检索结果-内蒙古大学图书馆

Biomechanical Evaluation of Aortic Valve Stenosis by Means of a Virtual Stress Test: A fluid-structure interaction Study

引用

ANNALS OF BIOMEDICAL ENGINEERING 2024年第2期52卷 414-424页

作者： Govindarajan, Vijay Kolanjiyil, Arun Wanna, Charles Kim, Hyunggun Prakash, Siddharth Chandran, Krishnan B. McPherson, David D. Johnson, Nils P. Univ Texas Hlth Sci Houston McGovern Med Sch Dept Internal Med Div Cardiol 1881 East Rd Houston TX 77054 USA Virginia Commonwealth Univ Richmond VA USA Sungkyunkwan Univ Suwon Gyeonggi South Korea Univ Iowa Iowa City IA USA Boston Childrens Hosp Boston MA 02115 USA Harvard Med Sch Boston MA 02115 USA

The impact of aortic valve stenosis (AS) extends beyond the vicinity of the narrowed leaflets into the left ventricle (LV) and into the systemic vasculature because of highly unpredictable valve behavior and complex blood flow in the ascending aorta that can be attributed to the strong interaction between the narrowed cusps and the ejected blood. These effects can become exacerbated during exercise and may have implications for disease progression, accurate diagnosis, and timing of intervention. In this 3-D patient-specific study, we employ strongly coupled fluid-structure interaction (FSI) modeling to perform a comprehensive biomechanical evaluation of systolic ejection dynamics in a stenosed aortic valve (AV) during increasing LV contraction. Our model predictions reveal that the heterogeneous Delta P vs. Q relationship that was observed in our previous clinical study can be attributed to a non-linear increase (by similar to 1.5-fold) in aortic valve area as LV heart rate increases from 70 to 115 bpm. Furthermore, our results show that even for a moderately stenotic valve, increased LV contraction during exercise can lead to high-velocity flow turbulence (Re = 11,700) in the aorta similar to that encountered with a severely stenotic valve (Re similar to 10,000), with concomitant greater viscous loss (similar to 3-fold increase) and elevated wall stress in the ascending aorta. Our FSI predictions also reveal that individual valve cusps undergo distinct and highly non-linear increases (>100%) in stress during exercise, potentially contributing to progressive calcification. Such quantitative biomechanical evaluations from realistic FSI workflows provide insights into disease progression and can be integrated with current stress testing for AS patients to comprehensively predict hemodynamics and valve function under both baseline and exercise conditions.

关键词： Aortic valve stenosis Exercise fluid-structure interaction Aortic hemodynamics Valve stress

来源：评论

学校读者我要写书评

暂无评论

On the multi-objective perspective of discrete topology optimization in fluid-structure interaction problems

引用

APPLIED MATHEMATICAL MODELLING 2024年 127卷 1-17页

作者： Azevedo, Anderson Soares da Costa Ranjbarzadeh, Shahin Gioria, Rafael dos Santos Silva, Emilio Carlos Nelli Picelli, Renato Univ Sao Paulo Dept Mechatron & Mech Syst Engn Polytech Sch Sao Paulo SP Brazil Univ Sao Paulo Polytech Sch Dept Min & Petr Engn Santos SP Brazil Univ Sao Paulo Polytech Sch Dept Naval Architecture & Ocean Engn Sao Paulo SP Brazil

fluid-structure interaction is a challenging topic that addresses fluid and solid physics, as well as the stress coupling between them. Traditional topology optimization methods are performed with coupling load interpolation schemes in order to have some information on fluid flow sensitivity analysis and improve compliance minimization into design-dependent problems. In this paper, we propose a strategy to design fluid-structure systems by combining solid and fluid objectives without the need for the coupling load interpolation scheme. Therefore, we investigate topology optimization applied to fluid-structure interaction problems via a multi objective formulation. We combine structural compliance with some fluid flow objective functions (energy dissipation, downforce, and drag) subject to a volume constraint. We assume linear elasticity for the solid and the steady incompressible Navier-Stokes equations for the fluid. The optimization problem is solved by using sequential integer linear programming via the TOBS (Topology Optimization of Binary structures) method with a geometry trimming (GT) technique. It is a gradient-based method that produces explicit (discrete) boundaries that are convenient for coupled physics problems. Numerical results are presented for two and three-dimensional problems considering low to moderate Reynolds numbers. We demonstrate that the proposed multi-objective approach yields physically meaningful designs with improved performance, highlighting that the incorporation of coupling load interpolation into fluid-structure interaction optimization is redundant.

关键词： Topology optimization fluid flow fluid-structure interaction Multi-objective optimization

来源：评论

学校读者我要写书评

暂无评论

A reduced smoothed integration scheme of the cell-based smoothed finite element method for solving fluid-structure interaction on severely distorted meshes

引用

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN fluidS 2024年第8期96卷 1337-1364页

作者： He, Tao Lu, Fang-Xing Ma, Xi Shanghai Normal Univ Dept Civil Engn Shanghai Peoples R China Shanghai Normal Univ Dept Civil Engn Shanghai 201418 Peoples R China

This article describes an inexpensive partitioned coupling strategy for computational fluid-structure interaction (FSI) admitting negative-Jacobian elements. The emphasis is very much on a reduced smoothed integration (RSI) scheme of the cell-based smoothed finite element method (CSFEM) using four-node quadrilateral (Q4) elements for a cost-effective solution to the Navier-Stokes (NS) equations. In the discrete fluid field, each Q4 element is considered as one single smoothing cell so as to diminish the smoothed integration loops substantially. However, the RSI scheme does not respect the stability condition of smoothed Galerkin weak-form integral in the CSFEM. To tackle this issue, a simple hourglass control is introduced to the under-integrated formulation of the NS solver. Importantly, the stabilized RSI scheme has an inbuilt advantage of its enormous tolerance towards negative-Jacobian elements. The developed technique is easy-to-implement and has been tested in various FSI examples adopting both fine and distorted meshes. This article develops a reduced smoothed integration (RSI) scheme of the cell-based finite element method for fluid-structure interaction. After introducing an hourglass control to the under-integrated formulation, the RSI scheme has an inbuilt advantage of its enormous tolerance towards negative-Jacobian elements. The proposed technique is tested, with good accuracy and higher efficiency, through various examples adopting fine and damaged meshes. image

关键词： cell-based smoothed finite element method fluid-structure interaction hourglass control mesh distortion Navier-Stokes reduced smoothed integration

来源：评论

学校读者我要写书评

暂无评论

Coupling of the immersed boundary and Fourier pseudo-spectral methods applied to solve fluid-structure interaction problems

引用

JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING 2024年第4期46卷 1-15页

作者： Nascimento, Andreia Aoyagui Mariano, Felipe Pamplona da Silveira Neto, Aristeu Padilla, Elie Luis Martinez Univ Fed Goias UFG Lab Engn Term & Fluidos LATEF Escola Engn Eletr Mecan & Comp EMC Av Esperanca s-nPredio B5 BR-74690900 Goiania Go Brazil Univ Fed Uberlandia UFU Fac Engn Mecan FEMEC Lab Mecan Fluidos MFLab Av Joao Naves de Avilla 2121Bl 5P BR-38408100 Uberlandia MG Brazil

The current manuscript addresses fluid-structure interaction (FSI) problems to the analysis of vortex-induced vibration (VIV), employing the methodology designated as IMERSPEC2D. The approach seamlessly integrates the Fourier pseudo-spectral method (FPSM) and the immersed boundary method (IBM) to solve the Navier-Stokes (NS) and continuity equations. Simultaneously, the effects of cylindrical structure, involving 1 and 2 degrees of freedom (d.o.f.) are simulated, by incorporating structural motion equations into NS via the IBM source term and implementing a two-way FSI algorithm. In the paper are presented the comparison of low and high-order temporal integration methods applied to solve the dynamic behavior of the structure and the dimensionless of the cylinder's structural motion equations, resulting in an increase in computational time step from 1E(-9\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$-9$$\end{document}) to 1E(-3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$-3$$\end{document}). Validation results to refined mesh simulations include the accurate representation of the lock-in phenomenon to simulations of 1 d.o.f. obtaining the range between reduced velocity 5.456 and 5.568 and the maximal amplitude is 0.352. Notably, the eight-shape pattern of the 2 d.o.f. cylinder displacement is obtained and the formation of C2S wake patterns is achieved, as presented by other authors. In conclusion, the dimensionless approach reduces computational time, while the high-order both of IMERSPEC methodology and time advancement integration to FSI improve the results of the cylinder's motion and alters distinct v

关键词： fluid-structure interaction Immersed boundary method Fourier pseudo-spectral method Flow over cylinder Vortex-induced vibration

来源：评论

学校读者我要写书评

暂无评论

A particle refinement technique with dynamic splitting and coalescing pattern for fluid-structure interaction problem

引用

ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS 2024年 158卷 33-50页

作者： Sun, Yijie Zhang, Kai Sun, Zhongguo Xi, Guang Xi An Jiao Tong Univ Sch Energy & Power Engn Xian 710049 Peoples R China

With the increasing demand of large scale computation, multi-resolution particle methods have been paid much attention by many researchers. In multi-resolution method, high resolution is applied in local area to reduce the whole computational costs and maintain the local accuracy. However, there are still many challenges in the stability and accuracy of multi-resolution particle methods. In this research, an efficient variable particle size (VSP) multi-resolution method, using particle splitting and coalescing techniques, is developed in moving semi-implicit particle (MPS) method. Particles split or coalesce in dynamic five steps to avoid particle overlap and clustering. The mixed splitting mechanism by combining hexagonal splitting pattern and pair splitting pattern are proposed in the five-step splitting algorithm. Pair splitting and coalescing techniques with variable particle size are proposed to strictly ensure the conservation of mass and momentum and avoid particle clustering. To solve the non-linear fluid-structure interaction problem, the VSP algorithm is introduced in MPS-DEM method. The numerical results are compared with the analytical solutions and experimental results. It shows that the proposed VSP algorithm cannot only maintain the local accuracy, but also improve the computational efficiency by avoiding unnecessary chain operations between particle splitting and coalescing.

关键词： Particle method Multi-resolution method Splitting and coalescing fluid-structure interaction Refinement

来源：评论

学校读者我要写书评

暂无评论

New modelling of column separation in pipelines with fluid-structure interaction and gas release

引用

JOURNAL OF HYDRAULIC RESEARCH 2024年第1期62卷 86-113页

作者： Ghodhbani, Abdelaziz Hadj-Taieb, Lamjed Elaoud, Sami Univ Sfax Natl Engn Sch Sfax Dept Mech Engn Lab Appl Fluid Mech Proc Engn & Environm Sfax Tunisia Prince Sattam Bin Abdulaziz Univ Coll Engn Dept Mech Engn Al Kharj Al Kharj Saudi Arabia

The efficiency of cavitation models depends on physical and dynamic parameters affecting the cavitating flow. The discrete gas cavity model (DGCM) is an efficient alternative to the discrete vapour cavity model (DVCM) in prediction of column separation in pipelines. However, pipe vibration and structural loading cannot be predicted with it. This paper deals with investigation of the coupled DGCM obtained by incorporating the classical DGCM into the governing equations of the water hammer four-equation model. The numerical procedure and the selective criterion established for the solution are novel. The pressure at specific locations of an elastic straight pipeline is predicted by use of the method of characteristics (MOC) with wave-speed adjustment (WSA) scheme. Several parameters affecting the result are investigated, but special emphasis is made on the constraint condition of the pipe. The model is validated against experimental results from the literature by performing both time and frequency analysis. The good agreement observed can allow the proposed model to be incorporated into commercial codes.

关键词： Water hammer gaseous cavitation column separation method of characteristics fluid-structure interaction constraint conditions

来源：评论

学校读者我要写书评

暂无评论

TurbineNet/FEM: Revolutionizing fluid-structure interaction analysis for efficient harvesting of tidal energy

引用

ENERGY CONVERSION AND MANAGEMENT 2024年 321卷

作者： Xu, Jian Wang, Longyan Yuan, Jianping Fu, Yanxia Wang, Zilu Zhang, Bowen Luo, Zhaohui Tan, Andy C. C. Zhan, Haifei Jiangsu Univ Natl Res Ctr Pumps Zhenjiang 212013 Peoples R China Jiangsu Univ Sch Energy & Power Engn Zhenjiang 212013 Jiangsu Peoples R China Univ Tunku Abdul Rahman LKC Fac Engn & Sci Kajang 43000 Selangor Malaysia Queensland Univ Technol Sch Mech Med & Proc Engn Brisbane Qld 4000 Australia

Horizontal axis tidal turbines (HATT) are promising candidates for hydroelectric power extraction in coastal urban applications. Currently, concerns around the fluid-structure interaction (FSI) performance of turbines limit their industrial deployment while an efficient FSI prediction model can mitigate these concepts. In this paper, we present an innovative predictive model, TurbineNet, designed to accurately forecast the FSI characteristics of diverse composite tidal turbine blade structures, thereby facilitating its performance optimization. The TurbineNet model utilizes blade mesh information as input to predict HATT performance through a neural network framework. By integrating mesh convolution and fully connected layers, the model delineates the hydrodynamic behavior of deformed blades which then couples with the finite element method (FEM) for a comprehensive dynamic FSI analysis of composite material blades. Through the generation and training of a database of deformed blades, the new TurbineNet/FEM model is capable of precisely predicting the hydrodynamic performance under various structural parameters. This approach significantly streamlines the computational process associated with traditional FSI models, reducing prediction times by nearly 18 times compared to static FSI calculations using established platforms like Ansys Workbench, while maintaining high accuracy. Based on the innovative TurbineNet/FEM model, we analyzed the FSI characteristics of three different web structures. The incorporation of web structures can substantially reduce local stress and enhance the structural stability of the blades, thus preventing vibrations. Our high-efficiency predictive FSI tool and results can aid HATTs in increasing their much-needed contribution to stability optimization design. It has the potential to significantly optimize energy conversion in tidal turbines by refining blade designs to efficiently convert the kinetic energy of tidal currents into electrical

关键词： Horizontal axis tidal turbine (HATT) Mesh convolution fluid-structure interaction Deep learning Neural Network

来源：评论

学校读者我要写书评

暂无评论

Analysis of fluid-structure interaction Mechanisms for a Native Aortic Valve, Patient-Specific Ozaki Procedure, and a Bioprosthetic Valve

引用

ANNALS OF BIOMEDICAL ENGINEERING 2024年第11期52卷 3021-3036页

作者： Fringand, Tom Mace, Loic Cheylan, Isabelle Lenoir, Marien Favier, Julien Aix Marseille Univ CNRS Cent Med M2P2 Marseille France Aix Marseille Univ La Timone Hosp APHM Dept Cardiac Surg Marseille France

The Ozaki procedure is a surgical technique which avoids to implant foreign aortic valve prostheses in human heart, using the patient's own pericardium. Although this approach has well-identified benefits, it is still a topic of debate in the cardiac surgical community, which prevents its larger use to treat valve pathologies. This is linked to the actual lack of knowledge regarding the dynamics of tissue deformations and surrounding blood flow for this autograft pericardial valve. So far, there is no numerical study examining the coupling between the blood flow characteristics and the Ozaki leaflets dynamics. To fill this gap, we propose here a comprehensive comparison of various performance criteria between a healthy native valve, its pericardium-based counterpart, and a bioprosthetic solution, this is done using a three-dimensional fluid-structure interaction solver. Our findings reveal similar physiological dynamics between the valves but with the emergence of fluttering for the Ozaki leaflets and higher velocity and wall shear stress for the bioprosthetic heart valve.

关键词： Aortic valve Ozaki procedure Neocuspidizations Valve performance Patient specific fluid-structure interaction

来源：评论

学校读者我要写书评

暂无评论

A monolithic fluid-structure interaction approach using mixed LSFEM with high-order time integration

引用

COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING 2024年 423卷

作者： Averweg, Solveigh Schwarz, Alexander Schwarz, Carina Schroeder, Joerg Univ Duisburg Essen Inst Mech Fak Ingenieurwissenschaften Abtl Bauwissenschaften Univ Str 15 D-45141 Essen Germany

This contribution deals with the solution of a new monolithically coupled fluid-structure interaction approach using mixed least -squares (LS) stress-velocity (SV) formulations with implicit time discretization schemes and adaptive time stepping. The variational approach for the fluid is based on the incompressible Navier-Stokes equations in Arbitrary-Lagrangian- Eulerian (ALE) description to consider a deforming fluid domain. For the deformation of the fluid background mesh, a pseudo -material with linear elastic behavior and local hardening using mesh-Jacobian-based stiffening is presented. The proposed LS solid formulations are based on linear and hyperelastic material behavior, and are likewise expressed in terms of stresses and velocities. In combination with conforming finite element spaces in H(div) and H1 for the spatial discretization of the unknowns, an inherent fulfillment of the coupling conditions in FSI problems is achieved. Time discretization is performed using SDIRK methods with different orders and the Houbolt method. Before solving the coupled problem, the accuracy of various high -order time discretizations is investigated when solving dynamic flow and solid problems with SV formulations. Two numerical examples with exact solution are used, i.e. an unsteady Taylor-Green vortex flow and a linear elastic vibrating plate, to evaluate the temporal convergence order of different schemes. The coupled LS FSI approach is tested by solving the benchmark problem, flow around a cylinder with attached flag, which is characterized by large deformations of the solid flag and hence the fluid domain. A major focus is on the investigation and comparison of embedded Runge-Kutta methods with adaptive time step control in terms of efficiency and performance.

关键词： fluid-structure interaction Monolithic coupling High-order time integration incompressible Navier-Stokes equations Mixed least-squares finite elements

来源：评论

学校读者我要写书评

暂无评论

Initialization Algorithms of a Rigid-Flexible Coupling fluid-structure interaction System by Considering Length-and-Area Constraints

引用

WATER 2024年第22期16卷 3265页

作者： Fang, Le Zhou, Ziyu Huang, Xingrong Li, Zhe Beihang Univ Ecole Cent Pekin Beijing 100191 Peoples R China Nantes Univ Ecole Cent Nantes CNRS LHEEAUMR 6598 F-44000 Nantes France

Rigid-flexible coupling fluid-structure interaction systems are expected to be future solutions for reducing energy lost in water. The dynamics of these systems is usually investigated via numerical simulations. However, in existing numerical works there is no accurate algorithm for the initialization of the flexible filament, which ensures both the length and area constraints, leading to inaccurate results or even severe numerical instabilities. We propose two alternative initialization algorithms, respectively, the "Trapezoidal arrangement" and the "Quartic curve arrangement". The performances of both of these two algorithms are investigated in numerical simulations by using the immersed boundary method. The motion responses and force characteristics of the flexible filament are analyzed carefully, verifying the capability of the proposed algorithms. Specifically, "Quartic curve arrangement" is further recommended due to its good property of convergence.

关键词： fluid-structure interaction initialization algorithm energy harvest immersed boundary method flexible filament

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：