Cavitation is a process of liquid evaporation, bubble or vapor sheet formation, and further collapse structures, which plays destructive role in many industrial applications. In marine transport hydraulic machinery, cavitation usually occurs nearby the surface ship propeller rudder, impeller blades pump, distributor vanes runner hydroturbine causes various undesirable effects such as vibrations frameworks and/or moving parts, material erosion, noise enhancement. Based on an extensive...

This paper presents systematic comparisons of experiments against fluid structure interaction (FSI) simulations for flat water plate entry. Special focus is attributed on hydroelasticity and air trapping effects, quantification the experimental numerical uncertainties validity modelling assumptions prediction bottom slamming induced loads. Consequently, American society Mechanical Engineers standard Verification Validation used to estimate errors. Numerical results agree favourably. It shown...

We experimentally investigated a passive cavitation control approach to partial and cloud on National Advisory Committee for Aeronautics 0015 hydrofoil. For this approach, we implemented two different kinds of mesoscale bio-inspired riblets, known as scalloped riblets sawtooth the suction side hydrofoil near its leading edge. studied dynamics with without using high-speed camera. In addition, performed hydro-acoustic measurements analyze effects induced noise in wake hydrofoils. considered...

A new Rankine panel method and an extended Reynolds-Averaged Navier–Stokes (RANS) solver were employed to predict added resistance in head waves at different Froude numbers of a Wigley hull, large tanker, modern containership. The frequency domain method, using sources as basic flow potentials, accounts for the interaction linear periodic wave-induced with nonlinear steady caused by ship's forward speed calm water, including free surface conditions dynamic squat. Added is obtained pressure...

We experimentally investigated the effect of fluid–structure interaction on unsteady cavitating flows around flexible and stiff National Advisory Committee for Aeronautics 0015 hydrofoils in a low-pressure cavitation tunnel. analyzed dynamics by capturing using two high-speed cameras at different regimes surface hydrofoils, made polyvinyl chloride, brass, aluminum. then measured associated structural deformations specific regime such as cloud partial dynamics, digital image correlation...

To validate an existing finite volume computational method, featuring a novel scheme to capture the temporal evolution of free surface, fluid motions in partially filled tanks were simulated. The purpose was compare and experimental results for test cases where measurements available. Investigations comprised sloshing rectangular tank with baffle at 60% filling level cylindrical 50% level. numerical study started examining effects systematic grid refinement concluded three-dimensionality...

The objective of the present investigation was to provide reliable experimental data suitable validate numerical tools aimed at predicting impact loads on and elastic deformations wedge-shaped structures. To investigate impact-induced hydroelastic effects slamming pressure peaks, four test bodies were examined. Two fitted with stiffened, rigid bottom plating two thin plating, each case 5° 10° deadrise angles. Results comprised pressures, accelerations, forces, structural strains. Measurement...

Two methods were compared to predict a ship’s fuel consumption: the simplified naval architecture method (SNAM) and deep neural network (DNN) method. The SNAM relied on limited operational data employed technique estimate required power by determining its resistance in calm water. Here, Holtrop–Mennen obtained hydrostatic information for each selected voyage, added encountered natural seaways, brake scenario. Additional characteristics, such as efficiency factors, derived from literature...

Within the framework of Space@Sea project, an articulated modular floating structure was developed to serve as building blocks for artificial islands. The modularity one key elements, intended provide desired flexibility additional deck space at sea. Consequently, layout a concept may change, depending on its functionality and environmental condition. Employing potential-flow-based numerical model (i.e., weakly nonlinear Green function solver AQWA), this paper studied hydrodynamic...

The purpose of this paper was to demonstrate the application a procedure predict internal sloshing loads on partially filled tank walls liquefied natural gas (LNG) tankers that are subject action sea waves. method is numerical. We used moving grid approach and finite-volume solution designed allow for arbitrary ship motions. An interface-capturing scheme accounts overturning breaking waves computed motion liquid inside tanks. suppressed numerical mixing. Mixing effects close interface were...

Abstract This paper described the process of generating optimal parametric hull shape with a fully modeling method for three containerships different sizes. The newly created ship was applied to another similar shape, which greatly saved time cost. A selecting design variables developed, and during this process, influence these on calm water resistance analyzed. After we obtained hulls, wave added motions original hulls in regular head waves were analyzed compared experimental results....

We present a numerical procedure to predict impact-related wave-induced (slamming) loads on ships. The was applied slamming two ships that feature flared bow with pronounced bulb, hull shapes typical of modern offshore supply vessels. used chain seakeeping codes. First, linear Green function panel code computed ship responses in unit amplitude regular waves. Ship speed, wave frequency, and heading were systematically varied cover all possible combinations likely cause slamming. Regular...

Model-scale measurements and full-scale sea trials were compared to numerical simulations of different ship maneuvers. Simulations performed using codes that solve the Reynolds-Averaged Navier-Stokes (RANS) equations coupled with nonlinear rigid body motion. Different time scales existing between motions fluid flow as well diverging spatial discretizations hull propulsor in conjunction propulsor's rotation increased required computational efforts, rendering model unsuitable for comprehensive...

Two Reynolds-Averaged Navier–Stokes (RANS) based field methods numerically predicted added resistance in regular head waves for a 14,000 TEU containership and medium size cruise ship. Long short of different frequencies were considered. Added was decomposed into diffraction radiation force components, whereby forces obtained by restraining the ship prescribing motions calm water. In waves, part total dominant as almost no induced. long sum exceeded resistance, i.e., interaction these two...

Assuring a ship’s maneuverability under diverse conditions is fundamental requirement for safe and economic ship operations. Considering the introduction of Energy Efficiency Design Index (EEDI) new ships related decreasing installed power on ships, necessity arose to more accurately predict in severe seas, strong winds, confined waters. To address these issues, extensive experimental numerical investigations were performed within European funded Project SHOPERA. Here, second order forces...