In this paper fluid-structure interaction simulations regarding a gust generator experiment are presented, which has been conducted in 2010 in the Transonic Wind Tunnel in Gottingen (DNW-TWG), Germany. The main object...
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In this paper fluid-structure interaction simulations regarding a gust generator experiment are presented, which has been conducted in 2010 in the Transonic Wind Tunnel in Gottingen (DNW-TWG), Germany. The main objective of the experiment was the investigation of the dynamic response problem of an elastic wing model concerning an encountering generic gust induced by a gust generator. fluid-structure simulations, using a finite element structural model and a computational fluid dynamics model based on time-accurate, Reynolds-averaged Navier-Stokes equations, are compared to the experiment to validate the numerical methodology. Comparisons include steady and unsteady deflections of the elastic wing and pressure distributions. Finally, the results of simulated transfer functions of the gust generator to the elastic wing are presented in comparison to the test data. (C) 2013 Elsevier Ltd. All rights reserved.
We present a specific application of the fluid-solid interface-tracking/interface-capturing technique (FSITICT) for solving fluid-structure interaction. Specifically, in the FSITICT, we choose as interface-tracking te...
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We present a specific application of the fluid-solid interface-tracking/interface-capturing technique (FSITICT) for solving fluid-structure interaction. Specifically, in the FSITICT, we choose as interface-tracking technique the arbitrary Lagrangian-Eulerian method and as interface-capturing technique the fully Eulerian approach, leading to the Eulerian-arbitrary Lagrangian-Eulerian (EALE) technique. Using this approach, the domain is partitioned into two sub-domains in which the different methods are used for the numerical solution. The discretization is based on a monolithic solver in which finite differences are used for temporal integration and a Galerkin finite element method for spatial discretization. The nonlinear problem is treated with Newton's method. The method combines advantages of both sub-frameworks, which is demonstrated with the help of some benchmarks.
Coupled SPHS-BEM method is proposed for transient fluid-structure interaction problems: SPH shell (SPHS) is selected to discretize shell structures, the second-order doubly asymptotic approximations (DAA) of boundary ...
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Coupled SPHS-BEM method is proposed for transient fluid-structure interaction problems: SPH shell (SPHS) is selected to discretize shell structures, the second-order doubly asymptotic approximations (DAA) of boundary element method (BEM) is chosen to analyze flow-field. BEM can remedy the expensive costs for three-dimensional SPH (smoothed particle hydrodynamics), yet SPHS provides a structural solver for BEM. The coupled method is attractive, since only a layer of SPHS particles and a piece of flow-field boundary elements are needed to be modeled: the compatibility conditions of the coupled surface are performed with moving least square (MLS) function. The final two benchmarks on underwater impacts prove 1 he feasibility, stability and accuracy of the proposed method. (C) 2013 Elsevier Ltd. All rights reserved.
作者：
Yu, Y.Yang, Q.Wang, X.Tianjin Univ
State Key Lab Precis Measurement Technol & Instru Tianjin 300072 Peoples R China Brunel Univ
Sch Engn & Design Uxbridge UB8 3PH Middx England Tianjin Univ
MOEMS Educ Minist Key Lab Tianjin 300072 Peoples R China
In the study of micro aircraft flexible aerodynamic shape, the flexible structure interface deforms due to the air pressure, and this deformation simultaneously in turn affects the flow distribution around it, which i...
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In the study of micro aircraft flexible aerodynamic shape, the flexible structure interface deforms due to the air pressure, and this deformation simultaneously in turn affects the flow distribution around it, which is called a fluid-structure interaction problem. This paper discusses the general approach to such a fluid-structure interaction and further presents a detailed comparison between two representative materials used as aircraft surfaces. Two structure surfaces are respectively composed of natural rubber with high elasticity and steel alloy 1020 with high stiffness. In the test environment, the experimental model has a velocity of 8 m/s relative to the airflow, and the Reynolds number is higher than 5.44 x 10(4). The simulations of the two aerodynamic models using the two materials were performed in ANSYS CFX. The simulation results have shown that the aerodynamic shape with flexible rubber material has greater deformation and smaller force peak amplitude than the rigid material aerodynamic shape, which is a good factor to maintain flight stability. It is concluded that the flexible material with higher flexibility and shock-absorbing capability used as micro aircraft shape can play a buffer role especially in the aerodynamic disturbance. (C) 2013 Elsevier Ltd. All rights reserved.
We analyze the performances of two types of Luenberger observers - namely, the so-called Direct Velocity Feedback and Schur Displacement Feedback procedures, originally devised for elasto-dynamics - to estimate the st...
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We analyze the performances of two types of Luenberger observers - namely, the so-called Direct Velocity Feedback and Schur Displacement Feedback procedures, originally devised for elasto-dynamics - to estimate the state of a fluid-structure interaction model for hemodynamics, when the measurements are assumed to be restricted to displacements or velocities in the solid. We first assess the observers using hemodynamics-inspired test problems with the complete model, including the Navier-Stokes equations in Arbitrary Lagrangian-Eulerian formulation, in particular. Then, in order to obtain more detailed insight we consider several well-chosen simplified models, each of which allowing a thorough analysis - emphasizing spectral considerations - while illustrating a major phenomenon of interest for the observer performance, namely, the added mass effect for the structure, the coupling with a lumped-parameter boundary condition model for the fluid flow, and the fluid dynamics effect per se. Whereas improvements can be sought when additional measurements are available in the fluid domain in order to more effectively deal with strong uncertainties in the fluid state, in the present framework this establishes Luenberger observer methods as very attractive strategies - compared, e.g., to classical variational techniques - to perform state estimation, and more generally for uncertainty estimation since other observer procedures can be conveniently combined to estimate uncertain parameters. (C) 2012 Elsevier B.V. All rights reserved.
This report focuses on an analysis of the dynamic behaviour of a fluid-structure interaction system. This analysis is nonlinear, and the modal behaviour depends on many parameters, because large displacements are assu...
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This report focuses on an analysis of the dynamic behaviour of a fluid-structure interaction system. This analysis is nonlinear, and the modal behaviour depends on many parameters, because large displacements are assumed. Technical applications include vibration of blades of rotational centrifugal pumps or water turbines. A new mathematical model of a boundary condition that allow for modal analysis and calculation of the steady state or unsteady state responses is presented in this article. This condition is based on a special convolutory integral for fluid velocity and pressure and their expansion into a series of eigenmodes of structure vibration. This approach allows for the separation of the structure and the fluid. A comparison between the computational and the experimental analyses is presented. Curvilinear coordinates and a Bezier body were chosen for the description of the geometrical configuration and the approximation of the solution. (c) 2012 Elsevier Ltd. All rights reserved.
A coupling algorithm based on the finite element method and the wideband fast multipole boundary element method (FEM/wideband FMBEM) is proposed for the simulation of fluid-structure interaction and structural-acousti...
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A coupling algorithm based on the finite element method and the wideband fast multipole boundary element method (FEM/wideband FMBEM) is proposed for the simulation of fluid-structure interaction and structural-acoustic sensitivity analysis using the direct differentiation method. The wideband fast multipole method (FMM) formed by combining the original FMM and the diagonal form FMM is used to accelerate the matrix-vector products in the boundary element analysis. The iterative solver GMRES is applied to accelerate the solution of the linear system of equations. The FEM/Wideband FMBEM algorithm makes it possible to predict the effects of arbitrarily shaped vibrating structures on the sound field numerically. Numerical examples are presented to demonstrate the validity and efficiency of the proposed algorithm.
Within the group of immersed boundary methods employed for the numerical simulation of fluid-structure interaction problems, the Immersed Structural Potential Method (ISPM) was recently introduced (Gil et al., 2010) [...
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Within the group of immersed boundary methods employed for the numerical simulation of fluid-structure interaction problems, the Immersed Structural Potential Method (ISPM) was recently introduced (Gil et al., 2010) [1] in order to overcome some of the shortcomings of existing immersed methodologies. In the ISPM, an incompressible immersed solid is modelled as a deviatoric strain energy functional whose spatial gradient defines a fluid-structure interaction force field in the Navier-Stokes equations used to resolve the underlying incompressible Newtonian viscous fluid. In this paper, two enhancements of the methodology are presented. First, the introduction of a new family of spline-based kernel functions for the transfer of information between both physics. In contrast to classical IBM kernels, these new kernels are shown not to introduce spurious oscillations in the solution. Second, the use of tensorised Gaussian quadrature rules that allow for accurate and efficient numerical integration of the immersed structural potential. A series of numerical examples will be presented in order to demonstrate the capabilities of the enhanced methodology and to draw some key comparisons against other existing immersed methodologies in terms of accuracy, preservation of the incompressibility constraint and computational speed. (C) 2013 Elsevier Inc. All rights reserved.
In this paper we study a controllability problem for a simplified one dimensional model for the motion of a rigid body in a viscous fluid. The control variable is the velocity of the fluid at one end. One of the novel...
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In this paper we study a controllability problem for a simplified one dimensional model for the motion of a rigid body in a viscous fluid. The control variable is the velocity of the fluid at one end. One of the novelties brought in with respect to the existing literature consists in the fact that we use a single scalar control. Moreover, we introduce a new methodology, which can be used for other nonlinear parabolic systems, independently of the techniques previously used for the linearized problem. This methodology is based on an abstract argument for the null controllability of parabolic equations in the presence of source terms and it avoids tackling linearized problems with time dependent coefficients.
The separation dynamics of a large-scale fairing section in ground test is investigated numerically using a fluid-structure interaction method. The commercial finite element software MSC/Dytran is adopted to establish...
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The separation dynamics of a large-scale fairing section in ground test is investigated numerically using a fluid-structure interaction method. The commercial finite element software MSC/Dytran is adopted to establish the dynamic fluid-structure coupling model of the fairing. Two coupling surfaces are constructed for the inner and outer surfaces of the fairing section. The coupling equations are solved using the sequenced-coupling method, in which the fluid and structural problems are examined by the finite volume method and the finite element method, respectively. A comparison between fluid-structure interaction and dynamical response analysis is performed under the conditions with and without atmosphere effect. Results shown that the consideration of atmosphere effect will attenuate the vibration frequency and slow down the center of mass velocity. The effect of aerodynamic interference on the displacement response indicates that a maximum of 13.3% relative displacement can be induced, which may cause collision between the lower trailing portion of fairing section and the core vehicle. Therefore, it can be concluded that the fluid-structure interaction analysis is essential for evaluating and validating the reliability of separation mechanisms in ground tests.
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