检索结果-内蒙古大学图书馆

Enhancing wind energy harvesting performance of vertical axis wind turbines with a new hybrid design: A fluid-structure interaction study

引用

RENEWABLE ENERGY 2019年 140卷 912-927页

作者： Liu, Kan Yu, Meilin Zhu, Weidong UMBC Dept Mech Engn Baltimore MD 21250 USA

Vertical axis wind turbines (VAWTs) provide promising solutions for wind energy harvesting in complex flow environment. However, it is challenging to guarantee satisfactory self-starting capability and high power efficiency simultaneously in a VAWT design. To address this challenge, a new hybrid Darrieus-Modifed-Savonius (HDMS) VAWT is designed and numerically tested using a fluid-structure interaction approach based on high fidelity computational fluid dynamics. A systematic study is conducted to analyze the effects of the moment of inertia, turbine structure, and external load on the self-starting capability and power efficiency. It is found that compared with the Darrieus VAWT, the HDMS design has better self-starting capability due to the torque provided by the MS rotor at small tip speed ratios (TSRs). The larger the MS rotor is, the better the self-starting capability is. However, there is penalty on power efficiency when the size of the MS rotor increases. With an appropriately sized MS rotor, the HDMS design can maintain high power efficiency comparable with the Darrieus VAWT at large TSRs. The key flow physics is that the HDMS design can keep accelerating at small TSRs due to the inner MS rotor, and can suppress dynamic stall on the Darrieus rotor at large TSRs. (C) 2019 Elsevier Ltd. All rights reserved.

关键词： Vertical axis wind turbine Hybrid Darrieus-Modifed-Savonius design Self-starting Energy harvesting efficiency fluid-structure interaction Computational fluid dynamics

来源：评论

学校读者我要写书评

暂无评论

Parallel block-preconditioned monolithic solvers for fluid-structure interaction problems

引用

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING 2019年第6期117卷 623-643页

作者： Jodlbauer, D. Langer, U. Wick, T. Johannes Kepler Univ Linz Doctoral Program Computat Math Linz Austria Austrian Acad Sci Johann Radon Inst Computat & Appl Math Linz Austria Leibniz Univ Hannover Inst Angew Math Welfengarten 1 D-30167 Hannover Germany

In this work, we consider the solution of fluid-structure interaction (FSI) problems using a monolithic approach for the coupling between fluid and solid subproblems. The coupling of both equations is realized by means of the arbitrary Lagrangian-Eulerian framework and a nonlinear harmonic mesh motion model. Monolithic approaches require the solution of large ill-conditioned linear systems of algebraic equations at every Newton step. Direct solvers tend to use too much memory even for a relatively small number of degrees of freedom and, in addition, exhibit superlinear growth in arithmetic complexity. Thus, iterative solvers are the only viable option. To ensure convergence of iterative methods within a reasonable amount of iterations, good and, at the same time, cheap preconditioners have to be developed. We study physics-based block preconditioners, which are derived from the block-LDU factorization of the FSI Jacobian, and their performance on distributed memory parallel computers in terms of two- and three-dimensional test cases permitting large deformations.

关键词： fluid-structure interaction monolithic formulation parallel solvers physics-based block preconditioners

来源：评论

学校读者我要写书评

暂无评论

FEEDBACK STABILIZATION OF A TWO-DIMENSIONAL fluid-structure interaction SYSTEM WITH MIXED BOUNDARY CONDITIONS

引用

SIAM JOURNAL ON CONTROL AND OPTIMIZATION 2019年第5期57卷 3322-3359页

作者： Fournie, Michel Ndiaye, Moctar Raymond, Jean-Pierre Univ Paul Sabatier Toulouse III Inst Math Toulouse UMR 5219 F-31062 Toulouse France CNRS F-31062 Toulouse France

We study the stabilization of a fluid-structure interaction system around an unstable stationary solution. The system consists of coupling the incompressible Navier-Stokes equations, in a two-dimensional polygonal domain with mixed boundary conditions, and damped Euler-Bernoulli beam equations located at the boundary of the fluid domain. The control acts only in the beam equations. The feedback is determined by stabilizing the projection of the linearized model onto a finite dimensional invariant subspace. Here we have resolved two important challenges for applications in this field. One is the fact that we prove a stabilization result around a nonzero stationary solution, which is new for such fluid-structure interaction systems. The other one is that the feedback laws that we determine do not depend on the Leray projector used to get rid of the algebraic constraints of partial differential equations. This is essential for numerical aspects.

关键词： fluid-structure interaction feedback control stabilization Navier-Stokes equations beam equation

来源：评论

学校读者我要写书评

暂无评论

Numerical investigation of modal and fatigue performance of a horizontal axis tidal current turbine using fluid-structure interaction

引用

Journal of Ocean Engineering and Science 2019年第4期4卷 328-337页

作者： Habib Ullah Muzamil Hussain Naseem Abbas Hassaan Ahmad Mohammed Amer Muhammad Noman Faculty of Engineering and Technology University of LahoreLahore 54000Pakistan Department of Mechanical Engineering NFC Institute of Engineering and TechnologyMultan 60000Pakistan School of Mechanical Engineering Chung-Ang UniversitySeoul 06974Republic of Korea Department of Mechanical Engineering National Chiao Tung UniversityHsinchuTaiwan

The tidal power has the potential to play a vital role in a sustainable energy *** main objective of this paper is to investigate the performance and fatigue life of tidal current turbine(TCT)using fluid structure interaction(FSI)*** performance of TCT was predicted using Ansys *** performance curve,pressure distribution on the blade,and velocity streamline were visualized for eight repetitive analyses at different tip speed *** hydrodynamic load calculated from CFD analysis was transferred to FEA model for investigation of the structural response of *** analysis was performed to examine the mode shapes and natural frequencies of *** fatigue analysis were performed and number of cycles and safety factor at different equivalent alternating stresses were *** results of the simulation confirm that the turbine has a maximum value of the coefficient of performance atλ=5,the turbine operating frequency is not close to its natural frequency,and it is safe under the applied fatigue loads with a high factor of safety.

关键词： Tidal current turbine fluid-structure interaction Fatigue performance Computational fluid Dynamic Blade element

来源：评论

学校读者我要写书评

暂无评论

fluid-structure interaction models based on patient-specific IVUS at baseline and follow-up for prediction of coronary plaque progression by morphological and biomechanical factors: A preliminary study

引用

JOURNAL OF BIOMECHANICS 2018年 68卷 43-50页

作者： Wang, Liang Tang, Dalin Maehara, Akiko Wu, Zheyang Yang, Chun Muccigrosso, David Zheng, Jie Bach, Richard Billiar, Kristen L. Mintz, Gary S. Southeast Univ Sch Biol Sci & Med Engn Nanjing Jiangsu Peoples R China Worcester Polytech Inst Math Sci Dept 100 Inst Rd Worcester MA 01609 USA Columbia Univ Cardiovasc Res Fdn New York NY 10027 USA Washington Univ Mallinckrodt Inst Radiol St Louis MO USA Washington Univ Sch Med Cardiovasc Div St Louis MO USA Worcester Polytech Inst Dept Biomed Engn Worcester MA USA

Plaque morphology and biomechanics are believed to be closely associated with plaque progression. In this paper, we test the hypothesis that integrating morphological and biomechanical risk factors would result in better predictive power for plaque progression prediction. A sample size of 374 intravascular ultrasound (IVUS) slices was obtained from 9 patients with IVUS follow-up data. 3D fluid-structure interaction models were constructed to obtain both structural stress/strain and fluid biomechanical conditions. Data for eight morphological and biomechanical risk factors were extracted for each slice. Plaque area increase (PAI) and wall thickness increase (WTI) were chosen as two measures for plaque progression. Progression measure and risk factors were fed to generalized linear mixed models and linear mixed-effect models to perform prediction and correlation analysis, respectively. All combinations of eight risk factors were exhausted to identify the optimal predictor(s) with highest prediction accuracy defined as sum of sensitivity and specificity. When using a single risk factor, plaque wall stress (PWS) at baseline was the best predictor for plaque progression (PAI and WTI). The optimal predictor among all possible combinations for PAI was PWS + PWSn + Lipid percent + Min cap thickness + Plaque Area (PA) + Plaque Burden (PB) (prediction accuracy = 1.5928) while Wall Thickness (WT) + Plaque Wall Strain (PWSn) + Plaque Area (PA) was the best for WTI (1.2589). This indicated that PAI was a more predictable measure than WTI. The combination including both morphological and biomechanical parameters had improved prediction accuracy, compared to predictions using only morphological features. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： Coronary fluid-structure interaction Plaque progression IVUS Follow-up study

来源：评论

学校读者我要写书评

暂无评论

fluid-structure interaction and flight dynamics analysis of parachute-payload system during uncontrolled airdrop process

引用

PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART G-JOURNAL OF AEROSPACE ENGINEERING 2018年第13期232卷 2499-2512页

作者： Gao, Xinglong Zhang, Qingbin Tang, Qiangang Facil Design & Instrumentat Inst China Aerodynam Res & Dev Ctr Mianyang Peoples R China Natl Univ Def Technol Sch Aerosp Sci & Engn Changsha Hunan Peoples R China

The coupling behaviors of a special parachute's inflation incorporating fluid-structure interaction and flight dynamics are investigated based on the multibody dynamic model and LS-DYNA nonlinear analysis code. A new coupling model is developed to predict both the opening phase of parachute and the trajectory of payload during airdrop mission in low attitude. The moving mesh technology is introduced to realize the finite mass inflation simulation. A simplified integration platform is built by coupling the fluid-structure interaction and flight dynamics model, and solved based on two-way data transfer to efficiently replicate the dynamic characteristics of parachute finite mass inflation. Finally, the opening performances of the parachute at different airdropping velocities are analyzed and compared with the experimental results. The unsteady flow dynamics is simulated and the wake re-contacts phenomenon occurred. Taking consideration of the periodical disturb of wind gust, the trajectory of parachute-payload system is simulated and compared with the real airdrop test results. In conclusion, the results show that this coupling model is efficient to simulate and predict the dynamics behaviors of parachute-payload system in a finite mass inflation scenario, which will be beneficial for airdrop missions.

关键词： Parachute finite mass inflation fluid-structure interaction multibody dynamics unsteady flow

来源：评论

学校读者我要写书评

暂无评论

Monolithic cut finite element-based approaches for fluid-structure interaction

引用

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING 2019年第8期119卷 757-796页

作者： Schott, Benedikt Ager, Christoph Wall, Wolfgang A. Tech Univ Munich Inst Computat Mech Boltzmannstr 15 D-85747 Garching Germany

Cut finite element method-based approaches toward challenging fluid-structure interaction (FSI) are proposed. The different considered methods combine the advantages of competing novel Eulerian (fixed grid) and established arbitrary Lagrangian-Eulerian (moving mesh) finite element formulations for the fluid. The objective is to highlight the benefit of using cut finite element techniques for moving-domain problems and to demonstrate their high potential with regard to simplified mesh generation, treatment of large structural motions in surrounding flows, capturing boundary layers, their ability to deal with topological changes in the fluid phase, and their general straightforward extensibility to other coupled multiphysics problems. In addition to a pure fixed-grid FSI method, advanced fluid-domain decomposition techniques are also considered, leading to highly flexible discretization methods for the FSI problem. All stabilized formulations include Nitsche-based weak coupling of the phases supported by the ghost penalty technique for the flow field. For the resulting systems, monolithic solution strategies are presented. Various two- and three-dimensional FSI cases of different complexity levels validate the methods and demonstrate their capabilities and limitations in different situations.

关键词： cut elements fluid-structure interaction ghost penalty Nitsche's method unfitted finite element methods

来源：评论

学校读者我要写书评

暂无评论

fluid-structure interaction BASED ON HPC MULTICODE COUPLING

引用

SIAM JOURNAL ON SCIENTIFIC COMPUTING 2018年第6期40卷 C677-C703页

作者： Cajas, J. C. Houzeaux, G. Vazquez, M. Garcia, M. Casoni, E. Calmet, H. Artigues, A. Borrell, R. Lehmkuhl, O. Pastrana, D. Yanez, D. J. Pons, R. Martorell, J. Barcelona Supercomp Ctr Barcelona 08034 Spain CSIC IIIA Bellaterra 08193 Spain Vortex Bladeless Madrid 28232 Spain Univ Llull IQS Sch Engn Barcelona 08017 Spain

The fluid-structure interaction (FSI) problem has received great attention in the last few years, mainly because it is present in many physical systems, industrial applications, and almost every biological system. In the parallel computational field, outstanding advances have been achieved for the individual components of the problem, allowing, for instance, simulations around complex geometries at very high Reynolds numbers or simulations of the contraction of a beating heart. However, it is not an easy task to combine the advances of both fields, given that they have followed development paths in a rather independent way, and also because physical and numerical instabilities arise when dealing with two highly nonlinear partial differential equations. Nonetheless, in the last few years great advances in the coupled FSI field have been achieved, recognizing the most challenging problems to tackle and enabling a new generation of numerical simulations in aerodynamics, biological systems, and complex industrial devices. Keeping in mind that efficient parallel codes for the individual components already exist, this paper presents a framework to build a massively parallel FSI solver in a multicode coupling partitioned approach, with strong focus in the parallel implementation aspects and the parallel performance of the resulting application. The problem is casted in an algebraic form, and the main points of interest are the parallel environment needed to be able to transfer data among the codes, the location of the exchange surface, and the exchange of information among the parallel applications. The proposed framework has been implemented in the HPC multiphysics code Alya, and the multicode coupling is carried out running separated instances of this code. Two coupling algorithms with different acceleration schemes are revised, and three representative cases of different areas of interest showing the reach of the proposed framework are solved. Good agreement with litera

关键词： fluid-structure interaction HPC multicode coupling

来源：评论

学校读者我要写书评

暂无评论

fluid-structure interaction study of the supersonic parachute using large-eddy simulation

引用

ENGINEERING COMPUTATIONS 2018年第1期35卷 157-168页

作者： Yang, Xue Yu, Li Zhao, Xiao-Shun Nanjing Univ Aeronaut & Astronaut Coll Aerosp Engn Nanjing Jiangsu Peoples R China

Purpose The purpose of this study is to model the dynamic characteristics of an opened supersonic disk-gap-band parachute. Design/methodology/approach A fluid-structure interaction (FSI) method with body-fitted mesh is used to simulate the supersonic parachute. The compressible flow is modeled using large-eddy simulation (LES). A contact algorithm based on the penalty function with a virtual contact domain is proposed to solve the negative volume problem of the body-fitted mesh. Automatic unstructured mesh generation and automatic mesh moving schemes are used to handle complex deformations of the canopy. Findings The opened disk-gap-band parachute is simulated using Mach 2.0, and the simulation results fit well with the wind tunnel test data. It is found that the LES model can successfully predict large-scale turbulent vortex in the flow. This study also demonstrates the capability of the present FSI method as a tool to predict shock oscillation and breathing phenomenon of the canopy. Originality/value The contact algorithm based on the penalty function with a virtual contact domain is proposed for the first time. This methodology can be used to solve the negative volume problem of the dynamic mesh in the flow field.

关键词： Compressible flow fluid-structure interaction Breathing phenomenon Membrane structure Shock wave oscillation Supersonic parachute

来源：评论

学校读者我要写书评

暂无评论

fluid-structure interaction of patient-specific Circle of Willis with aneurysm: Investigation of hemodynamic parameters

引用

BIO-MEDICAL MATERIALS AND ENGINEERING 2018年第3期29卷 357-368页

作者： Jahed, Mahsa Ghalichi, Farzan Farhoudi, Mehdi Sahand Univ Technol Dept Biomed Engn Div Biomech Tabriz Iran Tabriz Univ Med Sci Neurosci Res Ctr Tabriz Iran

BACKGROUND: Circle of Willis (COW) is a network of cerebral artery which continually supplies the brain with blood. Any disturbance in this supply will result in trauma or even death. One of these damages is known as brain Aneurysm. Clinical methods for diagnosing aneurysm can only measure blood velocity;while, in order to understand the causes of these occurrences it is necessary to have information about the amount of pressure and wall shear stress, which is possible through computational models. OBJECTIVE: In this study purpose is achieving exact information of hemodynamic blood flow in COW with an aneurysm and investigation of effective factors on growth and rupture of aneurysm. METHODS: Here, realistic three-dimensional models have been produced from angiography images. Considering fluid-structure interaction have been simulated by the ANSYS. CFX software. RESULTS: Hemodynamic Studying of the COW and intra-aneurysm showed that the WSS and wall tension in the neck of aneurysms for case A are 129.5 Pa, and 12.2 kPa and for case B they are 53.3 Pa and 56.2 kPa, and more than their fundus, thus neck of aneurysm is prone to rupture. CONCLUSION: This study showed that the distribution of parameters was dependent on the geometry of the COW, and maximum values are seen in areas prone to aneurysm formation.

关键词： Aneurysm Circle of Willis computational fluid dynamic fluid-structure interaction

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：