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A comparative numerical study on the performances and vortical patterns of two bioinspired oscillatory mechanisms: Undulating and pure heaving

Ebrahimi, M ; Sharif University of Technology | 2015

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  1. Type of Document: Article
  2. DOI: 10.1155/2015/325934
  3. Publisher: IOS Press , 2015
  4. Abstract:
  5. The hydrodynamics and energetics of bioinspired oscillating mechanisms have received significant attentions by engineers and biologists to develop the underwater and air vehicles. Undulating and pure heaving (or plunging) motions are two significant mechanisms which are utilized in nature to provide propulsive, maneuvering, and stabilization forces.This study aims to elucidate and compare the propulsive vortical signature and performance of these two important natural mechanisms through a systematic numerical study. Navier-Stokes equations are solved, by a pressure-based finite volume method solver, in an arbitrary Lagrangian- Eulerian (ALE) framework domain containing a 2D NACA0012 foil moving with prescribed kinematics. Some of the important findings are (1) the thrust production of the heaving foil begins at lower St and has a greater growing slope with respect to the St; (2) the undulating mechanism has some limitations to produce high thrust forces; (3) the undulating foil shows a lower power consumption and higher efficiency; (4) changing the Reynolds number (Re) in a constant St affects the performance of the oscillations; and (5) there is a distinguishable appearance of leading edge vortices in the wake of the heaving foil without observable ones in the wake of the undulating foil, especially at higher St
  6. Keywords:
  7. Energy efficiency ; Finite volume method ; Maneuverability ; Reynolds number ; Vortex flow ; Wakes ; Arbitrary Lagrangian Eulerian ; High thrusts ; Higher efficiency ; Leading-edge vortices ; Lower-power consumption ; Oscillatory mechanisms ; Pressure-based ; Significant mechanism ; Navier Stokes equations ; Acceleration ; Calculation ; Comparative study ; Controlled study ; Force ; Hydrodynamics ; kinematics ; Oscillation ; Particle image velocimetry ; Priority journal ; Quantitative study ; Simulation ; Vortex motion
  8. Source: Applied Bionics and Biomechanics ; Volume 2015 , 2015 ; 11762322 (ISSN)
  9. URL: https://www.hindawi.com/journals/abb/2015/325934