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Numerical study of flow-induced oscillations of two rigid plates elastically hinged at the two ends of a stationary plate in a cross-flow

Darbandi, M ; Sharif University of Technology | 2016

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  1. Type of Document: Article
  2. DOI: 10.1016/j.jfluidstructs.2016.06.013
  3. Publisher: Academic Press , 2016
  4. Abstract:
  5. The flow-induced oscillation (FIO) of bluff bodies is commonly encountered in the fluid structure interaction (FSI) problems. In this study, we use an unstructured moving grid strategy and simulate the FIO of two rigid plates, which are elastically hinged at the two ends of a fixed flat plate in a cross-flow. We use a hybrid finite-element-volume (FEV) method in an arbitrary Lagrangian–Eulerian (ALE) framework to study FIO of the two hinged plates. The current simulations are carried out for wide ranges of flow Reynolds number (50–175), spring stiffness coefficient, and the two hinged plates’ moment of inertia magnitudes. The influences of these parameters are investigated on the magnitudes of maximum deflection angle, the amplitude of oscillation, the total lift and drag coefficients, and so on. The study is also carried out in the transition period to describe the in-phase and out-of-phase angular oscillations occurring for the two elastically hinged plates with respect to each other. After the transition period, the two hinged plates eventually arrive to a similar periodic oscillation; however, with some phase lags. We find that the achieved phase lag is equal to the phase lag between the two pairs of flow vortices, which are alternatively shed into the flow from the upper and lower hinged plates. Similar to past FIO problems, the current model also exhibits two important lock-in and phase-switch FSI phenomena; however, in angular directions. There is a phase jump of approximately 170° between the aerodynamic lift coefficient and angular oscillations of hinged plates, which nearly occurs in the middle of lock-in region. Indeed, our literature review shows that this is the first time to report the phase-switch phenomenon in angular oscillations of three-element bluff bodies in a FSI problem
  6. Keywords:
  7. Flow-induced oscillations ; Finite element method ; Fluid structure interaction ; Hinges ; Locks (fasteners) ; Oscillating flow ; Reynolds number ; Amplitude of oscillation ; Flat plate ; Flow-induced oscillation ; Hybrid finite elements ; Lift and drag coefficients ; Lock-in ; Phase switch ; Unstructured moving grids ; Plates (structural components)
  8. Source: Journal of Fluids and Structures ; Volume 66 , 2016 , Pages 147-169 ; 08899746 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S0889974615300177