The task of a naval architect is to ensure that, within
the limits of other design requirements, the hull form
and propulsion arrangement will be the most
efficient in the hydrodynamic sense. The ultimate
test is that the ship shall perform at the required
speed with the minimum of shaft power, and the
problem is to attain the best combination of low
resistance and high propulsive efficiency. In general
this can only be attained by a proper matching of
hull and propeller. The basic contractual obligation
laid on the shipbuilder is that the ship shall achieve
a certain speed with a specified power in good
weather on trial, and for this reason smooth-water
performance is of great importance. Model tests are
normally accepted as the superior method in
predicting the actual powering requirement for new
ship designs. They are relied upon to confirm
predictions made in the design stages. However,
methods of extrapolating the data obtained from
model test to full-scale ship play an important role in
the determination of the accuracy of the prediction.
A number of such methods are currently being used
by various towing tanks all over the world, but the
suitability of the extrapolation methods and the
correction factors on different towing tanks need to
be investigated.
OBJECTIVES The objectives of the research study are as follows: • To identify the most suitable statisticaltheoretical method for Malaysian fishing boat powering prediction; • To compare the powering prediction from extrapolation with full-scale test measurement.
METHODOLOGY Literature review is conducted from various learned sources and a 28.3 m trawler was utilized in the research. Statistical-theoretical method, model test and sea trials were performed on the vessel. Correlation analysis was conducted to determine the accuracy of the results from various methods employed. Finally the calculation for model-ship correlation was performed to determine the results of vessel resistance and powering.
CONCLUSION Statistical-theoretical method using the Holtrop and Mennen, Compton, Van Oortmerssen, Todd Series 60 and Fung methods had been utilized in the research study. Generally it was found that model tests conducted at the UTM Marine Technology Laboratory were accurate based on the ITTC standard. In this research, nevertheless it is mostly suspected that most errors occurred in the full-scale were due largely to environmental factors such as wind, wave and current at waters in the vicinity of Kuantan.
RECOMMENDATIONS For future model-ship correlation work, it is recommended that attention should be given in determining and quantifying the errors of the equipment used, especially in full-scale test. Standard procedures of full-scale tests and trials should be followed and continuous data logging/ storing system of all parameters should be used for future full scale tests. Onshore speed measurement system in conjunction with DGPS (Digital Global Positioning System) can be used to obtain more accurate measurement of vessel speed during the full-scale tests. Model Test at 1.63 m/s (11 knots) at UTM Towing Tank General Arrangement of 28.3m Trawler
REFERENCES 1.Janson and Larsson, (1996), "A Method for the Optimization of Ship Hulls from a Resistance Point of View", Proc. 21st Symp. on Naval Hydrodynamics, Trondheim, Norway. 2. Karlsen and Enerhoug, (1997), "Challenges in Trawler Design", Proc. 6th Int. Symp. on Technics and Technology in Fishing Vessels, Ancona, Italy. 3. Kristjansson, (2005), "Modelling of Powering Requirements for a Pelagic Trawler", Faculty of Engineering, Univ. of Iceland. 4. MacPherson, (1996), "Speed Prediction", Symp. on Small Craft Marine Engineering Resistance and Propulsion, Univ. of Michigan. 5.Oliveira, Fonseca and Guades Soares, (2006), "Design and Sea Performance of a Modern Purse Seiner Fishing Vessel for the Coastal Sea", Int. Journal of Small Craft Technology, RINA.
OBJECTIVES The objectives of the research study are as follows: • To identify the most suitable statisticaltheoretical method for Malaysian fishing boat powering prediction; • To compare the powering prediction from extrapolation with full-scale test measurement.
METHODOLOGY Literature review is conducted from various learned sources and a 28.3 m trawler was utilized in the research. Statistical-theoretical method, model test and sea trials were performed on the vessel. Correlation analysis was conducted to determine the accuracy of the results from various methods employed. Finally the calculation for model-ship correlation was performed to determine the results of vessel resistance and powering.
CONCLUSION Statistical-theoretical method using the Holtrop and Mennen, Compton, Van Oortmerssen, Todd Series 60 and Fung methods had been utilized in the research study. Generally it was found that model tests conducted at the UTM Marine Technology Laboratory were accurate based on the ITTC standard. In this research, nevertheless it is mostly suspected that most errors occurred in the full-scale were due largely to environmental factors such as wind, wave and current at waters in the vicinity of Kuantan.
RECOMMENDATIONS For future model-ship correlation work, it is recommended that attention should be given in determining and quantifying the errors of the equipment used, especially in full-scale test. Standard procedures of full-scale tests and trials should be followed and continuous data logging/ storing system of all parameters should be used for future full scale tests. Onshore speed measurement system in conjunction with DGPS (Digital Global Positioning System) can be used to obtain more accurate measurement of vessel speed during the full-scale tests. Model Test at 1.63 m/s (11 knots) at UTM Towing Tank General Arrangement of 28.3m Trawler
REFERENCES 1.Janson and Larsson, (1996), "A Method for the Optimization of Ship Hulls from a Resistance Point of View", Proc. 21st Symp. on Naval Hydrodynamics, Trondheim, Norway. 2. Karlsen and Enerhoug, (1997), "Challenges in Trawler Design", Proc. 6th Int. Symp. on Technics and Technology in Fishing Vessels, Ancona, Italy. 3. Kristjansson, (2005), "Modelling of Powering Requirements for a Pelagic Trawler", Faculty of Engineering, Univ. of Iceland. 4. MacPherson, (1996), "Speed Prediction", Symp. on Small Craft Marine Engineering Resistance and Propulsion, Univ. of Michigan. 5.Oliveira, Fonseca and Guades Soares, (2006), "Design and Sea Performance of a Modern Purse Seiner Fishing Vessel for the Coastal Sea", Int. Journal of Small Craft Technology, RINA.
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