In the nuclear power plant, the spent fuel pool (SFP) is an important nuclear security structure, it uses as temporary storage for spent fuel assemblies and removes the decaying heat with pool water from spent fuel as...
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In the nuclear power plant, the spent fuel pool (SFP) is an important nuclear security structure, it uses as temporary storage for spent fuel assemblies and removes the decaying heat with pool water from spent fuel assemblies. The issue of seismic safety concerning nuclear facilities has always been a primary concern for the country located in an earthquake-prone zone. When an earthquake strikes the spent fuel pool, it could lead water to sloshing behavior. It may produce additional forces on the pool and cause water overflow. It is therefore critical to investigate the sloshing phenomenon in a seismic assessment of the SFP. The objective of the paper is concerned with the problem of modeling the fluid-structure interaction (FSI) analysis with a SFP under Beyond-Design-Basis Earthquake (BDBE). The study focuses on the sloshing phenomena with the finite element analysis (FEA) code LS-DYNA. To be concerned about the structural integrity of the spent fuel pool, this paper also applied ACI-349 and ASME code to evaluate the seismic performance of the structure and the safety margin. The results show that the Taiwan BWR Mark-I Nuclear Power Plant spent fuel pool can maintain its structural integrity under the beyond-design basis earthquakes.
Bypass surgery is a commonly employed method for treating coronary artery diseases, involving the use of grafts to bypass occluded arteries. However, graft occlusion remains a concern due to mechanical disparities bet...
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Bypass surgery is a commonly employed method for treating coronary artery diseases, involving the use of grafts to bypass occluded arteries. However, graft occlusion remains a concern due to mechanical disparities between the grafts and native arteries. This study aims to compare the mechanical properties of three frequently used grafts in coronary bypass surgeries: human saphenous veins, mammary arteries, and radial arteries. Stressrelaxation tests were conducted on samples obtained from these vessels, and their mechanical properties were characterized. The stress-strain curves of each sample were fitted using the quasi-linear viscoelastic (QLV) model, with MATLAB software used to extract the model's constants. Additionally, fluid-structure simulations were performed employing the extracted viscoelastic mechanical properties of the vessels. The analysis revealed that the saphenous vein exhibited the highest elastic coefficient (0.5247) and non-linearity coefficient (0.8135) among the studied grafts. The mammary artery demonstrated nearly seven times greater viscoelasticity compared to the other graft options. Furthermore, the examination of shear stress distribution indicated lower shear stress regions in the radial and mammary artery specimens compared to the saphenous specimens. Notably, the lower wall of the host artery exhibited the greatest oscillatory shear index (OSI), with the radial specimen displaying the highest oscillation in this region compared to the other two specimens. The mechanical characterization results presented in this study hold potential applications in pathogenic and clinical investigations of heart diseases, aiding in the development of appropriate treatment approaches.
In this paper, we study the non -linear dynamic response generated as a result of a fluid-structure interaction between a flexible structure and a flowing fluid, when the structure is subjected to non -linear excitati...
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In this paper, we study the non -linear dynamic response generated as a result of a fluid-structure interaction between a flexible structure and a flowing fluid, when the structure is subjected to non -linear excitations. In first place, the use of semi-discrete approximations allowed us to show that the motion of a flexible structure coupled with a surrounding fluid flowing could be modelled and analysed via a coupled Complex Cubic Ginzburg-Landau equations (CCGLEs). Through the obtained CCGLEs, we were able to show that modulational instability (MI) is the main mechanism responsible for the generation of vortex shedding. Moreover, we showed that the stability of continuous wave depends on the coupling parameters between the fluid and the structure. Secondly, using a mathematical method, namely the G'/G expansion method, we found that vortex wave trains could be generated as cylindrical waves. These results are highly significant from a theoretical point of view and could be a plus to explain the process of generation of K & aacute;rm & aacute;n Vortex as a consequence of unstable coupling between two continuous wave in the fluid-structure system. Moreover, considering the industrial interest, such as floating wind turbines, this work aims to provide an additional understanding of the interactions between a flexible body and a surrounding flow.
We address a system of equations modeling an incompressible fluid interacting with an elastic body. We prove the local existence when the initial velocity belongs to the space H1.5+& varepsilon;\documentclass[12pt...
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We address a system of equations modeling an incompressible fluid interacting with an elastic body. We prove the local existence when the initial velocity belongs to the space H1.5+& varepsilon;\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$H<^>{1.5+\epsilon }$$\end{document} and the initial structure velocity is in H1+& varepsilon;\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$H<^>{1+\epsilon }$$\end{document}, where & varepsilon;is an element of(0,1/20)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\epsilon \in (0, 1/20)$$\end{document}.
Oil shale is characterized by a dense structure, low proportion of pores and fissures, and low permeability. Pore-fracture systems serve as crucial channels for shale oil migration, directly influencing the production...
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Oil shale is characterized by a dense structure, low proportion of pores and fissures, and low permeability. Pore-fracture systems serve as crucial channels for shale oil migration, directly influencing the production efficiency of shale oil resources. Effectively stimulating oil shale reservoirs remains a challenging and active research topic. This investigation employed shale specimens obtained from the Longmaxi Formation. Scanning electron microscopy, fluid injection experiments, and fluid-structure interaction simulations were used to comprehensively analyze structural changes and fluid flow behavior under high temperatures from microscopic to macroscopic scales. Experimental results indicate that the temperature has little effect on the structure and permeability of shale before 300 degrees C. However, there are two threshold temperatures within the range of 300 to 600 degrees C that have significant effects on the structure and permeability of oil shale. The first threshold temperature is between 300 and 400 degrees C, which causes the oil shale porosity, pore-fracture ratio, and permeability begin to increase. This is manifested by the decrease in micropores and mesopores, the increase in macropores, and the formation of a large number of isolated pores and fissures within the shale. The permeability increases but not significantly. The second threshold temperature is between 500 and 600 degrees C, which increases the permeability of oil shale significantly. During this stage, micropores and mesopores are further reduced, and macropores are significantly enlarged. A large number of connected and penetrated pores and fissures are formed. More numerous and thicker streamlines appear inside the oil shale. The experimental results demonstrate that high temperatures significantly alter the microstructure and permeability of oil shale. At the same time, the experimental results can provide a reference for the research of in-situ heating techniques in oil shale rese
The aim of the paper is the prediction of noise generated by the propeller, hydrodynamic performance and the structural behavior of the marine propeller using two-way fluid-structure interaction (FSI) method at advanc...
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The aim of the paper is the prediction of noise generated by the propeller, hydrodynamic performance and the structural behavior of the marine propeller using two-way fluid-structure interaction (FSI) method at advanced velocities of 6, 8, 10, 12 and 14 Knots. ANSYS-Workbench software is used to establish the coupling between the fluid flow and structural solver. The computed hydrodynamic performance parameters of DTMB 4119 propeller at different advanced velocities and Sound Pressure Level (SPL) at advance coefficient of 0.833 are compared with the data available in the literature and found close agreement. The validated computational methodology is applied for the two-way FSI analysis of the marine propeller. Ffowcs William's-Hawkings (FW-H) model is used to predict the noise spectrum over the frequency range of 0-10 kHz in FSI analysis. Large Eddy Simulation (LES) model is used to capture viscous effects. The speed of the propeller is 1000 rpm and advanced velocity is varied for the systematic study carried out. The effect of advanced velocity on the maximum stress induced in the propeller, deformation of the propeller, acoustic characteristics and hydrodynamic performance of the propeller are studied using FSI method.
This paper is concerned with the long-time dynamics of a fluid-structure interaction problem describing a Poiseuille inflow through a 2D channel containing a rectangular obstacle. Physically, this models the interacti...
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This paper is concerned with the long-time dynamics of a fluid-structure interaction problem describing a Poiseuille inflow through a 2D channel containing a rectangular obstacle. Physically, this models the interaction between the wind and the deck of a bridge in a wind tunnel experiment, as time goes to infinity. Due to this interaction, the fluid domain depends on time in an unknown fashion and the problem needs a delicate functional analytic setting. As a result, the solution operator associated to the system acts on a timedependent phase space, and it cannot be described in terms of a semigroup nor of a process. Nonetheless, we are able to extend the notion of global attractor to this particular setting, and prove its existence and regularity. This provides a strong characterization of the asymptotic behavior of the problem. Moreover, when the inflow is sufficiently small, the attractor reduces to the unique stationary solution of the system, corresponding to a perfectly symmetric configuration. (c) 2023 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons .org /licenses /by -nc -nd /4 .0/).
fluid-structure interaction in fluid-filled flexible pipelines is modeled herewith a time explicit nonlinear 1-D coupled approach. The internal steam-water fluid is modeled using a homogeneous equilibrium model where ...
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fluid-structure interaction in fluid-filled flexible pipelines is modeled herewith a time explicit nonlinear 1-D coupled approach. The internal steam-water fluid is modeled using a homogeneous equilibrium model where kinematic, mechanical, thermal, and thermodynamic equilibrium between liquid and steam water is assumed. As a consequence, the nonlinear convective effects are taken into account as well as the temperature variations in the fluid model. The mechanical behavior of the pipelines is obtained following the Euler-Bernoulli beam theory. This leads to structural equations taking into account axial, flexural, lateral, and torsional pipe motion. In addition, plasticity is also considered in the structural behavior. Thus, the overall model corresponds to the nonlinear extension of the so-called seven degree-of-freedom fluid-structure interaction model. Furthermore, radial expansion of the pipe cross section due to the internal fluid pressure loading is also taken into account, while the pipe radial motion is neglected. Both junction and friction coupling mechanisms are considered in the present model, whereas the Poisson coupling is ignored in this study. An explicit finite-volume method is used for approximating the fluid equations and is coupled with an explicit finite-element approach used for the structural beam equations. This leads to an explicit two-way coupling approach for fluid-structure interactions which is assessed on a selection of several experiments involving non-isothermal steam-water behavior or significant FSI effects during fast-transient events. Comparisons are given with the experimental data on all considered experiments, which clearly demonstrates the ability of the present approach to be efficient and representative.
In this paper, we study a nonlinear fluid-structure interaction (FSI) problem driven by a multiplicative, white-in-time noise. The problem consists of the Navier-Stokes equations describing the flow of an incompressib...
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In this paper, we study a nonlinear fluid-structure interaction (FSI) problem driven by a multiplicative, white-in-time noise. The problem consists of the Navier-Stokes equations describing the flow of an incompressible, viscous fluid in a 2D cylinder interacting with an elastic wall whose elastodynamics is described by membrane/shell equations. The stochastic force is applied both to the fluid equations as a volumetric body force, and to the structure as an external forcing to the deformable fluid boundary. The fluid and the structure are nonlinearly coupled via the kinematic and dynamic conditions assumed at the moving interface, which is a random variable not known a priori. Majority of the existing FSI literature builds on the assumption that the structure can only be deformed radially, neglecting its longitudinal displacement. In this article, we consider the case where the structure is allowed to have vectorial (unrestricted) deformations. (c) 2025 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://***/licenses/by/4.0/).
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