Oscillatory Motion of a Droplet Cluster

Horizontal oscillations of small droplet clusters (from one to four droplets) levitating over a locally heated water layer in upward vapor–air flow are investigated experimentally. These oscillations are caused by a complex dynamic interaction between the droplets and the nonsteady gas flow. The path of the center of the droplet cluster is similar to a random walk in a potential well. The vibrational spectra of clusters’ centers obtained by Fourier analysis showed several frequency peaks between f = 1.61 and 5.96 Hz found in all clusters, which shows that the cluster tends to oscillate as a whole. The possibility of decoupling of the aerodynamic interaction between the gas flow and the droplets and the interaction between individual droplets is discussed.

[1]  E. Bormashenko,et al.  Droplet clusters: nature-inspired biological reactors and aerosols , 2019, Philosophical Transactions of the Royal Society A.

[2]  Edward Bormashenko,et al.  On relative contribution of electrostatic and aerodynamic effects to dynamics of a levitating droplet cluster , 2019, International Journal of Heat and Mass Transfer.

[3]  L. Dombrovsky,et al.  Suppression of the condensational growth of droplets of a levitating cluster using the modulation of the laser heating power , 2018, International Journal of Heat and Mass Transfer.

[4]  E. Bormashenko,et al.  Langevin Approach to Modeling of Small Levitating Ordered Droplet Clusters. , 2018, The journal of physical chemistry letters.

[5]  E. Bormashenko,et al.  Small Levitating Ordered Droplet Clusters: Stability, Symmetry, and Voronoi Entropy. , 2017, The journal of physical chemistry letters.

[6]  L. Dombrovsky,et al.  Expanding the temperature range for generation of droplet clusters over the locally heated water surface , 2017 .

[7]  Edward Bormashenko,et al.  Self-assembled levitating clusters of water droplets: pattern-formation and stability , 2017, Scientific Reports.

[8]  T. Kotsev.  Viscous Flow Around Spherical Particles in Different Arrangements , 2017 .

[9]  L. Dombrovsky,et al.  The use of infrared irradiation to stabilize levitating clusters of water droplets , 2016 .

[10]  M. Ichikawa,et al.  Dynamics of microdroplets over the surface of hot water , 2015, Scientific Reports.

[11]  A. Shavlov,et al.  Sound oscillation of dropwise cluster , 2012 .

[12]  E. Brown,et al.  A model of diffusion in a potential well for the dynamics of the large-scale circulation in turbulent Rayleigh-Bénard convection , 2008, 0807.3193.

[13]  A. Fedorets.  Droplet cluster , 2004 .

[14]  W. Sirignano.  Fluid Dynamics and Transport of Droplets and Sprays: Droplet Interactions with Turbulence and Vortical Structures , 1999 .