Crest of the Royal National Institution of Naval Architects - Click to return to the homepage

The Royal Institute of Naval Architects

Jotun 09/11/2016

Bentley Systems 10/11/16

IJME 305

Paper title:  Superior Seaworthiness of a Resonance-Free Fast Oceangoing SWATH

 

Authors

M Yoshida, Kyushu University, Japan
H Kihara, National Defense Academy of Japan, Japan
H Iwashita, Hiroshima University, Japan, M Kanda, Akishima Laboratories (Mitsui Zosen) Inc., Japan
T Kinoshita,The University of Tokyo, Japan

Summary 

The speed reduction, additional resistance or slamming caused by the large amplitude ship motions, should be completely restricted for a large fast oceangoing ship because of the strict time-punctuality and the high value of the cargo. A “Resonance-Free SWATH (RFS)”, which has negative restoring moments due to the extremely small water plane area, is introduced to minimize the motion responses. A motion control system using small fins is necessary for the RFS, which has no stability during high speed cruising. Theoretical estimations and experiments to search for the optimum values of PD control gains have been performed. Unsteady characteristics of fin-generated lift such as the time lag and the interaction among the fins and lower hulls have been measured and they are taken into account in the motion equations. Then, experiments using the RFS model with controlling fins have been carried out to validate the theoretical estimation for the motion responses of the RFS in waves. The theoretical and experimental results agree well with each other. The motion responses of the RFS in regular and irregular head waves are compared with those of other hull forms, such as a mono-hull, an ordinary SWATH and a trimaran. The clear advantage of the RFS regarding the seaworthiness has been found. In summary, the heave motion response of the RFS is reduced to 1/60 and the pitch motion becomes1/8, compared with those of the existing mono-hull ship.

Reference

Transactions RINA, Vol 156, Part A4, International Journal Maritime Engineering, Oct-Dec 2014 

DOI Number

DOI No: 10.3940/rina.ijme.2014.a4.305

Search and Order IJME papers

All International Journal of Maritime Engineering (IJME) papers are listed in the RINA Publications Database. You can search the database by author name and paper title. Publications may be ordered and paid for online. Other publications are also listed, some of which may be downloaded free of charge. Follow the link to Search Publications & Order.

Alfa Laval 260x120

Stone Marine 260x120

Rolls Royce Marine 2016

JETS VAC July 2015

KnudNoSMM2

Drew Safety