Micro air vehicles : flapping wing propulsion

• Main Author: Chin, Shi Tong.
• Other Authors: Jorg Uwe Schluter
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering; DRNTU::Engineering::Aeronautical engineering; DRNTU::Engineering::Aeronautical engineering::Aerodynamics
• Online Access: http://hdl.handle.net/10356/53997
• Institution: Nanyang Technological University

Inspired by the efficiency of nature’s flyers, there is a growing interest amongst engineers and scientists in modelling Micro Air Vehicles (MAVs) after biological flyers. Many recent studies have been geared towards the investigation of the aerodynamics in flapping wing and the formation of the leading-edge vortex (LEV), in particular, has been established as a crucial lift-enhancing mechanism in flapping wing flight. In this FYP report, the author conducts an experimental investigation to examine the effect of Reynolds Number on the LEV and force-history of a rapidly pitched airfoil which is then held fixed at a terminal angle of attack (AoA). The focus of this project is to make comparative analyses of the experimental data obtained and validate it against the numerical study using an Immersed Boundary (IB) method conducted by Zhang et al. of a rapidly pitched flat plate. Several limitations, however, impedes direct comparisons between the experimental and numerical results. In the experimental investigation, an SD7003 airfoil is rapidly pitched to six terminal angle of attacks of 5 ̊, 10 ̊, 15 ̊, 20 ̊, 25 ̊ and 30 ̊at Re=2000, 6000 and 16416. Force readings taken from an ATI gamma force transducer are then passed through an Equiripple multiband filter consisting of a low-pass and bandpass to eliminate noise and resonance effects. Experimental results obtained demonstrate good agreement with those generated via the numerical simulations. Furthermore, both numerical and experimental results suggest that an optimal Reynolds number exist whereby flow conditions are favourable for stable and strong LEV formation.