In this study, added resistance was evaluated experimentally and numerically in four draft conditions: full load, ballast, and two intermediate conditions between the full load and ballast conditions. A series of towing-tank experiments for ship motion and added resistance in the four draft conditions was carried out in head sea conditions. The ship motion and added resistance were measured for the wavelength to ship length ratios of 0.4–2.0. In the numerical approach, two different seakeeping analyses were adopted: the strip method and Rankine panel method. For the strip method, analytical or empirical corrections were added in the short wave condition. The experimental and numerical results for the heave and pitch motions and the added resistance were compared for the four draft conditions. The numerical motion responses of both approaches showed good agreement with the experimental data. For the added resistance, the Rankine panel method showed reasonable results in all draft conditions. In contrast, the strip method showed poor results except in the full load condition. Based on the comparison of the experimental and numerical results, the potential application of the two numerical methods to various draft conditions was considered

This paper considers scale effects on three-dimensional (3D) sloshing flows. A series of model tests were conducted for three differently scaled tanks. The model tanks considered in this study were 1:70, 1:50, and 1:30 scaled membrane type tanks based on a 138,000 m³ liquid natural gas carrier model. The tests were carried out for harmonic sway and roll motions for three different filling depths and with various excitation frequencies. The pressure measuring points in the tanks were the same, as if they were scaled up to actual size. The main parameters investigated in this study were the pressure peak and rise time of sampled sloshing pressures. These key sloshing load parameters were systematically analysed by a statistical approach, and the results from the tests at different scales were compared.

The effect of different bow shapes on the added resistance in waves was observed through a series of model tests. To this end, three different hull forms of KRISO Very Large Crude Carrier 2 were considered: an original hull form and two modified hulls with different bow shapes, called ax-bow and leadge-bow. The model tests were conducted for a wide range of wavelengths with two wave amplitudes in a regular head-sea condition at the design speed. Each test condition was imposed at least twice in order to check the repeatability of measurement, considering the uncertainties in model test and the nonlinear nature of the added resistance. This article introduces a preliminary study on the effects of surge motion, amplitude of incident wave, and green-water allowance around bow region. This article briefly includes the uncertainty analysis of recent study regarding the performance of the original hull. Based on the results of the experimental study for three different bow shapes, the parameters which influence the added resistance and motion responses are discussed.