A unified simulation framework for fluid-structure-control interaction problems with rigid and flexible structures

2021 ◽  
Author(s):  
Chennakesava Kadapa
Keyword(s):  
Flexible Structures ◽  
Simulation Framework ◽  
Fluid Structure ◽  
Structure Control ◽  
Control Interaction

Aerodynamic Damping and Fluid-Structure Interaction of Blast Loaded Flexible Structures

2011 ◽  
Vol 82 ◽  
pp. 491-496
Author(s):  
Martien Teich ◽  
Norbert Gebbeken ◽  
Martin Larcher
Keyword(s):  
Dynamic Response ◽  
Fluid Structure Interaction ◽  
Flexible Structures ◽  
Blast Loads ◽  
Damping Term ◽  
Damping Force ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerodynamic Damping ◽  
Compliant Systems

This paper analyses the e ects of air-structure interaction of systems subjectedto weak blast loads. While these coupling e ects are negligible for typical steel or concretestructures, they may dominate the dynamic response of lighter and more exible (compliant)systems like membranes, blast curtains or cable facades. For these light and exible systems,a classical decoupled analysis, i.e., neglecting the inuence of the surrounding air, might sig-ni cantly overestimate the deections and strains. However, we show that the coupling e ectscan be accounted for by basically adding a viscous aerodynamic damping force. We discussand compare two approaches how to obtain the aerodynamic damping term. With decreasingstructural sti ness and mass, the damping contribution of air increases signi cantly. The resultsof Hydrocode simulations are presented, and an outlook into further areas of research is given.

scholarly journals Fluid–structure interaction-induced oscillation of flexible structures in laminar and turbulent flows

2013 ◽  
Vol 715 ◽  
pp. 537-572 ◽  
Author(s):  
Jorge Pereira Gomes ◽  
H. Lienhart
Keyword(s):  
Turbulent Flows ◽  
Fluid Structure Interaction ◽  
Flexible Structures ◽  
Reynolds Numbers ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Flow Disturbances ◽  
Oscillation Modes ◽  
Excited Oscillation ◽  
Excitation Mechanisms

AbstractSelf-excitation of the motion of a structure has become a prominent aspect of engineering projects over recent years as designers are using materials at their limits, causing structures to become progressively lighter, more flexible and, therefore, prone to vibrate. Stimulated by the increasing interest in fluid–structure interaction (FSI) problems, this study investigated the instability and consequent FSI-induced self-excited oscillation of flexible structures in uniform flows at Reynolds numbers between $10$ and $1. 69\times 1{0}^{5} $. The investigations were performed in both water and a highly viscous syrup ($\nu = 1. 64\times 1{0}^{- 4} ~{\mathrm{m} }^{2} ~{\mathrm{s} }^{- 1} $) and considered three structures of different geometries. The results were conclusive in showing that the motion of the structure was characterized by a sequence of oscillation modes as a function of the characteristics of the structure and flow properties. In addition, it was possible to identify the self-excitation mechanisms as being of the instability-induced excitation (IIE) or movement-induced excitation (MIE) types. IIE was observed to be the most dominant mechanism of excitation at lower velocities and it was defined by a direct relation between the flow fluctuation and natural frequencies of the structure. For that reason, IIE was strongly determined by the geometry of the front body of the structure. At higher velocities, the amplitudes of the flow disturbances generated by the structure movement increased and excitations of the MIE type became predominant for all structures. The MIE mechanism was found to be weakly influenced by the shape of the structure but very sensitive to its dynamic characteristics and to the properties of the fluid, especially the Reynolds number.

Large Motion Visualization and Estimation for Fluid-Structure Simulations

2015 ◽  
Author(s):  
Tzu-Sheng Shane Hsu ◽  
Timothy Fitzgerald ◽  
Vincent Phuc Nguyen ◽  
Balakumar Balachandran
Keyword(s):  
Objective Function ◽  
High Speed ◽  
Flexible Structures ◽  
Three Dimensional ◽  
Optimization Procedure ◽  
Fluid Structure Interactions ◽  
Displacement Fields ◽  
Fluid Structure ◽  
Computational Implementation

Studies of fluid-structure interactions associated with flexible structures such as flapping wings require the capture and quantification of large motions of bodies that may be opaque. As a case study, motion capture of a free flying insect is considered by using three synchronized high-speed cameras. A solid finite element (FE) representation is used as a reference body and successive snapshots in time of the displacement fields are reconstructed via an optimization procedure. One of the original aspects of this work is the formulation of an objective function and the use of shadow matching and strain-energy regularization. With this objective function, the authors penalize the shape differences between silhouettes of the captured images and the FE representation of the deformed body. A similar method with a three-dimensional voxel cloud (VC) reconstruction is also illustrated. Challenges faced in implementing the VC method are discussed and the current computational implementation will also be covered.

scholarly journals Investigation of Fluid-Structure Interaction Induced Bending for Elastic Flaps in a Cross Flow

2020 ◽  
Vol 10 (18) ◽  
pp. 6177 ◽  
Author(s):  
Tayyaba Bano ◽  
Franziska Hegner ◽  
Martin Heinrich ◽  
Ruediger Schwarze
Keyword(s):  
Present Model ◽  
Fluid Structure Interaction ◽  
Flexible Structures ◽  
Three Dimensional ◽  
Cross Flow ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Numerical Investigations ◽  
Transient Simulations ◽  
Ansys Workbench

With the recent increase in the design of light and flexible structures, numerical investigations of fluid and structure together play a significant role in most engineering applications. Therefore, the current study presents an examination of fluid-structure interaction involving flexible structures. The problem is numerically solved by a commercial software ANSYS-Workbench. Two-way coupled three-dimensional transient simulations are carried out for the flexible flaps of different thicknesses in glycerin for a laminar flow and Reynolds number ranging from 3 < Re < 12. The bending line of the flaps is compared with experimental data for different alignments of the flaps relative to the fluid flow. The study reports the computation of the maximum tip-deflection and deformation of flaps fixed at the bottom and mounted normal to the flow. Additionally, drag coefficients for flexible flaps are computed and flow regimes in the wake of the flaps are presented. As well, the study gives an understanding on how the fluid response changes as the structure deforms and the model is appropriate to predict the behavior of thick and comparatively thinner flaps. The results are sufficiently encouraging to consider the present model for analyzing turbulent flow processes against flexible objects.

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