Trans RINA, Vol 152, Part A4, Intl J Maritime Eng, Oct-Dec 2010
speed Green function, with a forward speed correction in the frequency domain, with the experimental results:
• The theory under predicts the roll motion of the frigate whilst the theoretical heave and pitch RAOs for the frigate correlate relatively well with their respective experimental results.
• The correlation for the supply vessel heave and pitch motions is excellent.
frequencies line up well with very little deviation between the theoretical and experimental
The peak magnitudes and results
across the frequency range examined. However the roll motions of supply vessel are not well predicted.
• When the motions of the vessels in irregular seas were examined in terms of the extreme value with 1 percent exceedence probability in 3 hours; the theory under-predicted both the extreme roll motion of the frigate and the relative motion between the RAS points.
This work shows that to determine the optimal RAS operational scenario, including vessel separation, it is vital that the motions of the individual vessels are not considered in isolation, rather all motions need to be considered for both vessels simultaneously.
7. ACKNOWLEDGEMENTS
The authors would like to acknowledge the work of James Caspar in the conduct of the experiments.
towing tank Dr Stuart Cannon, Defence Science and
Technology Organisation, is also acknowledged for his support of this project.
8. 1.
REFERENCES
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9. Further
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©2010: The Royal Institution of Naval Architects
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