Premium
Using 3‐D‐printed analogues to investigate the fall speeds and orientations of complex ice particles
Author(s) -
Westbrook C. D.,
Sephton E. K.
Publication year - 2017
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2017gl074130
Subject(s) - falling (accident) , particle (ecology) , terminal velocity , ice crystals , materials science , reynolds number , hexagonal crystal system , mechanics , mineralogy , meteorology , geology , physics , crystallography , chemistry , environmental health , medicine , oceanography , turbulence
The terminal velocity v t and preferred orientations of ice particles have been investigated using 3‐D‐printed analogues sedimenting in glycerine solutions at Reynolds numbers typical of natural ice particles falling in air. Twenty‐two different particle geometries were investigated: these included both simple shapes, such as hexagonal plates, and more complex particles, such as bullet rosettes, plate polycrystals, and aggregates. Two widely used prescriptions for ice particle fall speed were tested against the new experimental data, to determine the accuracy of their predictions. We show that for open particles, such as bullet rosettes and aggregates, one of these prescriptions systematically overestimates v t , by as much as 80%.