Incremental resistance coefficient of fast and large vessels for model ship correlation

Jaakko Pylkkänen

Research output: Contribution to journalArticleScientificpeer-review

Abstract

The purpose of this investigation is to increase the accuracy of the ITTC-57 powering performance method by splitting the incremental resistance coefficient into a sum of several terms. Analyses of published trial trip results indicate that the incremental resistance coefficient for model ship correlation of the ITTC-57 method depends also on hull form parameters. Low block coefficient ships and ships with buttock flow stern or transom stern have lower values of incremental resistance coefficient for model ship correlation than other ships of the same size and speed. On the basis of this observation a set of formulae is proposed, from which the incremental resistance coefficient of the ITTC-57 method can be calculated. The contributions to the incremental resistance coefficient due to hull roughness, ship size and speed are assumed to be conceptually similar to those used in the ITTC-78 method. The set of formulae has been applied to seventeen ships. Twelve ships have been used as the database for developing the method, and five ships as validation cases. Special scaling procedures may be needed for ships with large bow sonar domes or with other appendages of similar form. Waterjets as the propulsor and strongly cavitating conventional propellers seem to have considerable influence on the incremental resistance coefficient as derived from trial trip results.
Original languageEnglish
Pages (from-to)147-180
JournalInternational Shipbuilding Progress
Volume45
Issue number442
Publication statusPublished - 1998
MoE publication typeA1 Journal article-refereed

Fingerprint

Ship models
Ships
Sonar
Domes
Propellers
Surface roughness

Keywords

  • ships

Cite this

@article{ce753ff426ff451f9e92a739433587d0,
title = "Incremental resistance coefficient of fast and large vessels for model ship correlation",
abstract = "The purpose of this investigation is to increase the accuracy of the ITTC-57 powering performance method by splitting the incremental resistance coefficient into a sum of several terms. Analyses of published trial trip results indicate that the incremental resistance coefficient for model ship correlation of the ITTC-57 method depends also on hull form parameters. Low block coefficient ships and ships with buttock flow stern or transom stern have lower values of incremental resistance coefficient for model ship correlation than other ships of the same size and speed. On the basis of this observation a set of formulae is proposed, from which the incremental resistance coefficient of the ITTC-57 method can be calculated. The contributions to the incremental resistance coefficient due to hull roughness, ship size and speed are assumed to be conceptually similar to those used in the ITTC-78 method. The set of formulae has been applied to seventeen ships. Twelve ships have been used as the database for developing the method, and five ships as validation cases. Special scaling procedures may be needed for ships with large bow sonar domes or with other appendages of similar form. Waterjets as the propulsor and strongly cavitating conventional propellers seem to have considerable influence on the incremental resistance coefficient as derived from trial trip results.",
keywords = "ships",
author = "Jaakko Pylkk{\"a}nen",
note = "Project code: VAL03314",
year = "1998",
language = "English",
volume = "45",
pages = "147--180",
journal = "International Shipbuilding Progress",
issn = "0020-868X",
publisher = "IOS Press",
number = "442",

}

Incremental resistance coefficient of fast and large vessels for model ship correlation. / Pylkkänen, Jaakko.

In: International Shipbuilding Progress, Vol. 45, No. 442, 1998, p. 147-180.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Incremental resistance coefficient of fast and large vessels for model ship correlation

AU - Pylkkänen, Jaakko

N1 - Project code: VAL03314

PY - 1998

Y1 - 1998

N2 - The purpose of this investigation is to increase the accuracy of the ITTC-57 powering performance method by splitting the incremental resistance coefficient into a sum of several terms. Analyses of published trial trip results indicate that the incremental resistance coefficient for model ship correlation of the ITTC-57 method depends also on hull form parameters. Low block coefficient ships and ships with buttock flow stern or transom stern have lower values of incremental resistance coefficient for model ship correlation than other ships of the same size and speed. On the basis of this observation a set of formulae is proposed, from which the incremental resistance coefficient of the ITTC-57 method can be calculated. The contributions to the incremental resistance coefficient due to hull roughness, ship size and speed are assumed to be conceptually similar to those used in the ITTC-78 method. The set of formulae has been applied to seventeen ships. Twelve ships have been used as the database for developing the method, and five ships as validation cases. Special scaling procedures may be needed for ships with large bow sonar domes or with other appendages of similar form. Waterjets as the propulsor and strongly cavitating conventional propellers seem to have considerable influence on the incremental resistance coefficient as derived from trial trip results.

AB - The purpose of this investigation is to increase the accuracy of the ITTC-57 powering performance method by splitting the incremental resistance coefficient into a sum of several terms. Analyses of published trial trip results indicate that the incremental resistance coefficient for model ship correlation of the ITTC-57 method depends also on hull form parameters. Low block coefficient ships and ships with buttock flow stern or transom stern have lower values of incremental resistance coefficient for model ship correlation than other ships of the same size and speed. On the basis of this observation a set of formulae is proposed, from which the incremental resistance coefficient of the ITTC-57 method can be calculated. The contributions to the incremental resistance coefficient due to hull roughness, ship size and speed are assumed to be conceptually similar to those used in the ITTC-78 method. The set of formulae has been applied to seventeen ships. Twelve ships have been used as the database for developing the method, and five ships as validation cases. Special scaling procedures may be needed for ships with large bow sonar domes or with other appendages of similar form. Waterjets as the propulsor and strongly cavitating conventional propellers seem to have considerable influence on the incremental resistance coefficient as derived from trial trip results.

KW - ships

M3 - Article

VL - 45

SP - 147

EP - 180

JO - International Shipbuilding Progress

JF - International Shipbuilding Progress

SN - 0020-868X

IS - 442

ER -