Flow patterns and efficiency-power characteristics of a self-propelled, heaving rigid flat plate
TL;DR: In this paper, a numerical model using a shifting discontinuous-grid and based upon multi-relaxation-time lattice Boltzmann method is developed to characterize the flow patterns, propulsion efficiency and power requirements associated with a self-propelled-heaving thin flat plate in a quiescent medium.
About: This article is published in Journal of Fluids and Structures.The article was published on 2016-10-01. It has received 14 citations till now. The article focuses on the topics: Starting vortex & Horseshoe vortex.
Citations
More filters
17 May 2019
TL;DR: In this article, the collective locomotion of two tandem autopropelled flapping foils is greatly affected by the phase difference, and two distinct vortex interactions are observed, merging interaction and broken interaction, which respectively result in the highest efficiency for the follower and the leader.
Abstract: The collective locomotion of two tandem autopropelled flapping foils is greatly affected by the phase difference. Two distinct vortex interactions are observed---merging interaction and broken interaction---which respectively result in the highest efficiency for the follower and the leader.
34 citations
TL;DR: In this article, the performance of a self-propelled foil in stationary fluid is numerically studied using an immersed boundary-simplified circular function-based gas kinetic method, and the results obtained indicate that there exists a threshold value of Reynolds number, and below which the propulsion performance declines considerably.
31 citations
TL;DR: In this paper, the authors present a comprehensive experimental study on harmonic oscillations of a submerged rigid plate in a quiescent, incompressible, Newtonian, viscous fluid.
Abstract: In this paper, we present a comprehensive experimental study on harmonic oscillations of a submerged rigid plate in a quiescent, incompressible, Newtonian, viscous fluid. The fluid-structure interaction problem is analyzed from both qualitative and quantitative perspectives via a detailed particle image velocimetry (PIV) experimental campaign conducted over a broad range of oscillation frequency and amplitude parameters. Our primary goal is to identify the effect of the oscillation characteristics on the mechanisms of fluid-structure interaction and on the dynamics of vortex shedding and convection and to elucidate the behavior of hydrodynamic forces on the oscillating structure. Towards this goal, we study the flow in terms of qualitative aspects of its pathlines, vortex shedding, and symmetry breaking phenomena and identify distinct hydrodynamic regimes in the vicinity of the oscillating structure. Based on these experimental observations, we produce a novel phase diagram detailing the occurrence of dis...
21 citations
TL;DR: In this paper, a fluid-structure interaction (FSI) framework based on a generalized lumped-torsional flexibility model was used to simulate a flapping wing.
Abstract: We mimic a flapping wing through a fluid–structure interaction (FSI) framework based upon a generalized lumped-torsional flexibility model. The developed fluid and structural solvers together determine the aerodynamic forces, wing deformation and self-propelled motion. A phenomenological solution to the linear single-spring structural dynamics equation is established to help offer insight and validate the computations under the limit of small deformation. The cruising velocity and power requirements are evaluated by varying the flapping Reynolds number (.
19 citations
TL;DR: In this article, the hydrodynamic behavior of an unconstrained flapping foil, which can self-propel in both longitudinal and lateral directions, is numerically studied.
Abstract: Flapping-wing-based propulsion is ubiquitous in Nature, and it is free in all directions. In this work, the hydrodynamic behaviour of an unconstrained flapping foil, which can self-propel in both longitudinal and lateral directions, is numerically studied. It is found that the flapping foil can keep self-propelling in a straight line along the longitudinal direction, together with a passive oscillation in the lateral direction. Moreover, the effects of multiple parameters on the performance of the flapping swimmer are investigated, including the flapping frequency and amplitude, the mass ratio between foil and fluid, and the thickness–chord ratio of the foil. It is shown that the propulsive speed, the power consumption and the lateral oscillating motion obey some simple scaling laws. The results obtained here may provide some light on understanding biological flapping-wing-based propulsion.
18 citations
Cites background from "Flow patterns and efficiency-power ..."
...This occurs because the heavier foil is less susceptible to fluid–structure interaction as compared with the lighter foil (Arora et al. 2016)....
[...]
...It is indicated that it is easier to achieve unidirectional propulsion for lighter and slender foils than for heavier and thicker foils (Zhang et al. 2009; Arora et al. 2016)....
[...]
References
More filters
TL;DR: An overview of the lattice Boltzmann method, a parallel and efficient algorithm for simulating single-phase and multiphase fluid flows and for incorporating additional physical complexities, is presented.
Abstract: We present an overview of the lattice Boltzmann method (LBM), a parallel and efficient algorithm for simulating single-phase and multiphase fluid flows and for incorporating additional physical complexities. The LBM is especially useful for modeling complicated boundary conditions and multiphase interfaces. Recent extensions of this method are described, including simulations of fluid turbulence, suspension flows, and reaction diffusion systems.
6,565 citations
Book•
26 Sep 2011
TL;DR: This paper is concerned with the development of methods for dealing with the role of symbols in the interpretation of semantics.
Abstract: Preface. Acknowledgements. Notation and Symbols. Part I: Terminology and Theory. 1. Introduction. 2. Concepts. 3. Theoretical Background. Part II: Methods. 1. Introduction. 2. No-Preference Methods. 3. A Posteriori Methods. 4. A Priori Methods. 5. Interactive Methods. Part III: Related Issues. 1. Comparing Methods. 2. Software. 3. Graphical Illustration. 4. Future Directions. 5. Epilogue. References. Index.
4,976 citations
3,793 citations
TL;DR: In this paper, the authors show that the enhanced aerodynamic performance of insects results from an interaction of three distinct yet interactive mechanisms: delayed stall, rotational circulation, and wake capture.
Abstract: The enhanced aerodynamic performance of insects results from an interaction of three distinct yet interactive mechanisms: delayed stall, rotational circulation, and wake capture. Delayed stall functions during the translational portions of the stroke, when the wings sweep through the air with a large angle of attack. In contrast, rotational circulation and wake capture generate aerodynamic forces during stroke reversals, when the wings rapidly rotate and change direction. In addition to contributing to the lift required to keep an insect aloft, these two rotational mechanisms provide a potent means by which the animal can modulate the direction and magnitude of flight forces during steering maneuvers. A comprehensive theory incorporating both translational and rotational mechanisms may explain the diverse patterns of wing motion displayed by different species of insects.
2,246 citations
TL;DR: The multi-objective optimal design of a liquid rocket injector is presented to highlight the state of the art and to help guide future efforts.
2,152 citations