Shape evolution of a melting nonspherical particle

Abstract

In this study melting of irregular ice crystals was observed in an acoustic levitator. The evolution of the particle shape is captured using a high-speed video system. Several typical phenomena have been discovered: change of the particle shape, appearance of a capillary flow of the melted liquid on the particle surface leading to liquid collection at the particle midsection (where the interface curvature is smallest), and appearance of sharp cusps at the particle tips. No such phenomena can be observed during melting of spherical particles. An approximate theoretical model is developed which accounts for the main physical phenomena associated with melting of an irregular particle. The agreement between the theoretical predictions for the melting time, for the evolution of the particle shape, and the corresponding experimental data is rather good.

Simulation of W‐band radar reflectivity for model validation and data assimilation

“…It must be borne in mind that the melting snow flakes undergo structural changes (i.e. shape) during the melting process (Mitra et al , ; Kintea et al , ). Therefore, we have less confidence in forward modelling the melting layer than the cold and warm phases.…”

Reorganization of a granular medium around a localized transformation

“…For instance, dilatations of the material and phase transitions affect the volume of the particles [1,2]. Consequently, the shapes of particles are modified [3] as well as their flowing properties through a lubrication film [4] or the formation of capillary bridges [5]. In addition, chemical reactions can also modify the surface and nature of each individual grain [6].…”

Experimental and numerical investigations of snow accretion.

“…1 presents samples of ice crystals (columns, columns with plates, plates in the top row, planar dendrites in the third row, graupel (or snow pellets) in the fifth row) and snowflakes with different degrees of riming in the three last rows. This point was not addressed by the European projects HAIC [4] and [5], where the models for trajectory, impact and erosion [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] were derived for ice particles with higher densities and more regular geometric shapes. In the framework of these two previous projects [4,5], models for mixed phase and ice crystal icing (Appendix D) have been derived from academic [10,16] and more applied experiments [11,15] to be integrated into numerical tools able to simulate the entire accretion process [14].…”