A light-weight cantilever type towing carriage was devised and installed in the towing tank at Seoul National University. Wireless measurement devices were also provided for appropriate data acquisition during high-speed towing tests. With the new carriage system, a series of model tests were performed to investigate the hydrodynamic characteristics of the racing boat in the towing tank and the resistance test results had sufficient accuracy so that they could be used in the development of a high speed planning hull.

A mixed-flow pump is largely applied for waterjet propulsion in high-speed vessels because of excellent cavitation performance. For the present study, we analyze the performance of mixed-flow pump, which is composed of impeller and stator. The test device for a mixed-flow pump was installed in the test section in the KRISO cavitation tunnel. The performance tests of two mixed-flow pumps were carried out with the test device at various flow rates using various nozzles. The test results agree fairly well with the predicted results by commercial CFD code. The test device is available for verification of impeller performance together with CFD analysis

Recently moored offshore vessels like as FPSO(Floating Production Storage Offloading) are frequently deployed in seas for a long time. For successful operation, the motion behavior of such a vessel in waves must be clarified in advance either theoretically or experimentally. It is of particular interest to examine the behavior, when swells are superposed to seas with different incident angle. Such a situation is actually reported in some offshore oilfield. In this paper, the motion of a FPSO in irregular waves including swells is studied in time domain. Hydrodynamic coefficients and wave forces are calculated in frequency domain using three-dimensional singularity distribution method. Time memory function and added mass at infinite frequency are derived by Fourier transform utilizing hydrodynamic damping coefficients. In the process, the numerical accuracy of added mass at infinite frequency is carefully examined in association with free decay simulations. It is found from numerical simulations that swells significantly affect the vertical motion of FPSO mainly because of their longer period compared to the ordinary sea waves. In particular, the roll motion is largely amplified because the dominant period of swell is closer to the roll natural period than that of seas.

A hull form of Baltic ice class IA Aframax tanker has been developed taking into consideration of powering performance in brash ice channels based on IA class rules. Speed performance of the ship hull form in normal seagoing has been validated through model tests in a towing tank. The hull form design developed in this work has demonstrated good speed performance in normal seagoing although the ship design is entitled to ice class IA.