Contribution to the modelling of the ice accretion process : ice density variation with the impacted surface angle

International audience Icing measurements were carried out in natural winter clouds with an instrumented wind tunnel set up at the summit of Puy de Dame (1 500 m a.s.1.). The microphysical data (liquid water content, drop-let spectra) were obtained by using the particle measuring system PMS ASSP 100...

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Bibliographic Details
Published in:Annals of Glaciology
Main Authors: Bain, M, Gayet, J. F.
Other Authors: Université Blaise Pascal - Clermont-Ferrand 2 (UBP)
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 1983
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Online Access:https://hal.uca.fr/hal-01962487
https://hal.uca.fr/hal-01962487/document
https://hal.uca.fr/hal-01962487/file/igs_annals_vol04_year1983_pg19-23.pdf
https://doi.org/10.3189/S0260305500005176
Description
Summary:International audience Icing measurements were carried out in natural winter clouds with an instrumented wind tunnel set up at the summit of Puy de Dame (1 500 m a.s.1.). The microphysical data (liquid water content, drop-let spectra) were obtained by using the particle measuring system PMS ASSP 100. The ice density was measured on a rotating cylinder and the ice deposit of the cross-section was photographed on a fixed cylinder. The density measurements ranged from 300 to 900 kg m-3 during the experiment and are in agreement with Macklin's results (1962). The profile of the ice deposit is compared to the profile predicted by the model of Lozowski and others (1979), which considers a fixed density. ~Ie propose to improve this model by taking into account the variation of ice density with the angle of impact on the cylinder. This calculation is based on Macklin's results and on the determination of the 1 oca I impact speed by us i ng the result of La ngmu i r and Blodgett (1960). The variation of ice density with the angle depends on various parameters: pressure, temperature, air speed, liquid water content, and, especially, the droplet distribution. The improvement is not sufficient to explain some observed profiles; this may be attributed to the fact that the model is not time-dependent.