Abstract:
Flapping-wing aerodynamics has recently become an important research field for understanding the aerodynamic mechanisms used in nature for propulsion by birds, insects and fish, and for the generation of high lift and thrust for microaerial vehicles (MAVs) and submersible vehicles. MAVs are defined by the US Defense Advanced Research Projects Agency (DARPA) as flying vehicles with no overall dimension greater than 15 cm. The potential applications of such flying vehicles include civil search and rescue operations, traffic monitoring, border surveillance, wildlife surveys, power-line inspection and real-estate aerial photography. The advancement in computations has enabled us to fully understand and evaluate the highly non-linear unsteady mechanisms involved in flapping wing aerodynamics. The objective of this study is to develop strategies to correctly predict the thrust, power coefficient and efficiency for plunging airfoil motion and to analyse the flow field in order to provide insight into the physics of optimal thrust and efficiency. In this study, the commercial software package Fluent is utilised for the simulation of a 2D NACA0012 airfoil section undergoing pure plunge motion at Re = 20,000 in an incompressible flow. The dynamic mesh approach has been utilized to model the airfoil motion. By using this CFD study, we examine the effects of varying plunging parameters such as reduced frequency (k), amplitude of oscillation (h) and their product (kh) on the thrust generation and efficiency. The results are compared with experimental data and another numerical study in which the airfoil motion is implemented in the source terms of the governing equations. Although the time discretisation is only first order, the results obtained by the dynamic mesh approach are acceptable provided that sufficiently small time steps are used. The dynamic mesh approach could be easily extended to the 3D aerodynamic analysis of a flapping wing.
Page(s):
236-241
DOI:
DOI not available
Published:
Journal: Proceedings 6th International Bhurban Conference on Applied Sciences and Technology , Volume: 1, Issue: 0, Year: 2009