Open Access Repository

Slam loads and kinematics of wave-piercing catamarans during bow entry events in head seas

Downloads

Downloads per month over past year

Shabani, B, Lavroff, J ORCID: 0000-0001-5262-8666, Davis, MR, Holloway, DS ORCID: 0000-0001-9537-2744 and Thomas, GA 2018 , 'Slam loads and kinematics of wave-piercing catamarans during bow entry events in head seas' , Journal of Ship Research, vol. 62, no. 3 , pp. 134-155 , doi: 10.5957/JOSR.180001.

[img] PDF
129018 - Slam l...pdf | Request a copy
Full text restricted

Abstract

Centre bow (CB) design for wave-piercing catamarans (WPCs) is a critical compromise between minimization of slamming and protection against deck diving. To inform the design process, this article investigates the slam loads and kinematics during bow entry events in regular head seas for a 112-mWPC with systematic variations to its CB and wet-deck geometry. Model tests using a 2.5-m hydroelastic segmented catamaran considered five different CB configurations, designated as the parent, high, low, long, and short CB. The results indicated that changes in the CB length had little effect on the general kinematic trends obtained for the pitch, heave, and bow vertical displacement at the instant of slamming, but increasing the wet-deck height resulted in an increase in heave (but not pitch) at slamming. Two new design ratios are proposed. The CB immersion depth to arch height ratio showed slamming occurring in the range of 0.3-0.6 depending on the wave encounter frequency and the CB configuration. The CB buoyancy in the encountered waves was estimated by considering both immersion depth and area along the CB in waves through relative motion analyses. It was found that the buoyancy to slam force ratio increased with increasing wet-deck height but not with increasing CB length. This suggests that an optimal CB configuration could be achieved by first modifying the arched cross-structure to reduce the arch filling effect on slamming severity and then maximizing the CB buoyancy to slam force ratio by increasing either the wet-deck height or the CB length.

Item Type: Article
Authors/Creators:Shabani, B and Lavroff, J and Davis, MR and Holloway, DS and Thomas, GA
Keywords: wave-piercing catamaran, hydroelastic segmented model, ship kinematics, relative motion, CB design, wet-deck slamming
Journal or Publication Title: Journal of Ship Research
Publisher: Soc Naval Arch Marine Eng
ISSN: 0022-4502
DOI / ID Number: 10.5957/JOSR.180001
Copyright Information:

© 2018. Article copyright remains with the publisher, society or author(s) as specified within the article.

Related URLs:
Item Statistics: View statistics for this item

Actions (login required)

Item Control Page Item Control Page
TOP