Flow patterns and efficiency-power characteristics of a self-propelled, heaving rigid flat plate. (October 2016)

• Record Type: Journal Article
• Authors: Arora, Nipun; Gupta, Amit; Sanghi, Sanjeev; Aono, Hikaru; Shyy, Wei
• Is Part Of: Journal of fluids and structures. Volume 66(2016:Oct.)
• Page Start: 517
• Page End: 542
• Publication Date: 2016-10
• Subjects: Reynolds number -- Amplitude -- Density ratio -- Wing–wake interaction -- Vortex dipole -- Power and efficiency; Fluid-structure interaction -- Periodicals; Fluid mechanics -- Periodicals; Structural dynamics -- Periodicals; Structural analysis (Engineering) -- Periodicals; 620.106
• DOI: 10.1016/j.jfluidstructs.2016.08.005
• Languages: English
• ISSNs: 0889-9746

Abstract

Abstract: The aim of the present study is to characterize the flow patterns, propulsion efficiency and power requirements associated with a self-propelled-heaving thin flat plate in a quiescent medium. In this regard, a numerical model using a shifting discontinuous-grid and based upon multi-relaxation-time lattice Boltzmann method is developed to probe the resulting aerodynamics. The influence of kinematic parameters namely flapping Reynolds number Re f (20−100) and plunging amplitude β (0.2–1), and the density ratio ρ* (10 1 −10 2 ) on forward flight is pursued. Depending on the kinematics, various periodic vortex shedding characteristics of the plunging plate are observed that lead to modification of the angle of attack as a result of wing-wake interaction and downward jet. The presence of strong vortex dipole at the trailing edge with an attached leading edge vortex are factors responsible for maximum thrust generation. A wing-wake interaction which occurs at low β and high Re f due to weak vortex dissipation and presence of vortex dipole at the trailing edge acting in tandem can lead to achieving high propulsion efficiency. Through surrogate modelling, a set of Pareto-optimal solutions that describe the tradeoff between efficiency and input power for forward flight is presented and offers insight into the design and development of next generation flapping wing micro-air vehicles. Highlights: Model to probe fluid dynamics associated with a thin self-propelled, heaving rigid flat plate. Influence of flapping Reynolds number, plunging amplitude and density ratio on efficiency-power investigated. Contribution from wing-wake interaction, vortex-dipole and downwash towards thrust generation identified. Pareto-optimal solutions describe tradeoff between efficiency and input power.