• Journal of the Society of Naval Architects of Korea
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• v.51 no.5
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• pp.429-434
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• 2014

The main objective of the present study is to elucidate a correlation between ship resistances from computational fluid dynamics (CFD) and brake horse powers (BHP) from towing tank in container carriers. The tests were conducted for a range of combinations of trim conditions and speeds. To achieve this goal, 295 cases of numerical simulation have been performed using Star-CCM+ which had been statistically verified to predict ship resistances (Lee & Lee, 2014). Based on the normal distribution of resistance errors in all cases of the 4 container carriers, the confidence interval of numerical error was estimated as [-2.33%,+2.42%] with 95% confidence. The correlation coefficients between the ship resistances of CFD and the brake horse powers of the experiments were higher than 0.93. As a result, the numerical calculation of ship resistances is able to be utilized in order to provide a quick guidance in selection of the optimum loading condition.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.173-178
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• 2004

The estimation of springing responses for recent ships are carried out and application to a ship design are described. To this aim, springing effects on hull girder were re-evaluated including non-linear wave excitations and torsional vibrations of the hull. The Timoshenko beam model was used to calculate stress distribution on the hull girder by the superposition method. The strip method was employed to calculate the hydrodynamic forces and moments on the hull. In order to remove the irregular frequencies, we adopted 'rigid lid' on the hull free surface level and added asymptotic interpolation along the high frequency range. Several applications to the existing ships were carried out. They are Bishop and Price's container ship, S-175 container ship, large container, VLCC and ore carrier. One of them is compared with ship measurement result while another with that of model test. Comparison between analytical solution and numerical one for homogeneous beam type artificial ship shows good agreement. It is found that most springing energy came from high frequency waves for the ships having low natural frequency and North Atlantic route etc. Therefore, the high frequency tail of the wave spectrum should be increased by $\omega^{-3}\;instead\;of\;\omega^{-4}\;or\;\omega^{-5}$ for springing calculation.

• Bulletin of the Society of Naval Architects of Korea
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• v.27 no.3
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• pp.1-10
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• 1990

This paper represents the hull form development of a high speed container ship based on the thin ship theory, Hess & Smith method, the reference ship data and model test results. The high efficiency propeller designed by the lifting surface theory shows good performance in the cavitation and the pressure fluctuation force. Also, the optimum design technique based on the finite element method was adopted for the hull structure design and the hull vibration analysis. Finally, the performance of a newly developed container ship has been compared with the sea trial results and the excellent performance in speed, vibration, etc. was confirmed.

• Journal of the Korean Society for Marine Environment & Energy
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• v.6 no.3
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• pp.16-25
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• 2003

In this paper, the reduction of green house effect gas CO₂ emission and NOx gas emission by using the RORO ship coastal transport of import-export container cargo was investigated. At first, the domestic CO₂ gas emission and the transportation of import-export container cargo were Investigated. Next, the characteristic of a RORO ship and CO₂ emission standard and NOx emission standard were investigated. And also, the reduction of CO₂ emission and NOx emission by the shift of coastal transport from land transport for the transportation of import-export container cargo between Kyongin area and Pusan Port were calculated. Finally, the change of CO2 and NOx gas emission due to the change of the share of coastal transportation and the load efficiency of RORO ship are investigated. The research results show that the shift of RORO ship coastal transport from land transport was very effective to reduce the CO₂ emission but it was no good to reduce the NOx emission.

• Journal of Fisheries and Marine Sciences Education
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• v.10 no.1
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• pp.1-14
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• 1998

Transportation provides an infrastructure vital to economic growth, and it is also an integral part of production. As a port is regarded as the interface between the maritime transport and domestic transport sectors, it certainly play a key role in any economic development. Ship's delay caused by port congestion has recently has recently attracted attended with the analysis of overall operation in port. In order to analyse complicated port operation which contains large number of variable factors, queueing theory is needed to be adopted, which is applicable to a large scale transportation system in chiding ship's delay in Inchon port in relation to ship's delay problem. The overall findings are as follows ; 1. The stucture of queueing model in this port can be represented as a complex of multi-channel single-phase 2. Ship's arrival and service pattern were Poisson Input Erlangian Service. 3. The suitable formula to calculate the mean delay in this port, namely, $W_q={\frac{{\rho}}{{\lambda}(1-{\rho})}}{\frac{e{\small{N}}({\rho}{\cdot}N)}{D_{N-1}({\rho}{\cdot}N)}}$ Where, ${\lambda}$ : mean arrival rate ${\mu}$ : mean servicing rate N : number of servicing channel ${\rho}$ : utilization rate (l/Nm) $e{\small{N}}$ : the Poisson function $D_{(n-1)}$ : a function of the cumulative Poisson function 4. The utility rate is 95.0 percents in general piers, 75.39 percents in container piers, and watiting time 28.43 hours in general piers, 13.67 hours in container piers, and the length of queue is 6.17 ships in general piers, 0.93 ships in container piers, and the ship turnaround time is 107.03 hours in general piers, 51.93 hours in container piers.

• Special Issue of the Society of Naval Architects of Korea
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• 2011.09a
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• pp.95-100
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• 2011

In general, thickness of bottom floor in fore/aft cargo hold region for container ship has been determined based on FEM analysis result of mid cargo hold region. But this approach has room for improvement because section shape and frame spacing in fore/aft cargo hold of container ship are quietly different from those of mid cargo hold. From this study, correlation between FEM result and grillage analysis result has been investigated and simple method for thickness determination of bottom floor in fore/aft cargo hold using newly improved grillage analysis is proposed.

• Industrial Engineering and Management Systems
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• v.9 no.1
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• pp.28-40
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• 2010

One of the most important objectives of the schedules in a container terminal is to minimize the ship operation time, which consists of discharging and loading operation times. Recently, dual cycling techniques have been used for improving terminal operations, especially for reducing the total empty trips of handling equipment. The main focus of this study is to reduce the empty trip times of yard trucks with minimum delays for ship operations. A heuristic algorithm, modified from a previous algorithm, is proposed to solve this problem. A simulation study is conducted to evaluate the effect of different types of discharging and loading schedules and different locating methods for discharging containers in terms of the performance of the system, including the percentage of the dual cycle operations of yard trucks.

• Bulletin of the Society of Naval Architects of Korea
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• v.25 no.1
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• pp.3-10
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• 1988

This paper presents some experimental investigations on the effectiveness of the Stern-End-Bulb(SEB) and the design procedure of the optimum one. Experimental method was discussed to search the optimum SEB and the resistance reduction rate was investigated from the resistance test results of the SEB series for a passenger boat and a container ship. The contribution of SEB on the propulsive coefficients was discussed from the self-propulsion test results for a container ship. It would be expected that the power saving rate is about 5.8 percents for a passenger boat and 3.6 percents for a container ship by optimum SEB, respectively.

• Journal of Ship and Ocean Technology
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• v.5 no.4
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• pp.44-50
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• 2001

Large container carriers are suffering from lack of knowledge on reliable correlation allowances between model tests and full-scale trials, especially at fully loaded condition, Careful full-scale sea trial with a full loading of containers both in holds and on decks was carried out to clarify it. Model test results were analyzed by different methods but with the same measuring data to figure out appropriated correlations factors for each analysis methods, Even if it is no doubt that model test technique is one of the most reliable tool to predict full scale powering performance, its assumptions and simplifications which have been applied on the course of data manipulation and analysis need a feedback from sea trial data for a fine tuning, so called correlation factor. It can be stated that the best correlation allowances at fully loaded condition for both 2-dimensional and 3-dimensional analysis methods are fecund through the careful sea trial results and relevant study on the large size container carriers.

• Bulletin of the Society of Naval Architects of Korea
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• v.20 no.4
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• pp.25-32
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• 1983

A series of model testes on a container ship in regular were executed. This paper presents the results of resistance, self-propulsion, and ship motion tests. The experimental results of ship motion measured on a towed model and a self-propelled model were compared with those of Japanese's model test showing fairly good agreements. The results of added resistance tests were compared with those of Japanese' model test and also compared with the calculation results by Gerritsma's method showing somewhat large discrepancies at higher speeds. Also the results of added resistance tests measured on a fixed model were compared with the calculation results by Gerritsma's method. Finally the results of self-propulsion tests were presented.