Turbulent flow around flexible structures is likely to induce structural vibrations which may eventually lead to fatigue failure. In order to assess the fatigue life of these structures, it is necessary to take the action of the flow on the structure into account, but also the influence of the vibrating structure on the fluid flow. This is achieved by performing fluid-structure interaction (FSI) simulations. In this work, we have investigated the capability of a FSI toolkit for the finite volume computational fluid dynamics software foam-extend to simulate turbulence-induced vibrations of a flexible structure. A large-eddy simulation (LES) turbulence model has been implemented to a basic FSI problem of a flexible wall which is placed in a confined, turbulent flow. This problem was simulated for 2.32 seconds. This short simulation required over 200 computation hours, using 20 processor cores. Thereby, it has been shown that the simulation of FSI with LES is possible, but also computationally demanding. In order to make turbulent FSI simulations with foam-extend more applicable, more sophisticated turbulence models and/or faster FSI iteration schemes should be applied.

#2Lars Davidson(Chalmers University of Technology)H-Index: 51

Large-eddy simulations (LES) were used to predict the neutral atmospheric boundary layer over a sparse and a dense forest, as well as over grass-covered flat terrain. The forest is explicitly represented in the simulations through momentum sink terms. Turbulence data extracted from the LES served then as inflow turbulence for the simulation of the dynamic structural response of a generic wind turbine. In this way, the impact of forest density, wind speed and wind-turbine hub height on the wind-t...

Abstract A nonlinear model for fatigue damage accumulation under variable amplitude loading is presented. The known assumption that the isodamage curves are converging at the knee point of the S-N curve of the material, has been adopted. The proposed model does only require one parameter, in addition to the S-N curve of the material, in order to calculate the remaining fatigue life. A single value for the parameter has been found to give satisfying agreement with experimental data for four arbit...

#1Vinh-Tan Nguyen(Agency for Science, Technology and Research)H-Index: 10

#2Hoang Huy Nguyen(Agency for Science, Technology and Research)H-Index: 4

Abstract This work presents a development of computational fluid dynamic model for numerical simulations of flow induced vibrations, important physical phenomena characterizing operations of various engineering structures, especially offshore installations including risers and platforms. We propose an application of detached eddy simulation (DES) approach for simulations of incompressible Navier–Stokes flows over cylindrical structures coupled with its rigid body motions. In this approach, a hyb...

Current industrial practice for the fluid–structure interaction (FSI) analyses and prediction of aeroelastic phenomena, such as flutter, is heavily based on linear methods. These methods involve many of design limitations and envelope restrictions for aircraft. In this paper novel hybrid Reynolds-Averaged Navier–Stokes – Large Eddy Simulation (RANS–LES) turbulence model, i.e. k–Omega Shear Stress Transport Scale-Adaptive Improved Delayed Detached Eddy Simulation (k –Omega SST SA IDDES) is tested...

Abstract Within the last decade, very sophisticated numerical methods for the iterative and partitioned solution of fluid–structure interaction problems have been developed that allow for high accuracy and very complex scenarios. The combination of these two aspects–accuracy and complexity–demands very high computational grid resolutions and, thus, high performance computing methods designed for massively parallel hardware architectures. For those architectures, currently used coupling methods, ...

#1T. Gillebaart(TU Delft: Delft University of Technology)H-Index: 5

#2D.S. Blom(TU Delft: Delft University of Technology)H-Index: 5

Last. Hester Bijl(TU Delft: Delft University of Technology)H-Index: 28

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Abstract Consistent time integration on collocated grids for incompressible flow has been studied for static grids using the PISO method, in which the dependencies on time-step size and under-relaxation has been studied in detail. However, for moving grids a detailed description is still missing. Therefore, a step by step analysis of a time consistent fluid–structure interaction (FSI) method for incompressible flow on collocated grids is presented. The method consist of: face normal and area cor...

The wake flow behind a cantilever beam of quadratic cross-section at a Reynolds number of 50,000 is investigated using detailed simulations. Two cases are considered, the first one using a stiff beam and the second one with a beam allowing for elastic deformation due to the hydrodynamic forces. The flow is simulated using an implicit large eddy simulation (ILES) approach in OpenFOAM and the structural deformation of the beam is found from a non-linear finite element approach using OOFEM. The mot...

#2Muk Chen Ong(NTNU: Norwegian University of Science and Technology)H-Index: 13

Last. Dag Myrhaug(NTNU: Norwegian University of Science and Technology)H-Index: 26

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Abstract Numerical investigations of the flow normal to a flat plate with the thickness ratio (thickness/height) of 0.02 have been carried out using three-dimensional large-eddy simulations (LESs). The Reynolds number (Re) based on the height of the plate (H) is 1.5 × 10 5 . The plate corners are rounded with the curvatures of two different radii, i.e. r = 0.01 H and 0.005 H . A low-frequency unsteadiness is indicated in the flow patterns and the flow switches alternately between the high and lo...

The paper focuses on the study of a semi-activated system, based on a combination of two movements of forced pitching and free-heaving motion. Therefore, quantifying with accuracy the hydrodynamic forces applied on the hydrofoil seems to be crucial. This is investigated throughout a numerical analysis of the hydrofoil dynamics. The deformable structure is oscillating in a low-Reynolds number flow. In this study, a hydrofoil animated by a combined forced pitching and heaving movements is consider...

Last. Gianluigi Rozza(SISSA: International School for Advanced Studies)H-Index: 39

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We consider the interaction of an incompressible fluid described by a Leray model with a hyperelastic structure modeled as a Saint Venant-Kirchhoff material. We focus on a strongly coupled, partitioned fluid-structure interaction (FSI) solver in a finite volume environment, combined with an arbitrary Lagrangian-Eulerian approach to deal with the motion of the fluid domain. The main novelty of this paper lies in applying a Leray model for the description of the flow field within a FSI context. Fo...

Abstract This paper investigates the fluid-structure interaction (FSI) that would be expected to occur when a lost core deforms in high-pressure die casting. A two-phase compressible Volume of Fluid approach is used to model the fluid. The turbulence contribution to the Navier-Stokes equations is accounted for by using the Reynolds-averaged Navier Stokes (RANS) Menter SST k − ω model, whilst an isotropic linear elastic model is assumed for the core material itself. The computed results for the c...