Ice induced resistance of ship hulls: A comparison of resistance estimated from measurements and analytical formulations
Due to global warming and hydrocarbon exploration in the Arctic areas, there is an increasing maritime activity in ice infested waters. Today one can with good accuracy predict if a vessel will be able to survive an encounter with ice of a given thickness, but the knowledge is not good enough to pre...
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Norges teknisk-naturvitenskapelige universitet, Fakultet for ingeniørvitenskap og teknologi, Institutt for marin teknikk
2011
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Online Access: | http://hdl.handle.net/11250/237952 |
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ftntnutrondheimi:oai:ntnuopen.ntnu.no:11250/237952 2023-05-15T14:51:06+02:00 Ice induced resistance of ship hulls: A comparison of resistance estimated from measurements and analytical formulations Skår, Torstein Norges teknisk-naturvitenskapelige universitet, Fakultet for ingeniørvitenskap og teknologi, Institutt for marin teknikk 2011 http://hdl.handle.net/11250/237952 eng eng Norges teknisk-naturvitenskapelige universitet, Fakultet for ingeniørvitenskap og teknologi, Institutt for marin teknikk 492151 http://hdl.handle.net/11250/237952 Master thesis 2011 ftntnutrondheimi 2019-09-17T06:48:48Z Due to global warming and hydrocarbon exploration in the Arctic areas, there is an increasing maritime activity in ice infested waters. Today one can with good accuracy predict if a vessel will be able to survive an encounter with ice of a given thickness, but the knowledge is not good enough to predict the increased fuel cost for ice navigation. This thesis has investigated the validity of two analytical formulations for ice resistance in Arctic areas. The formulations are based on full-scale ice trials in the Finnish-Swedish waters, which have lower salinity and warmer climate than the Arctic areas. This is done by comparing the resistance estimated from onboard measurements of vessel speed, ice thickness and engine power with the estimates from the analytical formulations. The ratio between the two is investigated using statistical tools. While most of the data have too much variation for any conclusions to be made, some time sequences without large variation in the resistance has been identified. Analysis from these sequences indicate that the formulation presented by Riska et al. (1997) appears to be able to describe the speed dependency of ice resistance in the Arctic, but is inaccurate when describing the ice thickness dependence. The formulation presented by Lindqvist (1989) is found to be inaccurate when describing both ice thickness and speed dependency. It is unclear whether the source of inaccuracy comes from incorrect ice property values or if the formulations have been used outside their area of application (both are based on ice trials in the Baltic Sea). Master Thesis Arctic Global warming NTNU Open Archive (Norwegian University of Science and Technology) Arctic |
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Open Polar |
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NTNU Open Archive (Norwegian University of Science and Technology) |
op_collection_id |
ftntnutrondheimi |
language |
English |
description |
Due to global warming and hydrocarbon exploration in the Arctic areas, there is an increasing maritime activity in ice infested waters. Today one can with good accuracy predict if a vessel will be able to survive an encounter with ice of a given thickness, but the knowledge is not good enough to predict the increased fuel cost for ice navigation. This thesis has investigated the validity of two analytical formulations for ice resistance in Arctic areas. The formulations are based on full-scale ice trials in the Finnish-Swedish waters, which have lower salinity and warmer climate than the Arctic areas. This is done by comparing the resistance estimated from onboard measurements of vessel speed, ice thickness and engine power with the estimates from the analytical formulations. The ratio between the two is investigated using statistical tools. While most of the data have too much variation for any conclusions to be made, some time sequences without large variation in the resistance has been identified. Analysis from these sequences indicate that the formulation presented by Riska et al. (1997) appears to be able to describe the speed dependency of ice resistance in the Arctic, but is inaccurate when describing the ice thickness dependence. The formulation presented by Lindqvist (1989) is found to be inaccurate when describing both ice thickness and speed dependency. It is unclear whether the source of inaccuracy comes from incorrect ice property values or if the formulations have been used outside their area of application (both are based on ice trials in the Baltic Sea). |
author2 |
Norges teknisk-naturvitenskapelige universitet, Fakultet for ingeniørvitenskap og teknologi, Institutt for marin teknikk |
format |
Master Thesis |
author |
Skår, Torstein |
spellingShingle |
Skår, Torstein Ice induced resistance of ship hulls: A comparison of resistance estimated from measurements and analytical formulations |
author_facet |
Skår, Torstein |
author_sort |
Skår, Torstein |
title |
Ice induced resistance of ship hulls: A comparison of resistance estimated from measurements and analytical formulations |
title_short |
Ice induced resistance of ship hulls: A comparison of resistance estimated from measurements and analytical formulations |
title_full |
Ice induced resistance of ship hulls: A comparison of resistance estimated from measurements and analytical formulations |
title_fullStr |
Ice induced resistance of ship hulls: A comparison of resistance estimated from measurements and analytical formulations |
title_full_unstemmed |
Ice induced resistance of ship hulls: A comparison of resistance estimated from measurements and analytical formulations |
title_sort |
ice induced resistance of ship hulls: a comparison of resistance estimated from measurements and analytical formulations |
publisher |
Norges teknisk-naturvitenskapelige universitet, Fakultet for ingeniørvitenskap og teknologi, Institutt for marin teknikk |
publishDate |
2011 |
url |
http://hdl.handle.net/11250/237952 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Global warming |
genre_facet |
Arctic Global warming |
op_relation |
492151 http://hdl.handle.net/11250/237952 |
_version_ |
1766322160951885824 |