Legendre polynomials can locally approximate the central air crater jet profile. We also decipher that the air crater response time scale (T) varies as the square root of impact Weber number (T similar to We(1/2)). Further, we generalize the local droplet response with a global response model for low impact energies based on an eigenvalue problem. We represent the penetrating drop as a constrained Rayleigh drop problem with a dynamic contact line. The air-water interface dynamics is analysed using an inviscid droplet deformation model for small deformation amplitudes. The local and global droplet response theories conform with each other and depict that the deformation profiles could be represented as a linear superposition of eigenmodes in Legendre polynomial basis. We unearth that the droplet response in an immiscible impact system differs from the miscible impact systems due to the presence of such a dynamic contact line.
引用
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页数:30
相关论文
共 61 条
[1]  
ADRIAN RJ, 1991, ANNU REV FLUID MECH, V23, P261, DOI 10.1146/annurev.fluid.23.1.261
[2]   The Impact of Nanofluids on Droplet/Spray Cooling of a Heated Surface: A Critical Review [J].
Aksoy, Yunus Tansu ;
Zhu, Yanshen ;
Eneren, Pinar ;
Koos, Erin ;
Vetrano, Maria Rosaria .
ENERGIES, 2021, 14 (01)
[3]   Impact, recoil and splashing of molten metal droplets [J].
Aziz, SD ;
Chandra, S .
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, 2000, 43 (16) :2841-2857
[4]  
BARENBLATT G. I., 1996, SCALING SELF SIMILAR, DOI 10.1017/CBO9781107050242
[5]   Singular jets and bubbles in drop impact [J].
Bartolo, D ;
Josserand, C ;
Bonn, D .
PHYSICAL REVIEW LETTERS, 2006, 96 (12)
[6]  
Benjamin T.B., 1981, TRENDS APPL PURE MAT, VIII
[7]   Impact of a heterogeneous liquid droplet on a dry surface: Application to the pharmaceutical industry [J].
Bolleddula, D. A. ;
Berchielli, A. ;
Aliseda, A. .
ADVANCES IN COLLOID AND INTERFACE SCIENCE, 2010, 159 (02) :144-159
[8]   Stability of Constrained Capillary Surfaces [J].
Bostwick, J. B. ;
Steen, P. H. .
ANNUAL REVIEW OF FLUID MECHANICS, VOL 47, 2015, 47 :539-568
[9]   Dynamics of sessile drops. Part 1. Inviscid theory [J].
Bostwick, J. B. ;
Steen, P. H. .
JOURNAL OF FLUID MECHANICS, 2014, 760 :5-38
[10]   Coupled oscillations of deformable spherical-cap droplets. Part 2. Viscous motions [J].
Bostwick, J. B. ;
Steen, P. H. .
JOURNAL OF FLUID MECHANICS, 2013, 714 :336-360