LNG propulsion ships are actively being built as an eco-friendly fuel for ships, and ships with C-type LNG tanks are being widely built. In order to analyze the risk of LNG venting from operating ships and test-run ships, the flow characteristics according to operating conditions were reviewed using ANSYS FLUENT, a computational fluid dynamics (CFD) software. As a result of the study, it was confirmed that the distribution area exceeding the lower explosion limit of natural gas and the area where the natural gas temperature rose to 17 ° C had similarities. In addition, it was confirmed that the change in the horizontal direction was greater than the change in the vertical direction when the natural gas distribution range was changed. Since the valve opening has a greater effect than the tank pressure, if natural gas must be vented to the atmosphere inevitably, the risk can be reduced by operating the valve opening at 50% or less.

In this study, in order to observe the effect of guide bar installation conditions on the ship’s anchor containment by varying the guide bar installation conditions were comprehensively observed. The proper installation of the guide bar, it is possible to improve the hammering phenomenon that occurs when the anchor chain falls vertically. It was confirmed that the anchor storage condition could be improved not only by the guide bar, but also by adding a welding bead at an appropriate location. The capacity of the power source has a significant effect on the anchor pendulum motion.