TRAIL part 2: A comprehensive assessment of ice particle fall speed parametrisations

McCorquodale, M. W.; Westbrook, C. D.

Abstract

Results are presented from a comprehensive experimental campaign studying the aerodynamics of 3D-printed analogues of ice particles. Measurements of the drag coefficient of the analogues were acquired by using a novel experimental approach to digitally reconstruct the analogues' trajectory and orientation as they fall through a quiescent viscous liquid, using images acquired by a series of digital cameras. The data are used to evaluate commonly used parametrisations of ice particle fall speeds. We find that the accuracy of each of the parametrisations reduces at Reynolds numbers greater than approximately 100, as a result of effects associated with the onset of unsteady oscillating, fluttering or tumbling motions as the analogues fall. We propose a new fall speed parametrisation that predicts the measured drag coefficients at high Reynolds number with an accuracy consistent with that of the leading parametrisation at low Reynolds number.

Citation

McCorquodale, M. W., & Westbrook, C. D. (2020). TRAIL part 2: A comprehensive assessment of ice particle fall speed parametrisations. Quarterly Journal of the Royal Meteorological Society, 147(734), 605-626. https://doi.org/10.1002/qj.3936

• Journal Article Type: Article
• Acceptance Date: Oct 6, 2020
• Online Publication Date: Nov 2, 2020
• Publication Date: Nov 2, 2020
• Deposit Date: Nov 11, 2020
• Publicly Available Date: Nov 11, 2020
• Journal: Quarterly Journal of the Royal Meteorological Society
• Print ISSN: 0035-9009
• Electronic ISSN: 1477-870X
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 147
• Issue: 734
• Pages: 605-626
• DOI: https://doi.org/10.1002/qj.3936
• Keywords: atmosphere, geophysical fluid dynamics laboratory experiments, ice, microphysics, snow, turbulence
• Public URL: https://nottingham-repository.worktribe.com/output/5034742
• Publisher URL: https://rmets.onlinelibrary.wiley.com/doi/10.1002/qj.3936