Study on Predictability of Ocean Wave Fields based on Marine Radar Measurement Data
Abstract In this study, the predictability of ocean wave fields is considered based on marine radar measurement data. Phase-resolved components obtained by applying 3D FFT-based reconstruction to a sequence of radar images are utilized for wave field prediction, and two different prediction approaches are introduced: (i) snapshot data-based prediction through the adjustment of the frequency […]
Estimation of Significant Wave Height Using Wave-Radar Images
Abstract Characteristics of random ocean waves have been measured by different devices, and X-band marine radar is one of the typical devices. This study proposes an enhanced methodology for estimating the significant wave height of ocean waves through the analysis of X-band radar images, particularly leveraging the shadowing characteristics inherent within radar images. The enhancement […]
CFD-based hull optimization in calm water using adaptive grid deformation method
Abstract This paper presents an adaptive grid deformation technique for optimizing ship hull forms using computational fluid dynamics (CFD). The proposed method enables accurate and smooth updates of the hull surface and 3-D CFD grids in response to design variables. This technique incorporates a two-level point-transformation approach to move the grid points by a few […]
Prediction of Wave-Induced Nonlinear Ship Motions Based on an IRF-LSTM Hybrid Approach
Abstract In this study, we investigate wave-induced nonlinear ship motions using the impulse response function–long short-term memory (IRF-LSTM) hybrid approach. To achieve this, we first calculate the linear ship motions using the classical IRF method. Additionally, we introduce the LSTM technique to account for the nonlinear properties of dynamic systems. For the development of the […]
Updating the residual strength – damage index diagrams for hull girder collapse predictions of grounded ships
ABSTRACT A decade ago, the authors introduced the concept of residual strength-damage index diagrams to facilitate rapid predictions of buckling collapse in damaged structures. They demonstrated this approach with an example focused on predicting the collapse of hull girders. [Paik JK, Kim DK, Park DH, Kim HB, Kim MS. 2012b. A New Method for Assessing […]
A guidance of solid element application in predicting the ultimate strength of flat plates in compression
Abstract With the increasing demand in ocean engineering field for the ultimate limit state (ULS) analysis of thick plates, the solid (3D) element has been more frequently used in the ULS analysis. Compared to 2D element, 3D element can better consider the transverse shearing effect during the analysis which usually occurs on thick plates, due […]
An advanced design diagram of stiffened plate subjected to combined in-plane and lateral loads considering initial deflection effects
Abstract This study presents an advanced methodology for stiffened plates subjected to combined in-plane longitudinal compression and lateral loads. The proposed methodology is based on comprehensive numerical parametric analyses, and it utilises newly developed design curves for the lateral pressure limit and tailored empirical formulae for stiffened plates to increase the precision of ship structural […]
Experimental Investigation of Stress Concentration and Fatigue Behavior in 9% Ni Steel Welded Joints under Cryogenic Conditions
Abstract This experimental study delves into the intricate mechanics of stress concentration and fatigue behavior exhibited by 9% Ni steel welded joints under cryogenic conditions. The study specifically examines butt-welded, fillet longitudinal, and fillet transverse specimens, comparing their fatigue properties under room and cryogenic temperatures. Notably, determining hot-spot stress presents a challenge, as it cannot […]
Numerical analysis and parametric optimization of a direct ammonia solid oxide fuel cell system integrated with organic Rankine cycle
Abstract In this study, to maximize the electrical efficiency of the direct ammonia solid oxide fuel cell (SOFC) system, anode-off gas is recirculated for enhancing the system fuel utility and the system exhaust heat is utilized for the organic Rankine cycle (ORC) generating additional electricity. To confirm the superiority of the anode-off gas recirculation (AOGR) […]
Novel solid oxide fuel cell system integrating adsorption cooling, heating, and carbon dioxide fertilization for greenhouse tomato production
Abstract Fuel cells have been widely used for power sources in the power plant, building, and transportation sectors, while few attempts have been made to use fuel cells for agriculture. Heating costs make up a high proportion of agricultural operating costs, and fossil fuels are the primary fuels used, which affects agricultural income according to […]
