Atmospheric icing: Difference between revisions
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Not all water freezes at {{convert|0|°C|°F|disp=or}}. Liquid water below this temperature is called [[supercooling|supercooled]], and such supercooled droplets cause the icing problems on aircraft. Below {{convert|−20|°C}}, icing is rare because clouds at these temperatures usually consist of ice particles rather than supercooled water droplets. Below {{convert|−48|°C|1}}, supercooled water cannot exist, therefore icing is impossible.<ref>{{cite journal|last=Moore|first=Emily|author2=Valeria Molinero |title=structural transformation in supercooled water controls the crystallization rate of ice|journal=Nature|date=24 November 2011|volume=479|pages=506–508|doi=10.1038/nature10586|url=http://arxiv.org/abs/1107.1622|accessdate=24 November 2011|arxiv = 1107.1622 |bibcode = 2011Natur.479..506M }}</ref> |
Not all water freezes at {{convert|0|°C|°F|disp=or}}. Liquid water below this temperature is called [[supercooling|supercooled]], and such supercooled droplets cause the icing problems on aircraft. Below {{convert|−20|°C}}, icing is rare because clouds at these temperatures usually consist of ice particles rather than supercooled water droplets. Below {{convert|−48|°C|1}}, supercooled water cannot exist, therefore icing is impossible.<ref>{{cite journal|last=Moore|first=Emily|author2=Valeria Molinero |title=structural transformation in supercooled water controls the crystallization rate of ice|journal=Nature|date=24 November 2011|volume=479|pages=506–508|doi=10.1038/nature10586|url=http://arxiv.org/abs/1107.1622|accessdate=24 November 2011|arxiv = 1107.1622 |bibcode = 2011Natur.479..506M }}</ref> |
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Icing also occurs on [[tower]]s, [[wind turbine]]s, [[boat]]s, [[Drilling rig|oil rigs]], trees and other objects exposed to low temperatures and water droplets. Ice loads are a major cause of catastrophic failures of overhead electric power lines. Their estimation is, therefore, crucial in the structural design of power line systems.<ref>Farzaneh, M. (2008) Atmospheric Icing of Power Networks. Springer Science & Business Media, 2008, 381 p. ISBN |
Icing also occurs on [[tower]]s, [[wind turbine]]s, [[boat]]s, [[Drilling rig|oil rigs]], trees and other objects exposed to low temperatures and water droplets. Ice loads are a major cause of catastrophic failures of overhead electric power lines. Their estimation is, therefore, crucial in the structural design of power line systems.<ref>Farzaneh, M. (2008) Atmospheric Icing of Power Networks. Springer Science & Business Media, 2008, 381 p. ISBN 978-1-4070-8530-7</ref> and can be done by numerical icing models that utilize meteorological data.<ref>Makkonen, L. (2000) Models for the growth of rime, glaze, icicles and wet snow deposits on structures. Philosophical Transactions of the Royal Society, London A, 358 (1776): 2913-2939.</ref> |
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==Aircraft incidents== |
==Aircraft incidents== |
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Revision as of 07:20, 2 August 2015
 | It has been suggested that this article be merged with Icing conditions. (Discuss) Proposed since August 2012. |
Atmospheric icing occurs when water droplets in the atmosphere freeze on objects they contact. This can be extremely dangerous to aircraft, as the built-up ice changes the aerodynamics of the flight surfaces, which can increase the risk of a subsequent stalling of the airfoil. For this reason, ice protection systems are often considered critical components of flight, and aircraft are often deiced prior to take-off in icy environments.
Not all water freezes at 0 °C or 32 °F. Liquid water below this temperature is called supercooled, and such supercooled droplets cause the icing problems on aircraft. Below −20 °C (−4 °F), icing is rare because clouds at these temperatures usually consist of ice particles rather than supercooled water droplets. Below −48 °C (−54.4 °F), supercooled water cannot exist, therefore icing is impossible.[1]
Icing also occurs on towers, wind turbines, boats, oil rigs, trees and other objects exposed to low temperatures and water droplets. Ice loads are a major cause of catastrophic failures of overhead electric power lines. Their estimation is, therefore, crucial in the structural design of power line systems.[2] and can be done by numerical icing models that utilize meteorological data.[3]
Aircraft incidents
A number of aircraft crashes have been caused by ice. In other incidents icing was a contributory factor.
References
- ^ Moore, Emily; Valeria Molinero (24 November 2011). "structural transformation in supercooled water controls the crystallization rate of ice". Nature. 479: 506–508. arXiv:1107.1622. Bibcode:2011Natur.479..506M. doi:10.1038/nature10586. Retrieved 24 November 2011.
- ^ Farzaneh, M. (2008) Atmospheric Icing of Power Networks. Springer Science & Business Media, 2008, 381 p. ISBN 978-1-4070-8530-7
- ^ Makkonen, L. (2000) Models for the growth of rime, glaze, icicles and wet snow deposits on structures. Philosophical Transactions of the Royal Society, London A, 358 (1776): 2913-2939.
See also
References
- FAA (U.S.) Advisory Circular 20-113: Pilot Precautions and Procedures to be taken in Preventing Aircraft Reciprocating Engine Induction System and Fuel System Icing Problems
- FAA (U.S.) Advisory Circular 20-117: Hazards Following Ground Deicing and Ground Operations in Conditions Conducive to Aircraft Icing
- FAA (U.S.) Advisory Circular 20-147: Turbojet, Turboprop, and Turbofan Engine Induction System Icing and Ice Ingestion
- Wind Energy in Cold Climates: Icing on wind turbines