The sloshing response is crucial to the design and operation of aquaculture vessels and affects the safety of the culture equipment and the efficiency of the culture operation. A 1/50 scaled model was utilized to investigate the coupled sloshing response characteristics of a novel aquaculture vessel in a wave basin. Two wave directions (beam and head wave) and two filling levels (81.5% and 47.4%) are taken into account. The time-domain and frequency-domain characteristics of the sloshing response under the linear regular wave and extreme operational sea state were investigated using regular wave tests and irregular wave tests, respectively. The sloshing mechanism in the aquaculture tanks is complicated, due to the coupling effect between external waves, ship motion, and internal sloshing. In linear regular waves, the wave frequency mode dominates the sloshing response, which is larger under beam wave conditions than under head wave conditions and larger under half load conditions than full load conditions. The irregular wave test results confirmed the regular wave test conclusions, but the sloshing response has stronger nonlinearity, higher natural modes appeared, and the amplitude of the higher natural modes is also relatively larger.

Moonpools on drilling vessels are structures located at the mid-ship position to facilitate drilling and other marine operations. The existence of the moonpools is prone to bothersome intense resonant fluid behaviors even other unexpected violent non-linear phenomena under external excitations, especially for those types with one or more recesses. The presented study focuses on the

Calm water resistance of ship is an important index of ship design and performance evaluation, which has an extremely important impact on ship operation capacity, fuel consumption, speed and navigation stability. In order to accurately predict the calm water resistance of the hull, this research investigates the detailed analysis process of hull resistance in calm water using the commercial computational fluid dynamics software STAR-CCM+. The extremely large oil tanker KVLCC2, the container ship KCS, and the navy destroyer DTMB5415's resistance values at various speeds are computed, accordingly, by the use of a sensible meshing approach. In this study, the model test results and the numerical resistance prediction findings based on the grid division are compared. The maximum difference between the results of the numerical simulation and the results of the model test is kept to a maximum of 5%, and the average error is kept to a minimum of 2%. The agreement between the resistance predictions from the numerical simulation and the model test demonstrates the accuracy and dependability of the meshing procedure used in this study and serves as a guide for calculating resistance for the majority of ships operating in calm water.

The hydrodynamic response of closed and semi-closed (open-bottom) rigid cylindrical aquaculture platforms was examined through combined model tests and numerical simulations. Free decay tests in calm water quantified natural periods and damping ratios for heave and pitch motions. Subsequent regular wave testing characterized response amplitude operators (RAOs) and wave elevations at interior and exterior wave gauges. Finally, the motion and wave elevation characteristics of the two types of aquaculture platforms under irregular waves were analyzed under extreme sea conditions. Results demonstrated that bottom openings significantly altered hydrodynamic responses of aquaculture platforms, with a 59% enhancement in heave damping ratio and a 47% reduction in heave natural period. Semi-closed cages exhibited asymmetric internal sloshing profiles along the mid-transverse axis, with lateral sloshing amplitudes increasing by 200–300% at lateral wave gauges. Under irregular wave conditions, compared to closed aquaculture platform, semi-closed aquaculture platform increased the heave, pitch motion, and internal sloshing response but reduced run-up on the outer wave-facing side.