Abstract
| Original language | English |
|---|---|
| Pages (from-to) | 133-137 |
| Journal | Cold Regions Science and Technology |
| Volume | 151 |
| DOIs | |
| Publication status | Published - Jul 2018 |
| MoE publication type | A1 Journal article-refereed |
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Keywords
- ice accretion
- rime ice
- collision efficiency
- history term
- droplet distribution
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Modelling the growth of large rime ice accretions. / Makkonen, Lasse; Jian, Zhang; Karlsson, Timo; Tiihonen, Mikko.
In: Cold Regions Science and Technology, Vol. 151, 07.2018, p. 133-137.Research output: Contribution to journal › Article › Scientific › peer-review
TY - JOUR
T1 - Modelling the growth of large rime ice accretions
AU - Makkonen, Lasse
AU - Jian, Zhang
AU - Karlsson, Timo
AU - Tiihonen, Mikko
PY - 2018/7
Y1 - 2018/7
N2 - The conventional theory of droplet collision with an object can be used only down to a collision efficiency of about 0.1. Therefore, no accurate modelling of in-cloud icing has been possible when droplets are small, wind speed is low, or the object is large. This has also put a limit on the size of an ice accretion on e.g. a power line cable up to which its growth can be simulated. We utilize results of icing wind tunnel experiments and fluid dynamics simulations to explain the differences between the experiments and the theory when the collision efficiency is small. We confirm that the history term in the droplet trajectory equations becomes relevant at small collision efficiencies. Including this term, and applying the integral over the size distribution instead of using themedian volume diameter, shows that accurate modelling of icing at very small collision efficiencies is feasible. This makes it possible to estimate large rime ice loads relevant to structural design.
AB - The conventional theory of droplet collision with an object can be used only down to a collision efficiency of about 0.1. Therefore, no accurate modelling of in-cloud icing has been possible when droplets are small, wind speed is low, or the object is large. This has also put a limit on the size of an ice accretion on e.g. a power line cable up to which its growth can be simulated. We utilize results of icing wind tunnel experiments and fluid dynamics simulations to explain the differences between the experiments and the theory when the collision efficiency is small. We confirm that the history term in the droplet trajectory equations becomes relevant at small collision efficiencies. Including this term, and applying the integral over the size distribution instead of using themedian volume diameter, shows that accurate modelling of icing at very small collision efficiencies is feasible. This makes it possible to estimate large rime ice loads relevant to structural design.
KW - ice accretion
KW - rime ice
KW - collision efficiency
KW - history term
KW - droplet distribution
UR - http://www.scopus.com/inward/record.url?scp=85044470216&partnerID=8YFLogxK
U2 - 10.1016/j.coldregions.2018.03.014
DO - 10.1016/j.coldregions.2018.03.014
M3 - Article
VL - 151
SP - 133
EP - 137
JO - Cold Regions Science and Technology
JF - Cold Regions Science and Technology
SN - 0165-232X
ER -