• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.5
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• pp.583-590
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• 2018

The objective of this study is to present a resistance performance map developed using the dimension parameters of a bilge keel appendage attached to a fishing vessel using CFD. The dimension parameters consist of three length and breadth measures of a bilge keel appendage from nine selected cases. The size of a bilge keel attached to an existing ship should be 90 % of the ship length and 5 % of the ship breadth. In this study, bilge keels with a length of 63 %, 77 % and 90 % and a breadth of 5 %, 7 % and 9 % were considered based on ship length and breadth. The effective power in each of the nine cases was predicted using CFD. Based on results from an existing ship, effective power in the case with the shortest length and longest breath was reduced by 0.3 %. The case with the longest length and breadth showed an increase in effective power of 1.7 %. The case with the shortest length and breadth showed a decrease in effective power of 2.3 %. The proposed map can be utilized to select dimensions according to the sailing and work patterns of fishing vessels from the perspective of resistance performance.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.6
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• pp.688-696
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• 2023

In the present study, free roll decay and resistance performances of fishing vessels were evaluated with the combinations and variations of in the parameters of appendages which are attached to improve motion performance of fishing vessels. Computational Ffluid Ddynamics was used to perform free roll decay and resistance analysis. The roll period and decay coefficient were derived by the variations in the combination and dimensions of the primary appendages of the bilge keel and the under keel. It was observed thatThe variations of in the length of the under keel did not significantly impact to the roll damping coefficient. Conversely, for the bilge keel, an increase in the length and angle resulted in an increase in the roll damping coefficient. Comparison of resistance performance was additionally assessed among the selected hulls with the appendages and bare hull. The resistance of the hull with the appendages was higher than that of the bare hull due owing to the changes of in the pressure on the surface of the hull and trim angle. Throughout the present study, the impact of appendage parameter and arrangement on the free roll decay and resistance performance of fishing vessels were was assessed,. which This will be beneficial for the application of appendages to fishing vessels.

• Journal of the Society of Naval Architects of Korea
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• v.37 no.2
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• pp.30-37
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• 2000

The roll damping characteristics of the three models of a 3ton class fishing vessel, that is the bare hull, hull with bilge keels, and hull with bilge keels and a central wing are investigated by the free roll tests in head waves in a towing tank with the variations of the forward speed, initial angle and OG. The wave length variations are also included. The experimental results are compared with the numerical results of mathematical modellings by the energy method for these three models and the energy dissipation patterns are also compared. The roll damping speed increases, the effect of the waves on the roll damping of the models with the additional devices is negligible due to the much increased damping caused by the lift increase.

• Journal of Navigation and Port Research
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• v.40 no.6
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• pp.361-368
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• 2016

A ship's rolling motion can make crew and passengers sick and/or apply forces to the structure that cause damage.. Therefore bilge keels are equipped in most ships for anti-rolling. In special cases, anti-rolling tanks (ARTs), fin stabilizers, or gyroscopes can be installed. However, ARTs require a large area to install, and fin stabilizers and gyroscopes are costly to install and expensive to operate. This paper suggests a Anti-rolling pendulum (ARP) to reduce roll motion. ARPs acts like ARTs. However, the ARP has a circular shaped guidance arc instead of the string or wire of a simple pendulum. The device suggested has about 1/ 8 the weight and 1/ 6 the volume of a ART and is more effective. This study derives the nonlinear and linear differential equations of system motion.