• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.3
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• pp.93-100
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• 2021

Since the IB (Immersed Boundary) method, which can perform coupling analysis with objects and fluids having an impermeable boundary of arbitrary shape on a fixed grid system, has been developed, the IB method in various CFD models is increasing. The representative IB methods are the directing-forcing method and the ghost cell method. The directing-forcing type method numerically satisfies the boundary condition from the fluid force calculated at the boundary surface of the structure, and the ghost-cell type method is a computational method that satisfies the boundary condition through interpolation by placing a virtual cell inside the obstacle. These IB methods have a disadvantage in that the computational algorithm is complex. In this study, the simplified immersed boundary (SIB) method enables the analysis of temporary structures on a fixed grid system and is easy to expand to three proposed dimensions. The SIB method proposed in this study is based on a one-field model for immiscible two-phase fluid that assumes that the density function of each phase moves with the center of local mass. In addition, the volume-weighted average method using the density function of the solid was applied to handle moving solid structures, and the CIP method was applied to the advection calculation to prevent numerical diffusion. To examine the analysis performance of the proposed SIB method, a numerical simulation was performed on an object falling to the free water surface. The numerical analysis result reproduced the object falling to the free water surface well.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.5
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• pp.711-721
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• 2022

Due to a long-term pandemic of COVID-19 since 2019, our society finally goes into 'un-tact (non-contact) era' in earnest by increasing an importance of non-contacted activities which are able to live without contacts among people. Un-tact era has influenced to generate a huge structural change with digitalization in our daily life as well as industrial society based on digital twin as an essential technology. As a technology representing real world in virtual digital world by integrating various technologies applied to 4^th industrial revolution, digital twin leads an innovation in industrial society with diverse industrial processes. But this technique isn't actively used across all industries due to structural limitations and environmental restrictions of digital twin. Especially, the field of construction and facility is necessary to use digital twin because it requires periodic managements of buildings in daily life and is directly connected with casualties in cases of disaster. But issues faced in reality are acting as an obstacle for applying digital twin. Therefore, this study suggests the necessity applying digital twin in facility safety response based on these issues and emphasizes active applications of digital twin by describing the expected effects being created. Furthermore, it connects to create demands of digital twin by overcoming current issues and suggesting high sustainable development.